Prominent lateral palatine ridges: developmental and clinical relevance.

Unusually prominent lateral palatine ridges have been found to be a nonspecific feature of a variety of disorders in which there is either neuromotor dysfunction or a malformation which prevents tongue thrust into the palatal vault. Observations of the lateral palatine ridges in 3 fetal specimens and in 260 normal individuals over a wide range of ages revealed that these structures are normally more prominent during prenatal life and infancy. With increasing age these ridges normally become progressively flattened and usually disappear by age 5 years. The observation of unusual prominence of these ridges in infants with neuromuscular dysfunction as well as in those with malformations which limit tongue thrust into the palatal vault suggests that a long-standing deficit of tongue thrust is the common pathogenetic mechanism. Prominent lateral palatine ridges may be misinterpreted as a true "narrow, high-arched palate", which is a much less common anomaly. This distinction is important clinically, since prominent lateral palatine ridges most commonly imply a long-term deficit of neuromuscular function and thus may be an important diagnostic clue to alterations dating back to early prenatal development.


Diagnosis of lipogranulomatosis (Farber disease) by use of cultured fibroblasts.

The enzyme defect in Farber disease, a deficiency of acid ceramidase, has been demonstrated in cultured skin fibroblasts, which provides a means of confirming the diagnosis during life. The assay can also be performed using cultured amniotic fluid cells and is a potential tool for detection of carriers of the disease.


Epidemiology of high-tension electrical injuries in children.

Twenty-seven acute high-tension electrical injuries were seen in seven years at the Shriners Burns Institute. All were in boys 7 to 16 years old; 13 suffered amputation(s) and 2 died. Most accidents occurred when boys climbed utility poles (9), trespassed, generally around transformer substations (9), or contacted power lines when tree climbing (5). All occurred in daylight, generally between 4 and 6 PM, on weekends in warm weather with boys in groups. Preventive education directed to this high-risk population should illustrate properties of high-voltage electricity, effects on the body, and how to cope with peer pressures in unstructured time.


Redescription of oocysts of the bovine coccidia Eimeria bukidnonensis Tubangui 1931 and E. wyomingensis Huizinga and Winger 1942.

Oocysts of Eimeria bukidnonenisis and E. wyomingensis were found to be morphologically similar, and could be reliably differentiated only by measurements. Pyriform oocysts of E. bukidnonensis measured 43 to 51 by 30 to 35 mum (mean 47.4 by 33.0 mum); sporocysts were 18 to 21 by 9 to 11 mum (mean 19.6 by 9.8 mum). Micropyle present; polar granule, oocyst residuum, and sporocyst residuum absent. Oocyst wall of 2 layers, 3.5 mum thick, and dark brown. Pyriform oocysts of E. wyomingensis measured 36 to 44 by 26 to 30 mum (mean 39.9 by 28.3 mum); sporocysts were 17 to 20 by 8 to 10 mum (mean 18.7 by 8.6 mum). Micropyle present; polar granule, oocyst residuum, and sporocyst residuum absent. Oocyst wall of 2 layers, 2.5 mum thick, and colored brown. The width of the oocyst was the most reliable criterion for differentiating the 2 species.


Miracidium of Allocreadium fasciatusi Kakaji 1969 (Trematoda: Allocreadiidae).

The miracidium of Allocreadium fasciatusi has 18 epidermal cells arranged in 3 tiers according to the formula 6,8,4. In the posterior part of the miracidium there is a fully formed redia while the anterior part contains 2 fluid-filled refractile sacs which appear to store the waste material released by the redia. The 2 excretory pores of the miracidium are middorsal and midventeral rather than lateral.


Patterns of argentophilic papillae of Schistosoma rodhaini and S. mansoni cercariae.

Argentophilic papillar patterns on cercariae of Schistosoma rodhaini from Kenya and S. Africa, and S. mansoni from Kenya and Brazil were compared with each other and with earlier results on cercariae of a Puerto Rican stock. The basic total number of papillae of both species is the same (62), and the basic numbers of papillae in the various groups are the same: dorsal, 20; ventral, 18; lateral, 10 on each side; and acetabular, 4. The cercariae of these 2 species differ, however, in patterns of papillae, chiefly the dorsal patterns, and can be distinguished from each other.


Seasonal periodicity of three species of caryophyllaeid cestodes in the creek chubsucker, Erimyzon oblongus (Mitchill), in North Carolina.

One hundred and seventy-two specimens of Erimyzon oblongus from Lake Raleigh, North Carolina, were examined for caryophyllaeid cestodes from December 1972 to July 1974. Monobothrium ulmeri, Biacetabulum meridianum, and an undescribed species of Penarchigetes were recovered from the "stomach," "pyloric bend," and the first loop of the small intestine of the suckers. Infections of M. ulmeri were limited to an 8-month period and were seasonally periodic in prevalence, mean intensity, maturation, and length distribution. A "temperature dependeant rejection response" is discussed as a possible factor involved in the periodicity of this species. The maturation of M. ulmeri corresponded closely to the host's reproductive cycle, and may have been affected by changes in the host's hormonal levels during the spring. Infections of R. meridianum were present throughout the year, and exhibited a seasonal periodicity in prevalence, maturation, and length distribution. The mean intensity of infection suggests that the establishment of this species is inhibited by heavy burdens of M. ulmeri. Penarchigetes sp. was nonseasonal in prevalence, mean intensity, and maturation. The continuous availability of infective procercoids and the lack of a sucker "rejection response" are discussed as possible explanations for this destribution. Unlike B. meridianum and Penarchigetes sp., the mean intensity of M. ulmeri showed a close relationship with host sex.


Nerves originating from the cerebral ganglion of Moniliformis moniliformis (Acanthocephala).

Extending from the cerebral ganglion are the following 6 pairs of nerves: 2 pairs of anterior medial nerves, 2 pairs of lateral medial nerves, 1 pair of anterior proboscis nerves, 1 pair of lateral medial nerves. The dorsal anterior medial nerve and the ventral anterior medial nerve are unpaired nerves. The dorsal anterior medial nerve supplies the apical sensory device on the proboscis. The ventral anterior medial nerve supplies the retractor and protrusor muscles of the proboscis and the lateral posterior nerve supplies the longitudinal and circular muscles of the body wall. This last nerve is the largest of the nerves and is enclosed by the retinacular muscle as it extends through the pseudocoel to the body wall where it divides into a posterior and anterior nerve. The anterior medial nerve originates from 2 different levels along the dorsal anterior surface of the ganglion. These nerves serve the anterior presoma. The anterior proboscis nerve originates from the apical cells of the ganglion and is found between the proboscis retractor muscles throughout their length.


Diplotriaena darnaudii sp. n. (Nematoda: Diplotriaenidae) from D'Arnaud's barbet, Trachyphonus darnaudii.

Diplotriaena darnaudii sp. n. is described from 13 specimens collected from the thoracic air sacs of a D'Arnaud's barbet (Trachyphonus darnaudii) originating in the Lake Baringo area of Kenya and which died in captivity in Canada. In morphology it is similar to D. bargusinica Skrjabin 1917, D. campanae Anderson 1959, D. dollfusi Anderson 1959, and D. epsilon Johnston and Mawson 1940, but can be separated from these species by combinations of trident size and spicule size and morphology.


Transplacental migration of Toxocara canis larvae in experimentally infected mice.

In experimentally infected, nonpregnant mice the larvae of Toxocara canis were not found in the uterus at any time. In mice infected at 1 week, but not at 2 weeks, before gestation, larvae were found in the uterus but not in either the placenta or fetus. In mice infected during pregnancy, larvae were found in the uterus and placenta from the 9th day and in the fetus from the 11th day of pregnancy, more abundantly when infected at the middle than at the earlier stages. Examination of microsections revealed larvae in both maternal sinusoidal spaces and fetal blood vessels of the placenta; though mechanical damage to the tissues and the debris of tissues were sometimes seen, larva-associated inflammation in these tissues were not observed. The results suggest that in the pregnant mouse the migration of T. canis larvae is influenced by the developmental stages of the placenta.


Nasal mites of the subfamily Speleognathinae (Ereynetidae) from birds in Texas.

Nasal mites of the subfamily Speleognathinae were recovered from several species of birds in Texas. New host records include Ophthalmophagus striatus (Crossley) 1952 from Columbigallina passerina, Boydaia clarki Fain 1963 from Callipepla squamata, Boydaia falconis Fain 1956 from Falco sparverius, and Boydaia tyrannus Ford 1959 from Myiarchus cinerascens. Also recovered was Astrida coccyzae Pence 1972 from Coccyzus americanus. Boydaia pheucticola sp. n. from Pheucticus melanocephalus is described. It differs from similar species in the adult female by having the coxal setae formula 2-1-2-0, sensillae clavate but not globose or subglobose, and interior seta on coxa I reduced in size but not vestigial. The larva is differentiated by the modified legs II with one long recurved hooklike claw and a shorter curved claw.


Reproductive morphology of Ornithonyssus sylviarum (Canestrini and Fanzago) (Acari: Macronyssidae).

The male reproductive system consists of paired tests, vasa deferentia and dark-staining lateral accessory glands, single ventromedial spongy accessory gland, seminal vesicle, ejaculatory apparatus, and gonopore. The female system consists of paired rami sacculi, sacculus foemineus, ovary (lyriform and medial portions), oviduct, vagina, and paired vaginal glands.


Differential variation of parthenogenetic and bisexual Haemaphysalis longicornis (Acari: Ixodidae).

Morphological characters are measured from each tick specimen from samples of 10 "populations" of Haemaphysalis longicornis. The 10 populations consist of 6 diploid bisexual and 4 triploid parthenogenetic populations from Australia, Japan, and Korea. Statistical analyses (univariate and multivariate) of differential morphological variation are made among sex, method of reproduction, and chromosome ploidy level in attempts to determine the effects of these parameters on overall variation. In general, laboratory-reared thelytokous females (3n = 33y are least variable, laboratory-reared bisexual females and males (2n = 22 female; 21 male) are intermediate in variation, and field-collected bisexual males and females are most variable. However, the only field-collected thelytokous "population" (3n = 33) in the analyses is more variable than even the field-collected bisexual ticks.


Boophilus microplus: passive transfer of resistance in cattle.

Plasma from cattle highly resistant to the tick Boophilus microplus conferred some resistance to unexposed calves. In contrast plasma from hosts of low resistance had no significant effect compared with plasma from unexposed donors.


Programmed diffusional release rate from encapsulated cosolvent system.

The programmed diffusional release rate of an active agent through a rate-controlling membrane from a cosolvent system is discussed. At initial conditions, the drug is present below saturation in solution in a solvent mixture, enclosed by the rate-controlling membrane; the solvent is composed of the main solvent and a consolvent, which increases the drug solubility in the main solvent. During operation, the active agent and cosolvent diffuse from the capsule at a rate controlled by the membrane. Equations were derived describing the release rate of the active agent as a function of the permeability of the cosolvent and agent, the capsule dimensions, and the system's initial conditions. A great variety of release rate profiles can be programmed from declining to increasing delivery rate patterns as a function of time. Experimental data are presented for the drug progesterone in solution in cyclohexane with methyl, heptyl, or cetyl alcohol as the cosolvent in a polyethylene capsule. The theory qualitatively predicts the theory qualitatively predicts the experimental results.


Bioavailability of 17 ampicillin products.

The bioavailability of single lots of 250-mg ampicillin capsules, available from 17 distributors and/or manufactures, was determined. Each product was evaluated in terms of the serum ampicillin levels achieved at 1, 2, 3, 4, 6, and 8 hr postadministration, the peak serum levels, the time of peak serum level, and the area under the serum level-time curve. There was no statistically significant difference (p is greater than 0.05) between any of the 17 products tested.


Solubilities of testosterone propionate and related esters in organic solvents.

The solubility parameters of a range of saturated hydrocarbons were calculated from vapor pressures and heats of vaporization. Solubilities of testosterone propionate were determined in these solvents at 25 degrees and yielded solute solubility parameters which varied from solvent to solvent. The solubility parameter of testosterone propionate was determined by several other methods, and support was found for the previously published figure of 9.5 cal(1/2) cm(-3/2). The geometric mean coefficient (l(12)) in saturated hydrocarbons was found to be a rectilinear function of the branching ratio (r). The mean l(12) of androstanolone and testosterone propionates was used to calculate the solubilities of other esters, giving good agreement with experimental results. IR data, presented as the sum of the shifts of the 3-keto and 17-ester carbonyl stretching frequencies in polar solvents, correlated rectilinearly with the geometric mean coefficients and the plot extrapolated to the l(12) value of n-hexane, calculated from the branching ratio plot. Attempts to predict solubilities of other esters in polar solvents using l(12) values achieved only limited success.


Synthesis of 3-substituted thieno [2, 3-d] pyrimidin-4(3H)-one-2-mercaptoacetic acids and their ethyl esters for pharmacological screening.

3-Substituted thieno [2, 3-d] pyrimidin-4(3H)-one-2-mercaptoacetic acids and their ethyl esters were synthesized from 2-mercaptothieno [2, 3-d] pyrimidin-4(3H]-ones, which were obtained by cyclization of thienylthioureas in acidic medium. Analgesic, anti-inflammatory, and anticonvulsant activities were found in some of these compounds. Significant antimicrobial activity was exhibited by thienylthioureas.


GLC analysis of thioridazine, mesoridazine, and their metabolites.

A GLC method for measuring thioridazine, mesoridazine, their metabolites, and possibly other phenothiazines was developed. By using this method, seven different phenothiazine derivatives, thioridazine, and six known thioridazine metabolites were extracted and separated. This method was tested by assaying plasma samples from 30 hospitalized psychiatric patients receiving thioridazine or mesoridazine.


GLC assay of belladonna extracts.

Samples of belladonna pilular and powdered extract and tincture from two suppliers were analyzed by GLC as a cooperative effort between two laboratories to develop methodology with substantial improvements in sensitivity, specificity, precision, and working time over the present official method. This goal was achieved, but marked differences in response of the individual extracts to different isolation schemes were noted.


Dissolution rate studies of cholesterol monohydrate in bile acid-lecithin solutions using the rotatingdisk method.

A physical model approach was used to investigate cholesterol gallstone dissolution kinetics in simulated bile. Critical experimental and theoretical investigations simulating in vivo conditions showed that, in the bile acid-lecithin solutions, there is a significant interfacial barrier for both cholesterol gallstone and cholesterol monohydrate pellet dissolution. In the present study, the rotating-disk dissolution method and the accompanying Levich theory were applied to assess the contributions of the diffusion convection mass transfer resistance and of the interfacial barrier to the overall kinetics. Cholesterol dissolution rates in bile acid solutions were about 2-20 times slower than diffusion-controlled rates depending upon the degree of agitation. As found in previous studies, these rates in the presence of sufficient concentrations of dissolution accelerators approached the theoretical diffusion-convection-controlled rates. To account for the much slower dissolution rates in bile acid-lecithin solutions, two possible kinetic interpretations were investigated. The first is based upon slow crystal-micellar solution interfacial kinetics, and the second is based upon a slow rate of cholesterol solubilization in the aqueous diffusion layer. For the latter, an analytical mathematical solution was obtained.


Chlorpromazine metabolism VII: new quantitative fluorometric determination of chloropromazine and its sulfoxide.

A new, sensitive assay is described for chlorpromazine and/or its sulfoxide. The method is based on reacting the tertiary amine base with 9-bromomethylacridine to form a quaternary compound which, on photolysis, yields highly fluorescent products that are determinable fluorometrically. The procedural steps were standardized, and an optimum assay procedure was developed. The method shows a less than 3% coefficient of variation when applied directly to chlorpromazine samples and is capable of determining 15-20 ng of the drug. The method is readily adaptable to clinical and bioavailability studies.


Bumetanide: radioimmunoassay and pharmacokinetic profile in humans.

A simple, specific, and sensitive radioimmunoassay was developed for the determination of the diuretic bumetanide in plasma and urine. Antiserum to bumetanide was obtained from rabbits immunized with an immunogen prepared by covalently coupling the glycine conjugate of bumetanide to bovine serum albumin. Following extraction of the sample at pH 5.5 with ether, radioimmunoassay of the residue from the ether extract allows for the determination of bumetanide with a limit of sensitivity of about 1 ng/ml using 0.1 ml of plasma or urine. The specificity of the radioimmunoassay was established by comparison with specific radiometric and spectrofluorometric techniques. The pharmacokinetic profile of bumetanide in eight human subjects receiving single 2-mg oral doses of the drug was elucidated using the radioimmunoassay. The peak plasma levels ranged from 39 to 50 ng/ml at 1-4 hr after administration and declined with a mean apparent half-life of 1.17 hr. The mean plasma clearance rate was calculated to be 255 ml/min. During the first 24 hr, a mean of 43% of the bumetanide dose was excreted in the urine as intact drug.


Muscle relaxant properties of chloramphenicol.

Experiments with the guinea pig ileum, guinea pig trachea, rat fundal strip, rat colon, rat vas deferens, and toad heart indicated that chloramphenicol inhibited smooth muscles, decreasing both the height and frequency of spontaneous contraction. Chloramphenicol-induced relaxation was not mediated through adrenergic, cholinergic, or histaminergic mechanisms. The degree of muscle relaxation was related to the concentration of chloramphenicol, and the relaxant effect could be reversed by removing chloramphenicol from site of action by washing. Its action appears to be direct on the muscle, possibly by interfering with the energy-generating mechanism.


Controlled drug permeation I: controlled release of butamben through silicone membrane by complexation.

The effects of caffeine, beta-cyclodextrin, and povidone on the permeation behavior of butamben from saturated solutions in these complexing agents through a dimethyl polysiloxane membrane were investigated at 30 degrees. In all systems, these agents increased the rate of release over the plain saturated drug solution. The effect was more pronounced with caffeine and beta-cyclodextrin than with povidone. Interpretation of these results with the aid of solubility data for the corresponding systems led to the following generalization. For a fixed total (free and complexed) amount of drug available for release, sustained release is associated with systems containing more stable complexes. The practical value of this approach to the controlled release of drug is discussed.


Pharmacokinetic model for simultaneous determination of drug levels in organs and tissues.

An extension of the Bischoff-Dedrick pharmacokinetic model is presented. This model is derived from basic considerations of drug distrubition with physiological and anatomical meaning. The Bischoff-Dedrick model can simultaneously predict drug distribution with time in blood, organs, and tissues of pharmacological interest. The parameters are applied to a 15-kg standard dog. The experimental kinetic data of thiopental in brain, plasma, liver, lean tissue, and adipose tissue in a dog are used to demonstrate the feasibility of the model. Allowable variations in the parameters are determined. In general, the kinetics of drug distribution in blood, organs, and tissues depend on the drug dosage, lipid solubility, partition coefficients, metabolism rate, excretion rate, protein binding, route of administration, sizes of organs and tissues, and blood flow rates through organs and tissues. These factors enter the kinetic model separately and explicitly so their effects on the kinetics of drug distribution can be studied to provide valuable information for optimal therapy.


Hypocholesterolemic agents IV: inhibition of beta-hydroxy-beta-methyglutaryl coenzyme A reductase by arylalkenyl and arylepoxy hydrogen succinates and glutarates.

Two series of half acid esters of succinic and glutaric acids were synthesized and assayed for inhibition of rat liver beta-hydroxy-beta-methylglutaryl coenzyme A reductase. Irreversible inhibition was studied by incorporation of a potential alkylating group (the epoxide function) into the side chain of the alcohol portion of the half acid esters. Incorporation of a terminal olefin function into the side chain of the alcohol portion of the half acid esters provided a group that could form a charge-transfer complex. Neither irreversible inhibition nor formation of a charge-transfer complex was indicated from these studies; however, the two series of half acid esters exhibited reversible inhibition.


Continuous-flow system for determination of diffusion coefficients: use of a natural membrane.

A natural membrane was employed in an automated diffusion system. A mature male Mongolian gerbil sebaceous gland pad was excised and mounted into a suitable retainer so that the external surface was oriented toward the concentrated aqueous drug solution. Aqueous solutions of benzoic acid and the three commonly used parabens were studied. The gerbil sebaceous pad effectively prevented any diffusion of these drug solutions within 15 hr. Water by itself, however, was transported through the skin even against a pressure gradient. Although no apparent diffusion of these compounds occurred, a significant amount of drug was retained by the sebaceous pad. An expression for membrane-water partition coefficients could be calculated. Based upon thicknesses of natural and synthetic membranes, theoretical approximations of diffusion rates were found using lag time calculations.


Nonspecific effect of bis(2-ethylhexyl) phthalate on hexobarbital sleep time.

The data presented suggest that the intravenous or intraperitoneal administration of bis(2-ethylhexyl) phthalate prolongs hexobarbital sleep time in mice and rats by enlarging the lipophilic pool, a phenomenon that can be replicated by pretreatment of the animals with olive oil. These results call attention to the importance of considering the physical characteristics of a substance when evaluating its effect on a pharmacologically active agent.


Interference by butyl rubber stoppers in GLC analysis for theophylline.

During a study of the pharmacokinetics of theophylline using GLC analysis, unexpectedly high values occurred in a random manner. The cause of there abnormal values was investigated, and significant interference was observed when blood samples were drawn using evacuated glass tubes sealed with butyl rubber stoppers. In vitro tests using distilled water showed no apparent theophylline levels due to the additives in three commonly used tubes. However, when water was allowed to remain in contact with the butyl rubber stoppers for 1 min, an apparent theophylline content of as high as 5.5 mug/ml was observed. A contact time of 60 min resulted in apparent theophylline levels of as high as 52.3 mug/ml. It was concluded that a substance leached from the butyl rubber stoppers accounted for the spurious results.


Isolation of pinastric acid and ergosterol from Parmelia caperata (L.) Arch.

Among other common compounds, pinastric acid and ergosterol were isolated for the first time from Parmelia caperata. The isolation of these compounds is described; identification was made from the melting point and UV, IR, and mass spectral data.


Quantitative NMR analysis of a four-component mixture of phenylglycine derivatives.

A rapid, accurate, and precise NMR analytical method for the analysis of phenylglycine, dihydrophenylglycine, tetrahydrophenylglycine, and cyclohexylglycine in combination with each other was developed. The method is based on the integration of the NMR signal characteristic of each component relative to the signal from tetramethylammonium bromide, which is added as an internal standard. No prior separation of the four components is required.


Electron-capture GLC determination of phenylpropanolamine as a pentofluorophenyloxazolidine derivative.

A simplified procedure is described for an electron-capture GLC determination of phenylpropanolamine in blood plasma. The method is based on derivatization of phenylpropanolamine with pentafluorobenzaldehyde at room temperature without prior extraction of the drug from plasma. The derivative, pentafluorophenyloxazolidine, is readily extracted from plasma into a small volume of hexane. Samples usually can be injected directly into the gas chromatograph without concentration of the hexane solution. Data are presented to illustrate the suitability of the method for dosage form bioavailability evaluation from plasma phenylpropanolamine levels achieved after acute oral administration of a typical dosage form.


Interpretation of distribution coefficients of p-alkylpyridines by a modified regular solution theory.

The hypothetical hexadecane-octane distribution coefficients for the alkylpyridines were deduced from the corresponding oil-water distribution data. The values were analyzed by a modified regular solution theory. A good correlation was noted by including the Flory-Huggins entropy factor in the calculation and by considering the deviation from the geometric mean assumption.


Reduction of activity of cyanocobalamin in the presence of methylparaben sodium at autoclave temperature.

Reduction of activity of cyanocobalamin (vitamin B12) due to degradation or interaction with methylparaben sodium was measured by UV spectrophotometry and microbial assay. TLC of the heated mixture showed two different spots, which indicate some alteration in the structure of the cyanocobalamin molecule in the presence of methylparaben sodium at 115 degrees for 10 min. The losses were about 20% by UV measurements and 32% by microbial assay. The degree of loss was sufficient to suggest that methylparaben sodium might have considerable influence on the stability of pharmaceutical products containing cyanocobalamin. Methylparaben and sodium chloride had no effect on cyanocobalamin.


Enhancement of solubility of drug salts by hydrophilic counterions: properties of organic salts of an antimalarial drug.

Judicious choice of the salt form of a drug can greatly affect the aqueous solubility and formulation of the compound. The objective of this work was to demonstrate the effect of various counteranions on the aqueous solubility of the antimalarial agent alpha-(2-piperidyl)-3, 6-bis(trifluoromethyl)-9-phenanthrenemethanol. Several organic salts of this drug were studied. The methods of synthesis, the apparent aqueous solubilities, and in vitro dissolution tests for these salts are reported. The lactate salt was 200 times as soluble as the hydrochloride salt. This enhanced solubility suggests that parenteral administration of this drug may now be feasible.


Errors involved in instantaneous intravascular input assumptions.

A comparative evaluation of a zero-order input and the generally accepted instantaneous intravascular input assumption is made for two- and three-compartment open model systems. Equations are derived and a nomogram is prepared to calculate the magnitude of error involved in instantaneous input assumptions. It is suggested that all intravascular administrations be considered as zero-order inputs.


Correlations between substituent parameters of 4-substituted benzoic acids and their in vitro dissolution and partitioning.

The in vitro dissolution and partitioning of some 4-substituted benzoic acids from nondisintegrating disks was investigated using a water-octanol system. The rates of appearance of benzoic acids in the aqueous phase differed from the rates of appearance in octanol, probably due to back-transfer from the octanol phase. The suitability of the procedure for investigating the influence of molecular modification on in vitro dissolution and partitioning is considered. Correlations among the rates of appearance in octanol, the rates of appearance in an aqueous phase, and substituent parameters of benzoic acids were investigated. The best statistical fit was obtained using molecular orbital substituent indexes.


Sinoacutine from Glaucium contortuplicatum Boiss.

A phytochemical investigation of Glaucium contortuplicatum Boiss. (Papaveraceae) resulted in the isolation of sinoacutine from this plant for the first time. Spectral evidence for the identity of the isolated compound as sinoacutine is presented.


Antihemolytic and antiproteolytic properties of substituted thiosemicarbazidophenothiazines and thiazolidonylphenothiazines.

Antihemolytic and antiproteolytic properties of several 10-(1-acetyl-4-arylthiosemicarbazido) phenothiazines and their corresponding cyclized 10-(2-arylimino-3-acetylamino-4-thiazolidonyl) phenothiazines were investigated. In vitro protection of hypoosmotic hemolysis of human red blood cells by substituted thiosemicarbazidophenothiazines and substituted thiazolidonyl-phenothiazines was concentration dependent; the degree of protection ranged from 19 to 32 and 26 to 42%, respectively, at a final concentration of 0.1 mM. All phenothiazines exhibited antiproteolytic activity. The in vitro inhibition of trypsin-induced hydrolysis of bovine serum albumin by these phenothiazines was concentration dependent and competitive in nature; the degree of inhibition ranged from 30 to 50 and 32 to 79% for substituted thiosemicarbazidophenothiazines and substituted thiazolidonlyphenothiazines, respectively, at a concentration of 1mM. Cyclization of substituted thiosemicarbazidophenothiazines into the corresponding cyclized substitited thiazolidonlyphenothiazines increased the antihemolytic and antiproteolytic effectiveness of these phenothiazines.


Fluorometric determination of cephradine in plasma.

A fluorometric method was developed for the determination of cephradine in plasma. A fluorescent product is formed when samples of deproteinized plasma containing cephradine are heated for 3 hr at 100 degrees and pH 1. The fluorescence is determined in sodium hydroxide solution (pH 13.5) at excitation and emission wavelengths of 350 and 445 nm, respectively. Only 0.1 ml of plasma is required, and concentrations of cephradine as small as 0.1 mug/ml may be determined. In plasma samples from a dog taken over a 10-hr period after an intramuscular injection of 250 mg of cephradine, essentially similar concentrations of cephradine were obtained by the fluorometric method and a standard microbiological bioassay.


Comparison of several molecular topological indexes with molecular surface area in aqueous solubility estimation.

The molecular topological indexes proposed by Wiener (Wiener number), Hosoya (Z-value), and Randic (branching index) were corelated with computed molecular surface areas and aqueous solubilities for the monofunctional aliphatic alcohols, ethers, ketones, aldehydes, carboxylic acids, esters, and hydrocarbons. Comparison of the indexes with molecular surface area indicates that all three indexes (or simple modifications) correlate with molecular surface area and, although computed in different manners, reflect molecular topology. Comparison of the correlations of log solubility with the several indexes leads to the following conclusions: (a) the branching index works well for aliphatic, acyclic monofunctional compounds but not cyclic aliphatic compounds; (b) the square root of the Wiener number correlates less satisfactorily with log solubility than the other indexes but more correctly handles cyclic compounds (when generalized after Hosoya); (c) correlations of log solubility with the log Z-value are satisfactory, but the index is difficult to compute; and (d) the molecular surface are represents the single best parameter with which to correlate and estimate aqueous solubility due to its generality. However, for a restricted series of compounds, the branching index is perhaps the most useful index by virtue of its simplicity.


Isolation of 10, 11-epoxide of protriptyline in rat urine after protriptyline administration.

The 10, 11-epoxide, 10-hydroxy, and 10, 11-dihydrodiol metabolites of protriptyline were identified in rat urine collected after the administration of 40 mg/kg ip of protriptyline. Mass spectrometric characterization confirmed the structure of these metabolites.


Identification of 10, 11-epoxide and other cyclobenzaprine metabolites isolated from rat urine.

Cyclobenzaprine (40 mg/kg ip) was administered to rats, and six urinary metabolites of this drug were identified. They were the 10, 11-epoxide, the N -oxide, the desmethyl derivative, the hydroxylated and desmethylhydroxylated compounds, and the N-oxide hydroxylated at the 10- or 11-position. Mass spectrometric analysis confirmed their structures.


Influence of route of administration on physiological availability of levodopa in dogs.

The physiological basis for the reduced levodopa bioavailability following oral administration was investigated. Four dogs received single 25-mg/kg doses of 14C-levodopa on three separate occasions in a crossover fashion via hepatoportal catheter, intravenous, and oral administrations. Plasma and urine specimens were analyzed for intact levodopa and total radioactivity. The ratios of areas under the plasma concentration-time curves following hepatoportal and intravenous adminstrations were close to unity, and the shapes of the curves were virtually identical. Following oral administration, however, significant reductions in the areas under the plasma concentration-time curves were observed. These data indicate that the physiologically impaired bioavailability of orally administered levodopa occurs almost exclusively as a result of metabolic degradation within the GI lumen and/or gut wall.


Rheological evaluation of hog gastric mucin as a model mucus system.

The rheological evaluation of preparations containing 10, 15, 20, and 25% powdered hog gastric mucin was carried out over the 13-48 degrees temperature range using rotational and creep viscometry. The preparations were almost viscous, and no elastic behavior was demonstrated. The addition of borate ions frequently produced a slight decrease in viscosity. Tetracycline hydrochloride decreased the viscosity of the 10 and 25% materials, although the addition of this compound to fresh gastric and bronchial mucous gels markedly increased viscosity. The model is, therefore, only suitable in limited circumstances as a basis for the evaluation of the effect of drugs on gastric mucus.


Absorption and  distribution of radioactivity from suppositories containing 3H-benzocaine in rats.

The effects of the suppository vehicle, drug concentration, and nonionic surfactants on in vitro benzocaine dialysis through a cellulose membrane and on rectal absorption in rats of total radioactivity following administration of 3H-benzocaine were investigated. In vitro dialysis correlated quite well with in vivo absorption, and drug release was greater from water-soluble vehicles than from oleaginous vehicles. Inclusion of a nonionic hydrophilic or lipophilic surfactant in cocoa butter resulted in a statistically significant increase for in vitro drug release, while a lipophilic surfactant showed little effect in vivo and a hydrophilic surfactant depressed release in vivo. Both types of surfactant had small effects on release from polyethylene glycol. In vitro release of benzocaine from some commercially available suppositories was compared with experimental preparations. Variation in blood radioactivity following administration of the same concentration of 3H-benzocaine in the same dosage  form in male and female rats is reported.


Attainment of highly uniform solid drug dispersions employing molecular scale drug entrapment in polymeric latices.

The uniformity of distribution attainable for an amine drug in solid dispersions prepared using a molecular scale entrapment procedure was investigated. Excellent reproducibility of drug content throughout the entire entrapment product was demonstrated in both flocculated (high drug levels) and deflocculated (low drug levels) systems. Drug content and content uniformity were found to be predictable for deflocculated systems, even at high drug dilution ratios. Milling or particle-size fractionation appeared to have no effect on the distribution of drug throughout the solid dispersion entrapment products. Dry blending was inferior to molecular scale drug entrapment in distributing small quantities of drug uniformly.


Contact angles and wetting of pharmaceutical powders.

Contact angles of pharmaceutical powders were determined by the h-epsilon method, which consists essentially of measuring the maximum height of a drop of liquid fomed on a presaturated compact of the material. Determinations with aspirin as the test material indicate that the measured value is independent of the particle size of the powder and the porosity of the cake. The method was extended to include determinations on mixed powder systems. The results show that the hydrophobic material dominates with large particle-size powders; with small particle sizes, a linear relationship between the cosine of the contact angle of the mixed system and the proportion of the components is obtained. Results are presented for a wide variety of materials of pharmaceutical interest.


In vivo and in vitro evaluation of a microencapsulated narcotic antagonist.

Injectable microcapsules containing 75% (w/w) cyclazocine, a narcotic antagonist, were prepared with dl-poly(lactic acid) as the coating material. Capsule fractions falling between 105 and 295 mum released about 90% of their cyclazocine in 8 days of rotating-bottle extraction at 37 degrees in pH 7.4 phosphate buffer. Although larger capsules released the drug somewhat more slowly, all capsules released cyclazocine far more rapidly than an ideal capsule should. This rapid release is attributed to macroscopic defects located in the capsule walls. The ability of the capsules to block the action of morphine in vivo was assessed by injection of a sesame seed oil suspension into Holtzman rats. A hot-plate test procedure was used to evaluate animal behavior. Capsule doses of 100-250 mg/kg to rats caused significant antagonism of morphine's analgesic effect for 14 days after injection. By Day 17, no antagonism occurred, indicating that the capsules completely released the drug in vivo between 14 and 17 days after injection.


Molecular orbital calculations for parabens: a  possible mechanism of action.

Molecular orbital calculations were carried out on the series benzoic acid, p-hydroxybenzoic acid, methylparaben, and ethylparaben. The characteristic trends of this entire series of preservatives are demonstrated by these members. The computer program  used was Iterated Extended Hückel Theory. These systems were characterized in terms of atomic charge distributions, effect of hydroxyl and ester groups (both sterically and electronically), preferred molecular conformations, and  distinguishing features of molecular orbitals. Through this approach, it was hoped that a common mode of action for all members of this series could be detected and that the trend(s) in this feature would correlate with known trends in activity of members of this series.


Rapid determination of theophylline in human plasma by high-pressure liquid chromatography.

A rapid, specific, high-pressure liquid chromatographic method for the determination of theophylline in plasma was developed. The procedure is fast enough (21 min from receipt of blood to reporting value) to be used for emergency determinations. The sensitivity, precision, and accuracy are sufficient for  routine monitoring of therapeutic levels in patients. The assay is specific enough to be valid in the presence of caffeine and theobromine. Metabolites of theophylline as well as a number of drugs do not interfere with the assay.


Interaction of dantrolene sodium with human serum albumin.

The binding of dantrolene sodium to human serum albumin was studied by fluorescence quenching and difference spectrophotometry. The association constant was calculated from each method of measurement and was large. This binding affinity may be of importance in the clinical setting, since competitive displacement of anionic drug by concurrently administered agents can occur. Consequently, the displacement of dantrolene from albumin was examined with a wide range of drugs. To gain insight into the characteristics of drug-albumin binding, the interaction of drug with cationic, anionic, and nonionic surfactants was also studied. Additions of drug to solutions of either the anionic or nonionic surfactant failed to result in a perturbation with the difference spectral technique. However, dantrolene added to the cationic resin produced a difference spectrum analogous to that observed with the drug-protein interaction.


Identification and quantitative GLC determination of iproniazid in human urine.

A GLC method for the specific identification and quantitation of iproiazid, a potent monamine oxidase inhibitor drug, is described. The free drug isolated from urine samples by two-phase extraction reinforced with salting out. Identification and quantitative determination at the microgram level are done on aliquots of the chloroform extract by GLC, using the 2-butyl analog as an internal standard. Iproniazid and potentially interfering compounds present in the extracts are also identified by GLC-mass spectrometry and TLC for supporting evidence of the GLC method's specificity.


Solubilization as a method for studying self-association: solubility of naphthalene in the bile salt sodium cholate and the complex pattern of its aggregation.

Solubilization of uncharged, slightly soluble solutes is shown to be a useful approach for investigating patterns of self-association. The solubility of naphthalene in aqueous solutions of sodium cholate was determined over the concentration range of 0-0.20 mole/liter at 25 degrees. Bile salts such as sodium cholate have many detergent-like properties and exhibit hydrophobic self-association in aqueous solutions. It has become cutomary to describe this aggregation using the model of micelle formation. The naphthalene solubility data show that the CMC for sodium cholate is not well defined. Comparison with solubilization in a typical micelle-forming system, sodium decanesulfonate, shows clearly that sodium cholate does not resemble a micelle-forming system. Further examination of the solubility data in terms of mutual association of naphthalene with aggregate species shows that the self-association of sodium cholate is not consistent with the formation of (a) only large micelles containing 10 or more monomers, (b) only dimers, (c) dimers and large micelles, and (d) any unique oligomer or multimer. A complex pattern of association, including the formation of dimers and one or more higher oligomers, is indicated.


Interactions of nucleic acid bases with catechol: UV studies.

UV absorption studies on weak interactions of adenine, cytosine, thymine, and uracil with cathechol in aqueous solutions containing 0.1 N HCl gave evidence for the formation of charge transfer complexes. The absorptions of these complexes were found in the UV region at longer wavelengths than those of the pure components. It was possible to calculate various thermodynamic parameters and molar extinction coefficients at different wavelengths. The biological significance of the results is discussed.


In vitro adsorption of various pharmaceutical to montmorillonite.

Dissolution and dialysis studies showed that cationic drugs and certain nonionic drugs bind strongly to montmorillonite clay. The quantity of drug bound by one unit of clay varied considerably. Anionic drugs were weakly bound, and less bioavailabilty problems would be anticipated with these medicinals. The mechanism of binding of cationic drugs to montmorillonite was proposed as a two-step process: a cation-exchange reaction followed by strong surface chemisorption.


Alpha-and beta-halomorphides: stereochemistry, analgesic potency, toxicity, and interaction with narcotic receptors in vitro.

The configuration of the halogen on  the C-ring of several alpha- and beta-halomorphides was determined by NMR. The analgesic potencies of these halomorphides and their interactions with narcotic receptors in a rat brain homogenate were measured, as was the toxicity of the alpha- and beta-chloromorphides. The halomorphides were examined as possible irreversible binders to the narcotic receptor.


Partition coefficients of selected pyridine carbamates and comparisons with their acetylcholinesterase and butyrylcholinesterase inhibitory potencies.

Partition coefficients of a series of 2-substituted 3-(N,N-dimethyl)carbamyloxypyridines were determined in an octanol-buffer (pH 7.4) system. The values obtained were compared with the ihnibitory potencies of acetylcholinesterase and butyrylcholinesterase. No significant difference was found for the role of hydrophobicity in the two enzyme systems.


Pharmacology of malnutrition III: binding of digoxin to normal and kwashiorkor serum.

Digoxin binding to normal and kwashiorkor serum was studied and found to be inferior in the latter. Digoxin should be used with care in hypoalbuminemic patients.


Antileukemic and other constituents of Tithonia tagitiflora Desf.

Phytochemical investigation of Tithonia tagitiflora has led to isolation of six new germacranolides, tagitinins A, B, C, D, E, AND F, beta-sitosterol, and its beta-D-glucoside. Among these, tagitinin F possesses  antileukemic activity.


Conformationally defined adrenergic agents I: potentiation of levarterenol in rat vas deferens by endo- and exo- 2- aminobenzobicyclo[2.2.2]octenes, conformationally defined analogs of amphetamine.

Four conformationally defined analogs of amphetamine were synthesized and studied for their ability to potentiate the action of levarterenol on the isolated vas deferens from reserpine-treated rats. The compunds also were studied for indirect adrenergic agonist activity in the same test system. A definite stereochemical correlation was demonstrated in each case, the exo-isomers being considerably more active than their endo-counterparts both in potentiation and in indirect activity. The more active isomers of each pair correspond to an anti-periplanar conformation of amphetamine. The compounds are probably acting by inhibition of the neuronal amine uptake mechanism, since none of the compounds was a direct-acting agonist itself. These results are discussed in relationship to other previously reported, conformationally defined, amphetamine analogs.


Major alkaloids of Glaucium flavum Grantz, population Ghom.

Glaucium flavum Grantz, population Ghom, contains 1.24% dicentrine, 0.89% bulbocapnine, and 0.05% salutaridine in dry aerial parts and root of the flowering plant. These alkaloids were detected for the first time in the Glaucium genus.


Simultaneous quantitative GLC determination of chlorpheniramine maleate and phenylpropanolamine hydrochloride in a cold tablet preparation.

A GLC method was developed for the simultaneous determinations of chlorpheniramine maleate and phenylpropanolamine hydrocholride in a cold tablet preparation containing a large amount of aspirin. The method utilizes a solid sampling device to eliminate interference from solvent, and it is rapid and precise. The total analysis time is less than 1.5 hr, thereby permitting its use for quality control purposes.


GLC analysis of lidocaine in plasma using a novel nitrogen-sensitive detector.

A simple, rapid GLC method for the determination of therapeutic levels of lidocaine in plasma or blood is described. After extraction with benzene from alkalinized plasma, the compound is analyzed by GLC using a nitrogen-sensitive detector. Quantitation is accomplished using an internal standard and a standard curve, which was linear over the 0.1-10-mug range. The limit of detection was approximately 10 ng/ml. Recovery of the parent compound was essentially quantitative. Plasma data are presented to demonstrate the utility of the method.


Synthesis and activity of (R)-(-)-m-trimethylacetoxy-alpha-[(methylamino)methyl]benzyl alcohol hydrochloride: a prodrug form of (R)-(-)-phenylephrine.

Optically pure (R)-(-)-m-trimethylacetoxy-alpha-[(methylamino)methyl]benzyl alcohol hydrochloride was synthesized by the following sequence: (R)-(-)-phenylephrine was condensed with acetone in the presence of calcium carbide to give an oxazolidine derivative and then treated with thallous ethoxide in ether followed by trimethylacetyl chloride to yield the phenolic ester. Finally, the oxazolidine ring was cleaved by one equivalent of hydrogen chloride in ethanol. Condensation of phenylephrine with benzaldehyde, with or without solvents, gave either 1,1,2-trimethyl-4,6-dihydroxy-1,2,3,4-tetrahydroisoquinoline or a mixture of side-chain oxazolidine and the tetrahydroisoquinoline. Condensation of epinephrine with opianic acid in pyridine also gave a tetrahydroisoquinoline only. When applied on rabbit eyes, the prodrug (R)-(-)-m-trimethylacetoxy-alpha[(methylamino)methyl]benzyl alcohol hydrochloride exhibited an unexpected, three times higher mydriatic activity than the corresponding racemic prodrug and was 15 times more active than the parent, (R)-(-)-phenylephrine.


Systematic assessment of tolerance to pentobarbital by pellet implantation.

Rapid tolerance development to pentobarbital by pentobarbital pellet implantation was evidenced by a decrease in sleeping time after challenge with different doses of sodium pentobarbital ranging from 37.5 to 100 mg/kg i.p. or a fixed dose of 75 mg/kg i.p. of the drug. The sleeping time produced by sodium pentobarbital decreased by 50% after 1 day. After 2 or 3 days of implantation, the sleeping time was generally further decreased to 15 to 20% of the placebo control group. Tolerance to pentobarbital was still evident 72 hours after pellet removal. The tolerance development to pentobarbital by pentobarbital pellet implantation also was demonstrated by other pentobarbital-induced responses such as hypothermia and lethality. In mice implanted with a 75-mg pentobarbital pellet for 3 days, the degree and duration of pentobarbital-induced hypothermia by intraperitoneal or intracerebral administration of the drug was attenuated. The chronic administration of pentobarbital by three days of pellet implantation reduced the effect of sodium pentobarbital on lethality as evidenced by an increase in the LD50 of sodium pentobarbital after intraperitoneal or intracerebral administration of the drug.


Human sedative self-administration: effects of interingestion interval and dose.

In a residential hospital ward setting, either sodium pentobarbital, diazepam or ethanol was made availabe for oral ingestion to volunteer human subjects with documented histories of drug abuse. During specified portions of the day, tokens could be earned by riding an exercise bicycle and exchanged for doses of a drug. Increases in the required minimum interingestion interval from 0 to 30 minutes produced decreases in the number of ingestions of sodium pentobarbital and diazepam. In another experiment, increases in the dose per ingestion (30-90 mg of sodium pentobarbital, 2-10 mg of diazepam, or 1.86-11.14 g of ethanol) produced increases in the number of ingestions. In both experiments, the effects of the manipulated variable were similar for all of the drugs studied. The study demonstrates the feasibility of human self-administration research with the sedative drugs, sodium pentobarbital and diazepam, for which substantive experimental data have not previously been reported. In addition, the results indicate that both dose and minimum interingestion interval bear a systematic controlling relationship to the occurrence of drug self-administration behavior.


Prenatal administration of morphine to the rat: tolerance to the analgesic effect of morphine in the offspring.

The analgesic activity of morphine was assessed by the hot-plate technique in the offspring of female CFE rats that had received morphine twice daily on days 5 to 12 of pregnancy. A dose of 5.0 mg/kg of morphine was administered for the first 3 injections; 10 mg/kg was used for each of the remaining 13. Morphine dose-response curves were determined in the offspring at 5 weeks of age. The analgesic effect of morphine in the offspring of morphine-treated females (morphine offspring) was attenuated by as much as 50% compared to the offspring of saline-treated females (saline offspring). This same relationship between the morphine and saline offspring was also observed in offspring rendered tolerant to the analgesic effect of morphine. A diminished analgesia in the morphine offspring compared to the saline offspring was also observed after the injection of graded doeses of levorphanol in both nontolerant and morphine-tolerant offspring. The analgesic effect of a single dose of morphine was also attenuated in 3-, 5- and 11-week-old morphine offspring. No differences were found in either brain or plasma concentration of morphine between the morphine and saline offspring. The long-term effect of prenatal morphine administration could not be explained on the basis of maternal influences since cross-fostering procedures failed to abolish it. It is concluded that the administration of moderate doses of morphine to gestating rats can induce a long-lasting tolerance to the analgesic effect of morphine in the offspring.


Influence of nonsteroidal anti-inflammatory agents on myocardial ischemia in the cat.

Indomethacin, meclofenamic acid and acetylsalicylic acid are prostaglandin synthetase-inhibiting, nonsteroidal anti-inflammatory drugs. Their effects on hemodynamic and enzymatic responses to coronary artery occlusion were evaluated in the cat. The direct effects of these drugs on isolated tissue preparations (i.e., cat papillary muscle, aortic strip and liver lysosomes) were also studied. None of the drugs tested exhibited any significant hemodynamic or biochemical effects which would indicate protection against damage due to myocardial ischemia during the 5-hour experimental period. Furthermore, only indomethacin produced significant effects on the isolated tissues studied. Indomethacin increased the tension of aortic strips confirming a pressor effect seen in the intact animal and exerted a modest stabilization of isolated liver lysosomes. All three anti-inflammatory drugs inhibited prostaglandin F2alpha, release in heart homogenates by 82 to 87%. It is concluded that nonsteroidal anti-inflammatory drugs do not significantly influence the early course of myocardial ischemia in the cat, in contrast to the previously reported preservation of myocardial integrity afforded by dexamethasone and methylprednisolone.


Effects of therapeutic concentrations of diphenylhydantoin on transmembrane potentials of normal and depressed Purkinje fibers.

Standard intracellular microelectrode techniques were used to study canine Purkinje fibers (PF) which had been superfused with blood or Tyrode's solution to determine the cardiac cellular electrophysiologic changes induced by antiarrhythmic concentrations of diphenylhydantoin (DPH). Some PF were normal whereas others were depressed by stretch, exposure to ouabain (125 mug/1) or superfusion with a solution in which all Na+ was replaced by tetraethylammonium. For normal fibers, therapeutic concentrations of DPH (DPH) induced slight decreases in action potential (AP) amplitude, maximum upstroke velocity of phase O (Vmax) and membrane responsiveness and somewhat greater decreases in AP duration. For fibers moderately depressed by ouabain or stretch, with reduced AP amplitude, maximum diastolic potential and Vmax, therapeutic [DPH] increased these variables. Fibers markedly depressed by Na-free solution or stretch developed slow response AP. The amplitude and Vmax of the AP were decreased by therapeutic [DPH]. Therapeutic [DPH] also suppressed automaticity and ouabain-induced delayed afterdepolarizations. Our studies suggest that the slight depression of normal PF AP characteristics induced by therapeutic [DPH] probably is of little significance with respect to antiarrhythmic effect. In contrast, both the improvement of AP characteristics of moderately depressed fibers and further depression of severely depressed fibers caused by [DPH] might modify arrhythmias. Effects of DPH on automaticity and delayed afterdepolarizations also would contribute to its antiarrhythmic effect.


Effect of quinidine on cation exchange in cultured cells.

The effects of quinidine on membrane ion exchange were examined using monolayer cultures of mammalian cells. Quinidine, in concentrations from 10(-6) to 10(-3) M, produced a prompt inhibition of the passive Na influx, dose-dependent along a sigmoid log dose-response curve. This effect was at a maximum for each concentration of the drug within 30 seconds of application. Passive Na influx (pmol/cm2/sec) decreased from 18.8 to 17.6 (P less than .05) and 10.5 (P less than .001) in the presence of 10(-6) and 10(-3) M quinidine, respectively. In the continued presence of quinidine, there was no further time-dependent effect on the Na influx, nor was there any tendency for the influx to recover. Washing the cells free of quinidine, however, resulted in a return of Na influx to control levels within 1 to 3 minutes. After 1 to 2 minute of quinidine treatment, coupled active Na efflux/K influx rapidly declined, reaching minimum values for each concentration between 2 to 4 minutes of drug treatment. Beyond that time, active Na/K fluxes again increased, but to values which remained significantly less than control, for up to 4 hours. Ten minutes of exposure to quinidine were required before any demonstrable effect on the passive K efflux could be recorded. In the presence of quinidine, there was reduced membrane turnover of both Na and K, but such that after a brief initial period (10 minutes or less) both ions were in flux equilibrium, explaining the absence of change in [Nai] and [Ki] in the presence of quinidine. Calculations of Ec1 indicated that, when present for 4 hours, quinidine did not change the Em in these cells although significant (P less than .001) reductions in apparent PNa and Pk values were recorded. The effect on PNa was much greater than that on Pk. The quinidine-induced flux changes occurred in a definite temporal sequence suggesting that they could all be explained on the basis of one direct initial action. This initial direct action, namely the prompt reduction in Na influx, by modifying Na pump activity, could lead to a decreased K efflux, secondary to the depressed Na-coupled active K influx via the Na pump.


Studies of a transplantable rat pheochromocytoma: biochemical characterization and catecholamine secretion.

The biochemistry and secretory characteristics of a transplantable rat pheochromocytoma have been studied. This tumor possesses the enzyme required for the biosynthesis of norepinephrine from tyrosine, and stores large amounts of norepinephrine (33 +/- 3 nmol/mg of protein). The tumor does not have detectable levels of noradrenalin N-methyltransferase, nor does it contain significant amounts of epinephrine. Approximately two-thirds of the catecholamine content, and one-half of the dopamine beta-monoxygenase activity in the tumor can be isolated in a granule fraction by sedimentation. This granule fraction also contains ATP; the molar ratio of catecholamine to ATP in this granule fraction (5.6 +/- 0.9) is similar to that found in granules prepared from normal adrenal glands. Cell suspensions were prepared by mechanical disruption of the tumor. Incubation of these cell suspensions in media containing 56 mM K+, or the divalant cation ionophores, lasolocid or A23187, leads to the release of catecholamine from these cells. The cells do not secrete catecholamine in response to acetycholine. Catecholamine release induced by 56 mM K+ appears to be by exocytosis, since this release is dependent upon extracellular Ca++, and is accompanied by the release of dopamine beta-monooxygenase, but not of lactate dehydrogenase, from the cells. The mechanism by which the ionophores stimulate catecholamine secretion has not been established.


Interactions between local anesthetics and spasmogens on the guinea-pig ileum.

The effect of various local anesthetics and other substances known to modify calcium fluxes in cells, on submaximal responses of guinea-pig ileum to substance P, acetylcholine, histamine and barium chloride was determined. Procaine caused a dose-related depression of the response to all the agonists but the response to substance P was far less susceptible to this depression. Lidocaine, bupivacaine, pramoxine and W 6211 also caused a lower degree of attenuation of the response to substance P than the responses to acetylcholine, histamine and barium chloride. Verapamil caused a dose-related depression of responses to all the agonists equally. The use of calcium-free solutions abolished responses to substance P, acetylcholine and histamine. The response to barium chloride was less affected by calcium withdrawal but was reduced markedly. In the presence of 10 mM lanthanum chloride, the response to all the agonists was abolished. The relative resistance of the substance P responses to antagonism by local anesthetics suggests that different and more efficient channels for calcium entry into the smooth muscle cell are involved.


An analysis of the subsynaptic site of action of theophylline on isolated cat tenuissimus muscle.

The subsynaptic actions of theophylline were studied by employing intracellular recording techniques in the isolated cat tenuissimus muscle. Theophylline produced a dose-dependent increase in miniature end-plate potential (MEPP) amplitude. The maximal increase (30%) in MEPP amplitude occurred at the 1.8 mM concentration of theophylline with a concomitant depolarization of the resting membrane potential. Depolarizations induced by acetylcholine were potentiated by 1.8 mM theophylline. This effect was less evident with a carbachol-induced depolarization, which indicates a possible anticholinesterase action. Input resistance decreased significantly; this effect correlated with the decline in resting membrane potential produced by theophylline. The equilibrium potential of the EPP was shifted to a more positive value in a reversible manner. In addition, the conductance change due to MEPPs, acetylcholine and carbachol was increased by theophylline treatment. These results suggest that the shift in equilibrium potential of the EPP coupled with a slight anticholinesterase action may account for the increase in MEPP amplitude observed with theophylline treatment.


Histamine-induced lipid mobilization in humans and dogs.

The effect of histamine on serum free fatty acid (FFA) and glycerol levels was examined in humans and dogs in vivo. By the end of a 15-minute infusion of histamine diphosphate (11 mug of histamine per min i.v.), FFA levels in six male human volunteers had risen from basal values of 424 +/- 41 (mean +/- S.E.M.) to 909 +/- 45 muEq/1, and glycerol levels had risen from 66 +/- 5.5 to 124 +/- 9.3 mumol/1. These effects in man were not blocked by diphenhydramine, an H1-receptor antagonist, but were entirely blocked by propranolol, a beta adrenergic antagonist. Similar infusions of histamine (11 mug/min i.v.) in six anesthetized dogs caused FFA levels to rise from 189 +/- 13 to 461 +/- 92 muEq/1 and glycerol levels to rise from 58 +/- 3.7 to 157 +/- 22.4 mumol/1. These effects in the dog were not blocked by diphenhydramine or by propranolol but were entirely blocked by metiamide, an H2-receptor antagonist. These observations illustrate that low levels of histamine in vivo can produce significant elevations of serum FFA and glycerol levels in both humans and dogs. These results further suggest that the action of histamine in humans is indirect whereas the effect in dogs may be due to a direct action of histamine at the H2-receptor in canine adipose tissue.


The elimination of ethyl, n-propyl, n-butyl and iso-amyl alcohols by the isolated perfused rat liver.

The elimination of ethyl, n-propyl, n-butyl and iso-amyl alcohols has been investigated over a dose range in the isolated perfused rat liver. The elimination of ethanol was saturable with a zero-order phase being succeeded below a concentration of 5 mmol by an exponential phase. The elimination of n-propyl, n-butyl and iso-amyl alcohols was similar. There was an increasing affinity of the alcohol to the rate-limiting process with increasing carbon chain length of the alcohol. The apparent Michaelis constants for the alcohols were similar to those determined in vitro with the enzyme alcohol dehydrogenase. The addition of ethanol simultaneously with either n-propyl, n-butyl or iso-amyl alcohol was associated with a reduction in the rate of elimination of both ethanol and the higher alcohol. Changes in the apparent Michaelis constant (KM) in the absence of changes in the apparent maximal velocity (Vmax) suggested competitive inhibition for the elimination process.


A comparative diuretic and tissue distribution study of bumetanide and furosemide in the dog.

Intravenous dose-response data obtained from renal clearance studies in anesthetized dogs indicated that bumetanide was approximately 30-fold more potent than furosemide in enhancing sodium excretion. After the administration of 0.01 mg/kg of bumetanide or 1.0 mg/kg of furosemide, the relationship between i.v. diuretic activity and tissue distribution was evaluated. In dog renal clearance experiments, bumetanide and furosemide significantly enhanced urine flow, sodium and potassium excretion. Inulin clearance as an estimate of glomerular filtration rate was not altered by either drug, but sodium reabsorption was decreased with bumetanide (13%) and furosemide (12%). At these diuretic doses, both compounds were bound to dog plasma protein to about the same extent (86-91%), although total plasma levels were 100-fold higher for furosemide. Within 1/2 hour after the i.v. administration of 14C-bumetanide or 14C-furosemide, 86 to 99% of the 14C in urine, plasma, kidney, and liver appeared as unchanged drug. One minute after maximal diuresis bumetanide was found to have a higher affinity (3-fold) for kidney compared to furosemide. These data offer a possible explanation for the i.v. diuretic potency difference between these two compounds. Furthermore, the lack of significant difference in plasma protein binding and the absence of urinary metabolites of either drug suggest that other factors may also contribute to the marked differences in diuretic activity between bumetanide and furosemide.


Inactivation of neural and exogenous norepinephrine in rat tail artery studied by the oil immersion technique.

The inactivation of exogenous and neural norepinephrine (NE) by helical strips of rat tail artery was studied with a combination of the techniques of transmural stimulation and oil immersion. A steady-state contraction was elicited either by adding low concentrations of NE to the bath or by low frequency transmural stimulation. The aqueous bath solution was then replaced with mineral oil and relaxation was monitored. A prolongation of the rate of relaxation of the strip at a given concentration of exogenous NE or frequency of transmural stimulation indicates that inactivation of NE has been slowed. The major known processes for inactivation of NE were inhibited by pharmacological agents used singly or in various combinations (uptake by cocaine, uptake by corticosterone, catechol-O-methyltransferase by tropolone and monoamine oxidase by iproniazid). Cocaine was the only agent which alone caused a marked shift in the relaxation curve. A modest and equivocal effect on relaxation after inhibition of extraneuronal uptake (uptake), or catabolism of NE (catechol-O-methyltransferase and monoamine oxidase) was only demonstrated under special circumstances (high concentrations of NE, combinations of inhibitors, or uptake simultaneously inhibited). The data suggest that low concentrations of NE, both exogenous and neural, are preferentially inactivated in rat tail artery by neuronal uptake and storage.


Differential effects of nerve impulses on adrenergic storage vesicles in rat heart.

The effects of increasing and decreasing activity in sympathetic neurons on light (D420 = 1.05) and heavy (D420 = 1.15) populations of adrenergic vesicles have been determined. Norepinephrine (NE) was used as a marker for the soluble contents of the vesicles, and dopamine beta-hydroxylase was used as a marker for the vesicle membranes. Cold exposure was used to increase activity in the sympathetic nervous system. A 40% decrease in the NE content of the rat heart with no change in the activity of dopamine beta-hydroxylase was observed after 70 minutes at 5 degrees C. The fall in NE content was completely blocked by pretreating the animals with chlorisondamine. Separation of light and heavy populations of vesicles was achieved with linear sucrose density gradients. Cold stress of 70 minutes duration led to a marked decrease in the NE content of the light vesicles. Blocking adrenergic nerve impulses with chlorisondamine resulted in an increase in total NE in the heart but had no effect on dopamine beta-hydroxylase activity. The initial effect of chlorisondamine was to increase the NE content of the light vesicles. The administration of alpha-methyl-p-tyrosine for 6 hours caused an approximately equal loss of NE from both vesicle populations. The decrease in total heart NE was about 25% and could be prevented by pretreating the animals with chlorisondamine. These results suggest that the light vesicle fraction is involved in the rapid or short-term responses to changes in nerve impulse frequency. Changes in the NE content of the heavy vesicles in rat heart were seen only after longer times, suggesting that these particles may function only as auxiliary storage sites for the neurotransmitter.


Coincidence of blockade of synaptosomal 5-hydroxytryptamine uptake and decrease in tryptophan hydroxylase activity: effects of fenfluramine.

A single injection of fenfluramine hydrochloride resulted in a short-term increase in striate synaptosomal conversion of tryptophan to serotonin (5-HT) in rat brain. In contrast, D- and L-amphetamine sulfate resulted in a short-term decrease of this index of 5-HT biosynthesis. None of the amphetamines studied altered the kinetics of synaptosomal uptake of L-[3-14C]-tryptophan measured in the same striate preparation. Within 4 hours after fenfluramine administration, 3H-5-HT uptake into synaptosomes was markedly decreased; it returned to control levels in 10 to 14 days. Intrasynaptosomal tryptophan hydroxylase activity dropped markedly within 4 hours of drug administration and remained depressed for 10 to 14 days, its return to control levels coinciding with that of 3H-5-HT uptake. Only 5-HT cell body enzyme prepared from the lateral midbrain (B9) demonstrated a reduction in activity comparable to that seen in the synaptosomes; very small decreases occurred in cell body enzyme prepared from whole midbrain (B7, B8, B9) or medial midbrain (B7, B8). Lateral midbrain tryptophan hydroxylase activity returned to control levels by 8 days. In vitro, fenfluramine (100 muM) affected none of these indices of central 5-HT synthesis except 3H-5-HT uptake, which it reduced, and synaptosomal 3H-5-HT release, which it facilitated. The effects of fenfluramine on 5-HT biosynthesis persisted longer than those of D-amphetamine, which lasted less than 24 hours. However, the fenfluramine effects were much shorter than those reported for p-chloroamphetamine, which persist for up to 3 months. These three amphetamines apparently affect the lateral midbrain raphe nuclei selectively.


Carbon-11 labeled aliphatic amines in lung uptake and metabolism studies: potential for dynamic measurements in vivo.

In order to assess the potential utility of amines labeled with short-lived nuclides as agents for lung imaging and function studies in humans, a series of aliphatic amines (C4-C10 and C13) labeled with carbon-11 (T 1/2 = 20.4 minutes), which decays by the emission of body-penetrating radiation, has been used as a model for studying some basic parameters affecting amine uptake and metabolism by the lung and other tissues in mice. The lung uptake (percentage of dose per organ) of aliphatic amines at 1 minute increased from 2.18 +/- 0.13% for butylamine to 13.33 +/- 0.84% for tridecylamine. Partition coefficients (between n-octanol and pH = 7 buffer) were measured for the C4 through C10 amines and for octanoic acid and octanenitrile. Within the amine series, the partition coefficient correlated with lung uptake. A comparison of a series of compounds all having a carbon chain length of eight but with different functional groups (--NH2, --C=N, --CO2H, --OH) showed that the amino group as well as the relatively lipophilic alkyl group were required for lung specificity. The 11C-aliphatic amines were rapidly metabolized via monoamine oxidase (ultimately to 11CO2). Non-amine metabolites in blood and lungs at 5 minutes postinjection were 95 and 50%, respectively. Pretreatment of mice with iproniazid and with pargyline decreased 11CO2 excretion, and iproniazid significantly increased the radioactivity retained by the brain, lungs and liver at 15 minutes. The rate of 11CO2 excretion depended on carbon chain length (C4 less than C5 less than C6 greater than C7 greater than C8 greater than C9 greater than C10 greater than C13).


Alteration by phosphatidyl serine of tension responses and 45Ca distribution in aortic smooth muscle.

The effects of phosphatidyl serine (PS) on 45Ca distribution, 45Ca movements and contractions were examined in rabbit aortic smooth muscle. Contractile responses to submaximal concentrations of norepinephrine and histamine were potentiated by prior exposure to PS, but equivalent responses to potassium were unaffected. Addition of PS to the incubation solution decreased 45Ca uptake; exposure of aortic strips to PS during washout of either 45Ca or promethium (147Pm) resulted in maintained increases in efflux. These PS-induced alterations in net loss of 45Ca or 147Pm can be attributed to a decreased membrane reuptake and/or rebinding. However, the presence of PS during the washout significantly reduced the increases in 45Ca efflux rate elicited with either 0.05 mM concentrations of Ca++ or ethylenediamine tetraacetic acid. Thus, in rabbit aortic smooth muscle, exogenous PS can alter the availability and/or exchangeability of a membrane-bound Ca++ fraction. By specifically increasing the affinity for Ca++ at relevant membrane sites or stores. PS may enhance the ability of vascular smooth muscle to respond to stimulatory agents that mobilize Ca++ from these sites and, in this manner, potentiate contractile responses.


A comparative study between the cardiovascular effects of cetiedil, a new vasodilator, and papaverine and aminophylline.

The cardiovascular effects of progressively increasing infusions of papaverine hydrochloride, aminophylline and cetiedil, a new vasodilator, were studied and compared in the anesthetized intact dog preparations. Papaverine and aminophylline had qualitatively the same effects on the various parameters, but in general the maximal effects of papaverine were of a greater order of magnitude. Cetiedil exhibited a different pattern of cardiovascular activity characterized by initial decrease in mean pulmonary arterial flow of 16% accompanied by an increase in systemic vascular resistance of 28% and in pulmonary vascular resistance of 19%, a stage of restoration of mean pulmonary arterial flow to control level accompanied by decrease in dp/dt of 25% and increase in pulmonary vascular resistance of 27% and a final stage of decrease in mean pulmonary arterial flow, representing toxic effects and accompanied by decrease in mean aortic pressure of 26%, dp/dt of 54% and heart rate of 27%, and an increase in pulmonary vascular resistance of 84%. These results indicate that cetiedil is devoid of cardiac stimulant activity. In another group of experiments devoted to measurement of vascular resistance of the hind limb, the results indicate that cetiedil, like papaverine and aminophylline, increased femoral blood flow through a decrease in resistance of the hind limb vasculature. This increase in flow could have been brought about only by redistribution of the cardiac output through differential effects on different vascular beds, since unlike papaverine and aminophylline, cetiedil does not increase cardiac output. The lesser maximal increase in femoral blood flow following cetiedil as compared to that following papaverine is probably referable to the relatively limited capacity of redistribution of the cardiac output to augment femoral blood flow. Superimposition of cetiedil and aminophylline on maximal effects of papaverine led to an additional decrease in mean femoral perfusion pressure, probably implying differences in basic mechanisms by which the three agents bring about their smooth muscle relaxant action.


Microcirculatory approach to the treatment of circulatory shock with a new analog of vasopressin, (2-phenylalanine, 8-ornithine)vasopressin.

Pressor amine therapy in circulatory shock has been generally unfavorable, presumably because these drugs produce unselective, intense vasoconstriction and curtail rather than improve true capillary inflow, distribution and outflow in the microcirculation. The present study compares the influence of a new analog of vasopressin, [2-phenylalanine, 8-ornithine]vasopressin (POV), over wide dose ranges and Ringer's solution on: 1) survival after circulatory shock, induced by different means (e.g., hemorrhage, bowel ischemia); 2) blood pressure and hematocrit in shocked animals; and 3) various microcirculatory parameters after induction of hemorrhage and bowel ischemia shock (e.g., lumen diameters of various types of microvessels, reactivity of microvessels, microvascular flow patterns, leukocytic sticking, petechial hemorrhage formations, vasomotion, etc.). Local administration of POV, in contrast to constrictor catecholamines, induces a venular-to-arteriolar profile of constrictor activity in the normal rat mesenteric microcirculation. Systemic administration of POV to rats subjected to either lethal hemorrhage or bowel ischemia shock: 1) increases survival rates 2- to 8-fold over control rats receiving Ringer's solution; 2) produces a plateau-like effect on arterial blood pressure and returns arterial hematocrits toward normal after hemorrhage; and 3) regenerates and sustains vasomotion and venular tone, decreases microvascular hyper-reactivity characteristic of shock syndromes, restores constricted arteriolar lumen sizes toward normal, predisposes to a splanchnic microbed virtually free of stasis and petechiae, and restores capillary perfusion and outflow to near-normal. These findings indicate that it is possible to synthesize vasoactive molecules which exert selective microvascular effects and are highly beneficial in therapy of low-flow states.


Respiratory and cardiovascular effects of prostaglandins in the conscious guinea pig.

A technique to assess respiratory and cardiovascular effects of prostaglandins (PGs) in conscious guinea pigs was developed. Animals were placed in a plethysmograph and tidal volume, airflow, and heart rate were recorded. In addition, blood pressure and/or pleural pressure were obtained. Some experiments involved the use of a pulmonary calculator that processed the appropriate pulmonary signal and provided on-line readout of dynamic compliance and airway resistance. Aerosolized antagonists were evaluated for their ability to block responses to aerosolized histamine. We found the relative antagonistic potencies of PGE1, PGE2, isoproterenol, and salbutamol to be 5.5, 2.3, 1 and 0.2, respectively. Aerosolized PGE1 and PGE2 but not PGF2alpha given prior to histamine caused decreases in tidal volume, airflow and heart rate. These effects were not seen in animals that were prepared for measurements involving invasive surgical techniques. The aerosolized PGE2 induced tidal volume changes were not prevented by pretreatment with salbutamol, chlorpheniramine, atropine or hexamethonium, though the latter two drugs inhibited the fall in heart rate. We suggest that the bradycardia following aerosolized PGE2 administration may originate from airway irritant receptors. The results validate use of our methods for the assessment of responses to bronchoactive agents under physiological conditions.


Effect of paraquat (methyl viologen) on liver function in mice.

Paraquat poisoning may result in pulmonary damage and hepatotoxicity. To examine the effect of paraquat on liver function, paraquat-treated mice were injected with sulfobromophthalein (BSP, 100 mg/kg) or indocyanine green (20 mg/kg) via the tail vein and plasma concentrations of these compounds were determined at various times. Hepatic concentrations of reduced glutathione were also determined following paraquat. Retention of BSP and indocyanine green in the plasma was observed 24 hours after paraquat. Body temperature of the poisoned mice was significantly depressed 24 hours after treatment and the paraquat-induced indocyanine green retention could be reversed by warming the paraquat-treated mice to normal body temperature. In contrast, paraquat-induced BSP retention was independent of body temperature. Inasmuch as hepatic glutathione concentrations were reduced 24 hours after paraquat treatment, the retention of BSP in the plasma may have been secondary to the reduction of hepatic glutathione concentrations.


Hepatic uptake and biliary excretion of d-tubocurarine and trimethyltubocurarine in the rat in vivo and in isolated perfused rat livers.

The clearance from perfusion medium and the biliary excretion of d-tubocurarine (d-TC) and trimethyltubocurarine (tMeTC) was studied in isolated perfused rat livers. Despite the related structure, d-TC exhibited considerably higher lipophilicity and plasma protein binding than its trimethyl derivative. Significant differences in hepatic disposition of the two agents were found. The clearance constant of elimination from the perfusate for d-TC was 2.00 and 0.41 ml/min for tMeTC. Fifty-one percent of the administered d-TC was excreted in the bile during 2 hours of perfusion. For tMeTC this amounted to only 16%. Bile/plasma concentration ratios of d-TC were 10 times those of tMeTC. There was no evidence for biotransformation of the substances. The unequal biliary output cannot be explained by differences in subcellular distribution. After injection into rats in vivo, the major part of drug in the liver is confined to the particulate fractions. Subfractionation studies indicate binding to lysosomes. The hepatocyte cytosol concentrations of d-TC and tMeTC are in the same order and are lower than the concomitant plasma concentrations. Both bile/liver and liver/plasms concentration ratios were higher for d-TC. The results support the idea that the balance of hydrophilic and hydrophobic properties is an important factor determining hepatic transport of organic compounds.


Toxicity of antitumor agents on hemopoietic colony forming cells.

The effects of selected antitumor agents--methotrexate, 6-mercaptopurine, cyclophosphamide, hydroxyurea and cytosine arabinoside on hemopoietic progenitor cells were determined by femoral and splenic colony forming cell (CFC) content after single and multiple injections of the agents. Mice were injected in groups of three with the agents on different days and killed on the same day. Major findings were: 1) All the antitumor agents (by single or multiple injections), with the exception of 6-mercaptopurine, caused an early reduction in the number of CFC per femur and an increase in CFC levels per spleen on day 7.2)CFC levels per 10(5) cells were significantly lower at 1 hour after single injections of hydroxyurea or methotrexate than at 24 hours after a single injection of either drug. 3) Multiple vs. single doses of hydroxyurea and cytosine arabinoside showed that multiple doses were more effective in reducing femoral CFC levels on day 1 and elevating splenic CFC content on day 7 than were single doses. 4) Multiple doses of 6-mercaptopurine were more effective than single doses in lowering femoral CFC levels on day 1, but all doses of 6-mercaptopurine failed to evoke a change in splenic CFC levels. 5) Multiple doses of methotrexate were not more effective than single doses in decreasing femoral CFC content and raising splenic CFC levels.


Effects of d-amphetamine, pentobarbital, chlorpromazine and promazine on electric shock postponement responding by the pigeon.

The effects of d-amphetamine, pentobarbital, chlorpromazine and promazine on responding under schedules of electric shock postponement were studied in pigeons. Responding was maintained by three different response-shock intervals (10, 20 and 60 seconds). Low doses (0.3-3 mg/kg) of d-amphetamine increased response rates without decreasing shock rates under all three response-shock intervals. The highest dose (10 mg/kg) of d-amphetamine increased the shock rates under all response-shock intervals and decreased the high response rate under the 10-second response-shock interval but did not decrease the lower rates of responding under the 20- and 60-second response-shock intervals. Pentobarbital decreased the high rate of responding maintained under the 10-second response-shock interval at lower dose (10 mg/kg) than the lower rates of under the 20- and 60-second response-shock intervals. The high dose (17.5 mg/kg) of pentobarbital decreased responding and the low doses (1-3 mg/kg) had no effect under all three response-shock intervals. Chlorpromazine (3-100 mg/kg) did not affect the average rate of responding under all response-shock intervals and only slightly increased shock rates under the 20- and 60-second response-shock intervals. Promazine (3-30 mg/kg) increased the rates of responding and decreased shock rates under all three response-shock intervals. Analysis of the temporal patterns of responding within the response-shock interval showed that d-amphetamine tended to induce the animals to respond earlier than they normally would in the response-shock interval while otherwise maintaining the temporal pattern of responding, pentobarbital decreased the probability of responses late in the response-shock interval, and chlorpromazine and promazine increased the probability of responses in the middle of the response-shock interval, producing a lessening of the temporal patterning of responding within the response-shock interval.


Operant acquisition of marihuana in man.

Operant work for marihuana cigarettes or money and the effects of marihuana smoking on behavior were examined in 12 casual and 15 heavy marihuana users. Male volunteers were studied in groups of four on a clinical research ward and each subject served as his own control. A 5-day base-line period was followed by a 21-day marihuana available period and a 5-day postmarihuana control period. Subjects could earn one 1-g marihuana cigarette or 50 cents by 30 minutes of sustained performance on a simple operant task. All casual and most heavy user subjects gradually increased marihuana smoking through time. The heavy users smoked more (4.3-6 cigarettes/day) than the casual users (2-3/day). Both groups worked between 2 and 5 times as many hours per day as was necessary to earn the number of cigarettes smoked. Consequently, subjects earned and saved far more money than was spent for marihuana. The heaviest smokers worked between 6.7 and 14.4 hours/day, every day. Periods of maximal work coincided with periods of maximal smoking, i.e., between 4 P.M. and 12 midnight each day. Delayed effects of marihuana dose on points earned the following day showed a dose-related decrement in operant work output. In the heavy user group, operant performance decreased sharply 24 hours after 3 ciagrettes/day were smoked, then remained relatively stable after 3 to 8 cigarettes daily and decreased further on the few occasions when more than 8 cigarettes were smoked. In the casual user group, the largest 24-hour delayed changes in performance occurred after the smoking of between 1 and 2 and 3 and 4 marihuana cigarettes. No subject stopped operant work even when he smoked 10 or more marihuana cigarettes per day. These data do not support the hypothesis that marihuana induces an "amotivational" syndrome.


Influence of the frequency of nerve stimulation on the metabolism of 3H-norepinephrine released from the perfused cat spleen: differences observed during and after the period of stimulation.

The metabolism of 3H-norepinephrine (3H-NE) released by different frequencies of nerve stimulation was studied in the perfused cat spleen after labeling the endogenous stores with (-)-3H-NE. For a wide range of frequencies of stimulation, unmetabolized 3H-NE represented between 50 and 60% of the total increase in outflow of radioactivity elicited by nerve stimulation. The deaminated glycol, 3,4-dihydroxyphenylglycol (3H-DOPEG), was the main metabolite of 3H-NE released by nerve stimulation. When the increase in outflow of radioactivity was analyzed for the samples collected during nerve stimulation, there was a progressive decrease in the fraction of 3H-NE released which was collected as 3H-metabolites as the frequency of stimulation was increased from 0.5 to 5 Hz. For the samples collected in the poststimulation period, there was no frequency dependence in the metabolism of the released transmitter: approximately 75% of the total overflow of radioactivity was accounted for by the 3H-NE metabolites, particularly 3H-DOPEG. The time course of the metabolism of 3H-NE released by nerve stimulation revealed that 3H-DOPEG formation was rather small during stimulation and that it increased sharply in the poststimulation samples. The selective increase in 3H-DOPEG formation in the poststimulation period is compatible with the view that neuronal uptake of the released transmitter might be increased immediately after nerve stimulation. Inhibition of neuronal uptake by cocaine or by phenoxybenzamine prevented 3H-DOPEG formation from 3H-NE released by nerve stimulation. Yet, in the presence of cocaine, the fractional release of total radioactivity per shock was not increased at either 1, 5 or 30 Hz. These results support the view that  a large fraction of the 3H-NE released by stimulation which is recaptured by nerve endings is metabolized to 3H-DOPEG rather than stored for subsequent reuse. The extensive conversion to 3H-DOPEG of 3H-NE released by nerve stimulation suggests that there may be a difference between the process of neuronal uptake under resting conditions and that which operates under conditions of nerve stimulation. This difference may be related to the concentration of the transmitter achieved in the synaptic gap in each experimental condition. Under resting conditions and during perfusion with low concentrations of NE, neuronal uptake in the perfused cat spleen is coupled with vesicular storage. On the other hand, when the extracellular concentration of NE is increased as a result of nerve stimulation, neuronal uptake of NE appears to be coupled with presynaptic metabolism through monoamine oxidase and aldehyde reductase.


Dopamine evoked inhibition of single cells of the feline putamen and basolateral amygdala.

1. In cats under pentobarbitone or halothane anaesthesia, neurones of the putamen and basolateral amygdala were inhibited with a similar time course by iontophoretic applications of dopamine and gamma-aminobutyric acid (GABA), ejected with relatively short (20 sec) low intensity (less than 40 nA) pulses of positive current from five and seven barrelled extracellular micropipettes.  The use of a stereotaxically positioned guide tube, sealed to the skull with dental cement, made it possible to obtain stable recording conditions and to correlate the stereotaxic position of the cells with the position of the micro-electrode tracks determined histologically by the post-mortem reconstruction of serial sections. 2. Since in cats anaesthetized with pentobarbitone none of the cells were found to be spontaneously active, the relative potency of dopamine and GABA were compared on glutamate excited cells. Approximately 2-5 times more current was required to release sufficient dopamine to cause just submaximal inhibition, equal in magnitude and duration to that evoked by GABA. 3. In nitrous oxide/halothane anaesthetized cats, approximately one quarter of the cells were spontaneously active. Relative potency studies showed that for dopamine, currents 2-0 and 1-6 times larger than those used for GABA were required to inhibit glutamate excited and spontaneously active cells respectively. 4. When the depth distribution of the cells was compared with the sensitivity of the cells to dopamine and GABA, the most sensitive cells were found to lie within the putamen and the basolateral amygdala. 5. On more than one third of the cells tested, iontophoretic application of the neuroleptic, alpha-flupenthixol of more than 3 or 4 min in duration, greatly reduced or abolished the inhibition of the cells by dopamine without impairing their sensitivity to GABA. 6. In four cats, large I.V. injections of alpha-flupenthixol (10 mg/kg) and the more potent neuroleptic pimozide (1 mg/kg) had no significant effect on the dopamine or GABA sensitivity of seventy cells in the putamen and basolateral amygdala. 7. Our results are in keeping with the view that dopamine has a predominantly inhibitory action in the mammalian forebrain. However the failure of I.V. neuroleptics to modify the sensitivity of the cells to dopamine suggests that the dramatic effects of neuroleptics on animal behaviour may not be explicable simply in terms of a generalized blockade of dopamine receptors at post-synaptic sites.


Reflex responses of gamma motoneurones to vibration of the muscle they innervate.

1. High frequency vibration was applied to the tendon of the non-contracting triceps surae muscle while recording the background discharges of single gamma fibres only small nerve bundles were cut, leaving most of the nerve supply to the triceps intact. 2. 22% out of a total of sixty-three gamma efferents were tonically inhibited by vibration. The inhibition appeared between 25 and 50mum peak-to-peak amplitude of vibration and increased to a plateau for amplitudes of about 100mum. The dependence of the tonic vibration reflex of alpha-efferents on the amplitude of vibration was found to be similar. Increasing the frequency of vibration from 150 to 300 Hz increased the degree of inhibition. 3. 33% of the fusimotor neurones investigated responded to muscle vibration with an increase in discharge rate. The threshold amplitudes of this reflex ranged from 20 to 50mum. Some features of the reflex, in particular the parallel post-vibratory facilitation found in alpha and gamma efferents, pointed to a polysynaptic pathway organized in an alpha-gamma linkage. 4. All gamma efferents inhibited by vibration showed inhibitory responses to antidromic stimulation of the parent ventral root, and most of them were inhibited by ramp stretch of the triceps. The gamma motoneurones facilitated by vibration, however, were excited by muscle stretch and were less susceptible to antidromic inhibition, some lacking it completely. 5. Cutting the nerves to triceps abolished the inhibitory as well as the excitatory responses of gamma efferents to muscle vibration. Both fusimotor reflexes were preserved after spinal section and subsequent administration of L-DOPA. 6. It is concluded that both of the fusimotor reflex effects of vibration are caused by excitation of primary spindle endings within the triceps. The inhibition of fusimotor neurones is thought to be mediated by Renshaw cells activated during vibration. The significance of positive feed-back on to gamma motoneurones as a result of autogenetic facilitation by Ia afferents is discussed in connexion with stability in the stretch reflex loop.


The study of (Methyl-3H)decamethonium dichloride incorporation into normal and dystrophic mouse muscle.

1. (Methyl-3H)decamethonium dichloride was injected intravenously into the tail vein of dystrophic and normal mice of the Bar Harbour strain 129 ReJ/dy in paralysing doses. 2. Scintillation counts were made of 1 mm sections of diaphragm and tibialis anterior which showed a normal distribution of tritiated decamethonium in the dystrophic animals. 3. Intraperitoneal injections of L-(gamma-3H)leucine were made into dystrophic and normal mice. Examination of diaphragm and tibialis anterior by scintillation counting showed the abnormal uptake typical of dystrophic involvement of murine muscle. 4. The normal distribution of (methyl-3H)decamethonium dichloride uptake by the dystrophic muscle does not support the concept of active denervation in this disease.