High titer glucagon antisera.

Antibody titers in rabbits immunized with glucagon conjugated to albumin using difluorodinitrobenzene rose rapidly. Under conditions of immunoassay, less than 2 nl of serum from two of four animals and approximately 4 nl from the other two was required to bind 50% of the 10 pg of [125I]iodoglucagon 100 days after immunization. The dissociation constants of the two higher titer antisera for glucagon were approximately 1 x 10(-10)M, and their binding capacities for the hormone, about 50 mug/ml. Competitive binding assays showed that neither of these antisera cross-reacts with the glucagon-like, immunoreactive peptides extracted from intestine to greater than 2.5%. In contrast, hens produced antisera which were reactive with the intestinal material and which bound only 0.3 mug of glucagon per ml. There were no consistent differences, however, in the abilities of specific and non-specific antisera to react with selected fragments of pancreatic glucagon.


Diminished ketosis and triglyceridemia during fasting in odd-carbon enriched pregnant rats.

The lipolysis, ketosis and hypertriglyceridemia of fasted rats in late pregnancy may be related to decreased insulin secretion geared to decreased glucose availability. In odd-carbon fatty acid enriched (OCE) rats, the odd-carbon fatty acids (OCFA) mobilized during fasting provide terminal three-carbon residues which are glucogenic, thereby permitting blood glucose and insulin to be maintained close to fed levels. The present study has used OCE rats to evaluate the role of insulin in the altered fat metabolism of the fasted rats in late pregnancy. The adipose tissue of 24 female Sprague-Dawley rats was enriched to more than 25% undecanoate (c11:0) and higher OCFA by feeding them a complete diet high in triundecanoin content for six weeks. Twenty-four female controls were fed a similar diet except that the fat was exclusively corn oil. Both OCE and control rats were than mated and on day 18 of pregnancy were divided into four groups: one group was killed fed, one after a 24 h fast, and one after a 48 h fast; the fourth group was fed to day 20 of pregnancy and then killed. In the fed state, the concentrations of glucose, ketones, and cholesterol in serum, as well as that of glycogen in liver, were the same in control and OCE rats. Insulin and triglycerides were similarly elevated in the two groups. After two days of fasting, serum glucose, insulin, and liver glycogen concentrations were significantly higher in OCE than in control rats, while ketones and triglycerides were significantly lower. No significant changes occurred in serum cholesterol. The results are consistent with a predominantly insulin effect in the pregnant OCE rats in diminsihing the marked fasting lipolysis, hyperketonemia and hypertriglyceridemia observed in controls, but do not rule out inhibition of FFA release by in situ re-esterification to glycerol derived from glucose or propionic acid.


Glucocorticoid receptors in adipose tissue.

Although adipose tissue appears to be a target organ for glucocorticoid hormones, previous studies have failed to detect glucocorticoid receptors in this tissue. In the present study, the addition of thioglycerol and trasylol to the homogenization medium provided an enuironment in which receptors were successfully demonstrated. [3H]Dexamethasone binding studies were carried out at 0 C in cytosol from various adipose tissues of adrenalectomized rats and bound hormone was separated from free by Sephadex chromtography. Despite the presence of protein protective agents, receptor binding decayed significantly over 24 h but appeared stable from 1 to 5 h. Epididymal fat pad cytosol had an apparent Kdiss at 0 C for dexamethasone of approximately 6 nM and a binding capacity of approximately 200 fmol per mg protein. To prove that the receptors were located in fat cells and not in surrounding connective tissue, isolated adipocytes were prepared by collagenase digestion and receptors were demonstrable in the cytosol from these cells as well. The affinity of series of steroids for the receptor was in the sequence: dexamethasone greater than corticosterone greater than progesterone greater than aldosterone greater than cortexolone greater than testosterone greater than estradiol. Receptors of roughly the same affinity but somewhat fewer binding sites on the basis of cytosol protein were also found on other fat depots including peri-renal, peri-scrotal and popliteal. Of interest is the fact that interscapular brown fat and human subcutaneous fat also possessed similar these receptors, the higher competitive capacity of dexamethasone indicated that the binding was to glucorticoid rather than mineralocorticoid receptors. The data suggest that fat cells contain glucocorticoid receptors which are similar to those seen in other glucocorticoid targets. Presumably these receptors mediate the effects of glucorticoids on adipose tissue.


Different nuclear binding sites for antiestrogen and estrogen receptor complexes.

Experiments were performed to determine the in vivo effect of various estrogens and anti-estrogens on the nuclear accumulation and retention of estrogen receptors, the cytoplasmic levels of estrogen receptors, and the formation of salt-resistant and salt-extractable forms of the nuclear estrogen receptor in immature rat uteri. A 5 mug injection of estradiol-17beta (E2) or diethylstilbestrol (DES) resulted in a maximal nuclear translocation of the receptor complexes by 1 h with a subsequent rapid decrease of both the estradiol receptor complex (ERC) and diethylstilbestrol receptor complex (DRC) to levels found in uteri of saline-injected rats by 12 h. However, the antiestrogens U-11,100A, zuclomiphene and enclomphene (100 mug/injection) resulted in a slower nuclear accumulation of receptor complex which continued to increase through 24 h. The cytosol receptor levels with E2 and DES were depleted to 10--20% of control levels within 1 h, but then were replenished so that they were above control levels by 24 h. The clomiphene-type compounds also showed an initial depletion of cytosol estrogen receptor, but the antiestrogens were almost ineffective in receptor replenishment. The estrogen receptor translocated to the nuclear fraction by estrogens demonstrated both salt-extractable (0.3M KCl) and salt-resistant forms at 1--6 h, whereas the clomiphene-type compounds resulted in the formation of only a salt-extractable form of the estrogen receptor at all times. By 12--24 h after injection, the salt-resistant forms of the ERC and DRC were no longer present. The effect of varying the dosage of injected E2 (0.05 mug-5 mug) resulted in the formation of an identical amount of salt-resistant ERC at 1--2 h, whereas the total amount of nuclear ERC (salt-resistant and salt-extractable) varied with the injected dose of E2. However, at 6 h, the amount of salt resistant ERC varied with the injected dose of E2 (0.005-5 mug). These results suggest that the nuclear salt-resistant form (formed by estrogens only) of the estrogen receptor is required for true uterine growth, whereas the nuclear salt-extractable form may be only sufficient for short term estrogenic responses.


Tissue-specific stimulation of ornithine decarboxylase activity by pituitary factors immunologically related to growth hormone.

Ornithine decarboxylase (L-ornithine carboxylase, EC 4.1.1.17) is an important enzyme in polyamine synthesis. Its activity is influenced by several peptides hormones, including growth hormones, which have physiological significance in various growth situations. A crude ovine pituitary growth hormone preparation (NIH-GH-S10) was subjected to gel exclusion chromatography (Sephadex G-100) and two major fractions were obtained. One of these corresponded to dimeric growth hormone (GH). The other fraction was excluded by the gel matrix, suggesting a material of higher molecular weight than GH. This was confirmed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Analysis of a high molecular weight fraction by radioimmunoassay (antisera prepared against GH) and by bioassay (weight gain in hypophysectomized rats) gave apparent GH contents of 19% and 6%, respectively. On a weight basis, the high molecular weight fraction was more effective than GH in stimulating the activity of hepatic and adrenal ornithine decarboxylase, but GH was more effective in stimulating renal ornithine decarboxylase activity. Subfractionation of the high molecular weight fraction using a high porosity gel (Sephadex G-200) gave four fractions, which were shown by amino acid analysis and by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate to be distinct from GH and heterogenous. These subfractions had different potencies for stimulating renal and hepatic ornithine decarboxylase activity. The ability of crude growth hormone preparations to stimulate ornithine decarboxylase activity in some tissues may be a function of pituitary factors, in addition to GH, which have minimal growth promoting activity.


Lack of effect of calcitonin on the regulation of vitamin D metabolism in the rat.

The infusion of calcitonin into intact rats increases the accumulation of 1,25-dihydroxy-[26-27-3H]vitamin D3 from 25-hydroxy-[26,27,-3H]vitamin D3 in blood, but has no effect on thyroparathyroidectomized rats using a variety of protocols. Furthermore, the vitamin D status of the animals did not alter the results. Inasmuch as no effect of calcitonin could be found on the accumulation of other vitamin D metabolites as well as 1,25-dihydroxyvitamin D3, it is concluded that calcitonin apparently plays no direct role in the regulation of vitamin D metabolism and that the previous report of an effect of calcitonin on vitamin D metabolism in vivo is probably the result of a secondary response of the parathyroid gland.


Morphological changes in prolactin cells of male rats after testosterone administration.

Intact and castrated 25- and 60-day-old male rats were given 200 mug of testosterone propionate (TP) daily for 15 consecutive days. The morphology of the prolactin (PRL) cells was examined by electron microscopy and analyzed by the point counting method of Weibel and Bolender (23). The PRL cells in the controls had long cytoplasmic processes that coursed between adjacent parenchymal cells. The Golgi complex was relatively small in these cells and the area occupied by the secretory granules was, in general, less than in the TP-treated animals. After TP administration, the cells became more ovoid and the Golgi complex enlarged, displaying dilated cisternae and many immature secretory granules. In addition, the diameter of the secretory granules was greater in the animals given the steroid. When the morphology of the PRL cells in the sexually immature control rats was compared to that observed in the older, sexually mature rats, relatively few differences were observed indicating that the response to TP was essentially the same in animals of both age groups. The concentration of PRL was measured in the serum and pituitary gland by radioimmunoassay. There was a significant elevation in PRL in both the serum and pituitary glands of all animals given TP. In contrast, castration led to a fall in PRL levels. From these observations and from the morphological data it can be concluded that TP is capable of stimulating the rate of PRL synthesis and release, and that testosterone may have a regulatory role in PRL biosynthesis and turnover in the male rat.


Post-coital contraceptive activity and estrogen receptor binding affinity of phenolic steroids.

Estradiol, estradiol-16alpha, estriol and a series of positional isomers of estriol were tested for their post-coital contraceptive activity, and their ability to compete with estradiol for the cytosolic estrogen receptor protein of rat uteri. Estrogenicity was determined for each compound in immature rats with single injections and in mature castrated rats by injecting the lowest fully contraceptive dose for four consecutive days. All compounds were active anti-implantational agents, varying in required dosage from 4 mug to 2000 mug (total dosage over 4 days). The rank order or contraceptive activity was found to be: estradiol greater than estriol = epiestriol greater than 11beta - (OH) - estradiol greater than estradiol - 16alpha greater than 7alpha-(OH)-estradiol greater than 6beta-(OH)-estradiol, while the order of estrogenicity at levels of contraceptive activity in the ovariectomized mature rat was: epiestriol = estriol less than 7 alpha - (OH) - estradiol less than estradiol - 16alpha less than 6beta - (OH) - estradiol = 11beta - (OH)- estradiol less than estradiol-17beta. Reasonably good correlation between competition for estrogen receptor and anti-implantational activity was observed. The most active binding competitors were estradiol-16alpha, epiestriol, and estriol which showed an affinity from 50-20% that of estradiol, while the other compounds had 3% or less binding competition for estradiol.


Biosynthesis and secretion of calcitonin by avian ultimobranchial glands.

The biosynthesis and release of calcitonin from chicken ultimobranchial glands were evaluated both in vivo and in vitro. Changes in the content of calcitonin in plasma and ultimobranchial glands of chicks during embryonic development were measured using a radioimmunoassay for salmon calcitonin that readily detects chicken calcitonin. Calcitonin content of the ultimobranchial glands underwent a striking rise during the late-embryonic and newborn periods, and a transient phase of brisk calcitonin secretion into blood was observed at the time of hatching. Ultimobranchial glands from late-embryo and newborn chicks, when incubated in vitro with radioactive leucine, incorporated labeled leucine into protein and released radioactive protein into the culture medium linearly over a period of 30 h. Analyses, by electrophoresis on polyacrylamide gels and by reactivity with anti-calcitonin sera, of radioactive protein released into the media revealed two radioimmunoassayable and immunoprecipitable peaks of chicken calcitonin. The two peaks could not be distinguished by their molecular weights upon electrophoresis on urea-SDS gels. These observations are most consistent with the existence of two isohormones of chicken calcitonin. No evidence for a biosynthetic precursor of calcitonin was obtained. Changes in calcium concentrations between 1.0 and 3.5 mM is incubation media in vitro did not affect release or storage of calcitonin, and changes in dietary calcium intake did not produce observable in vivo alterations in calcitonin content of ultimobranchial glands.


Brain cell nuclear retention of testosterone metabolites, 5alpha-dihydrotestosterone and estradiol-17beta, in adult rats.

Radioactivity was analyzed in tissue homogenates and purified cell nuclear fractions in the pituitary and 9 brain regions 2 h after an iv [7-3H]testosterone infusion into gonadectomized-adrenalectomized adult male and female rats. Unchanged testosterone (T) and its metabolites, 5alpha-dihydrotestosterone (DHT) and estradiol-17beta (E2), were the predominant steroids recovered from cell nuclear fractions in all brain regions examined. Highest levels of E2 as a T metabolite were found in nuclear fractions from the amygdala, followed by the hypothalamus, preoptic area and septum, while levels of DHT as a T metabolite were highest in nuclear fractions from the pituitary, followed by the hypothalamus and the septum. The regional pattern was similar in both sexes. Low levels of DHT and E2 recovered from serum indicated these metabolites were probably formed in situ. Regional distributions of cell nuclear retained DHT and E2 as T metabolites were compared with the respective regional distributions observed after either [1,2-3H]DHT or [6,7-3H]E2 infusion. Cell nuclear levels of E2 as a T metabolite did not correlate well with nuclear retained radioactivity after [3H]E2 injection, but cell nuclear levels of DHT as a T metabolite did correlate with nuclear radioactivity after [3H]-DHT infusion. No apparent sex differences were observed in nuclear-associated radioactivity after [3H]-E2 or [3H]DHT injections. The results emphasize the potential importance of local aromatization in the brains of rats of both sexes, suggest the existence of a DHT receptor site at the brain cell nuclear level, and confirm the existence of estradiol-17beta cell nuclear receptors in the adult male rat brain.


5alpha-Dihydrotestosterone (DHT) receptors in rat brain and pituitary cell nuclei.

Gonadectomized-adrenalectomized (GX-ADX) adult male rats were injected iv with 2-4 mug/kg [1,2-3H]DHT and sacrificed 2 h later. Whole tissue homogenates and purified cell nuclear fractions were prepared from various brain regions and the pituitary and analyzed for radioactivity. Cell nuclei from pituitary and most limbic-hypothalamic regions (but not cerebral cortex) concentrated radioactivity (per unit protein) over whole tissue levels. The highest levels of nuclear-associated radioactivity were present in pituitary, hypothalamic and septal tissues. Analysis of radioactivity by double isotope dilution, chromatography, and recrystallization revealed that unmetabolized DHT represented 96 and 95% of the nuclear-associated radioactivity in pituitary and pooled limbic-hypothalamic structures, respectively. Simultaneously administered 100-fold molar excesses of unlabeled 5betaDHT, progesterone or corticosterone did not reduce nuclear-retained [3H]DHT, while unlabeled 5alphaDHT competed strongly. The anti-androgen, cyproterone acetate, competed at doses capable of of blocking androgen-mediated neuroendocrine effects. Levels of nuclear-retained [3H]DHT were negligible in intact males, but rose markedly 24 h after castration-adrenalectomy, remaining stable for 2 weeks post-operatively. Density gradient centrifugation of pituitary or brain cell nuclear salt extracts (0.4M KCl) revealed the [3H]DHT bound to a macromolecule sedimenting at 3--4S. The characteristics of DHT brain and pituitary cell nuclear binding are compared with the respective characteristics of neural cytosol and ventral prostate nuclear androgen binding components. These preliminary data suggest the existence of the functional, steroid-specific, stereospecific cell nuclear androgen receptor in the adult rat brain and pituitary.


Studies on the concentrations of chloramphenicol in the serum and cerebrospinal fluid of neonates, infants, and small children. Reciprocal reactions between chloramphenicol, penicillin and phenobarbitone.

The interactions between chloramphenicol, penicillin and phenobarbitone were investigated in 383 children (premature and neonate children, infants and small children). As expected, the chloramphenicol concentrations in the serum of the newborns was considerably higher than that of infants and small children with the same dosage of chloramphenicol. In the age group of the premature and newborn children and infants there was significantly higher total chloramphenicol concentrations with the chloramphenicol-penicillin combination than with chloramphenicol monotherapy. Addition of phenobarbitone to the combination significantly reduced the chloramphenicol concentrations in the neonates. Lowering of the serum chloramphenicol concentrations by phenobarbitone could not be statistically confirmed in the infant age group. Combinations of chloramphenicol with ampicillin, gentamycin or cephalosporin derivatives showed no influence on serum chloramphenicol concentrations. Transference of chloramphenicol from the serum to the cerebrospinal fluid was about twice as high in the acute inflammatory stage as when the meninges were no longer acutely diseased (60 and 30% respectively of the serum concentrations). The passage of chloramphenicol to the cerebrospinal fluid showed no dependence on age.


Selective vitamin B12 malabsorption (Imerslund-Gräsbeck syndrome). Studies on gastroenterological and nephrological problems.

In a girl 10 years of age with selective vitamin B12 malabsorption associated with proteinuria and residual symptoms of funicular myelosis an extensive study of the intestinal and nephrologic functions was done. Repeated Schilling tests pointed to a malabsorption pattern of vitamin B12. Gastric acid and intrinsic factor secretion as well as gastric morphology were normal. There were no antibodies against intrinsic factor and parietal cells in serum. Ileal mucosa showed on light- and electron-microscopy no pathologic changes. Pancreatic exocrine function as well as pH and calcium concentrations in the lumen of the gut were within the normal range. A general malabsorption syndrome could be excluded. A high selective glomerular proteinuria was found through different methods. Inulin clearance was slightly reduced, PAH clearance, however, markedly so. There was no further evidence for renal tubular dysfunction. Renal biopsy showed a minimal proliferative intercapillary glomerulonephritis (minimal changes). In electron-microscopic studies a fusion of a part of the foot processes of the podocytes was found. No familialhistory of the syndrome could be demonstrated in our patient.


Comparative evaluation of intravenous phenytoin, procainamide and practolol in the acute treatment of ventricular arrhythmias.

Ten patients with a persistent ventricular arrhythmia, but no other sign of heart disease, were studied by means of an exercise test performed 4 times with a fixed work load, over 30--40 min. No drug was given in the first exercise test and in the others phenytoin, procainamide or practolol were chosen at random for i.v. administration. Blood samples for determination of plasma concentration were frequently collected. The ECG was recorded continuously during the exercise test and was analysed minute by minute. Despite plasma levels within the suggested therapeutic range, only procainamide showed a statistically significant antiarrhythmic effect in this group of patients.


Effect of chlorpromazine on blood glucose and plasma insulin in man.

In three groups of normal subjects and in one group of patients with latent diabetes mellitus a study has been made of the effects of chlorpromazine (CPZ) on blood glucose and plasma insulin. CPZ 75 mg/day for 7 days did not alter the plasma insulin response after oral glucose; nor did CPZ 50 mg/day for 7 days affect the glucose assimilation rate or insulin response to glucose injection. Infusion of CPZ 50 mg in 60 min slightly increased the basal blood glucose level but had no significant effect on basal plasma insulin. The insulin/glucose ratio after the end of the infusion was significantly higher than during the period of infusion of the drug. In latent diabetic patients CPZ infusion significantly diminished the insulin/glucose ratio during an intravenous glucose tolerance test. These results suggest that, whereas prolonged treatment with low doses of CPZ did not modify glucose tolerance and glucose-stimulated pancreatic response, higher acute doses of the drug may induce hyperglycaemia and can inhibit insulin secretion both in normal man and in patients with latent diabetes mellitus.


Influence of acute renal failure on the protein binding of drugs in animals and in man.

Serum protein binding of phenylbutazone has been measured in the rat, guinea pig, cat, rabbit and dog, and the influence on it of renal failure induced by uranyl nitrate injection has been studied. In all speciies a clearcut decrease in binding was observed after the occurrence of renal failure; the time course of the fall in binding correlated well with development of renal failure. In further experiments, serum protein binding of two acidic drugs (phenylbutazone, warfarin), two basic drugs (papaverine, quinidine) and one neutral drug (digitoxin) was studied in rabbits with experimental renal failure, and the results compared with those obtained in patients with acute renal failure. In the rabbits, a decrease in the binding of phenylbutazone, warfarin, papaverine and quinidine was found, whereas protein binding of digitoxin was unchanged. In man, there was a definite fall in protein binding of phenylbutazone and digitoxin, a small decrease for warfarin and papaverine, and a slight increase for quinidine.


Polymorphic acetylation of sulphadimidine in normal and uraemic man.

After oral administration of sulphadimidine (mean dose 3.33 g) to 21 volunteers it was possible to distinguish fast and slow acetylators by calculating the acetylated fraction (%acSDD) in a single serum sample obtained at any time between 1/2-24 h. There was a close correlation between %acSDD in serum and in urine collected from 0-8 h. Two groups of patients with chronic renal failure were studied. Four of the first 8 patients studied would have been designated as slow acetylators from their low %acSDD in 0-8 h urine, but as fast acetylators from their %acSDD in serum 6 h after drug administration. The next 18 patients were given a smaller dose of SDD (2 g) and they showed complete intra-individual correlation between %acSDD in 0-24 h urine and in a serum sample obtained at 24 h. The patients could be divided into 2 sub-groups on the basis of %acSDD in serum and urine, thus demonstrating the ability of this procedure to distinguish fast and slow acetylators, even in advanced chronic renal failure.


Distribution of pentobarbital and diphenylhydantoin between plasma and cells in blood: effect of salicylic acid, temperature and total drug concentration.

The binding of pentobarbital, diphenylhydantoin and salicylic acid to cells in blood was found to be independent of total drug concentration within therapeutic levels. Salicylic acid displaced pentobarbital and diphenylhydantoin from plasma protein binding sites, but high levels of salicylic acid had no effect on the distribution of the other two drugs to washed blood cells. Thus, in whole blood the presence of salicylic acid decreased the fraction of pentobarbital or diphenylhydantoin bound to plasma proteins and increased the fraction of the drug in plasma water and in blood cells. Diphenylhydantoin was shown not to be bound irreversibly to blood cells and equilibration in between the inside and outside of the cells was found to be rapid (within 5 min), even at high concentrations. Binding to washed blood cells was the same at 37 degress C and 25 degrees C, in contrast to plasma protein binding. It is pointed out that these effects may cause certain analytical errors, resulting in changes in plasma concentration if plasma is separated at a low temperature.


Dizepam metabolism in human foetal and adult liver.

Diazepam was metabolized by human foetal liver microsomes to N-desmethyldiazepam and N-methyloxazepam as early as the 13th week of gestation. The metabolic activity was lower than that of microsomes from adult human liver. Diazepam was shown mainly to be hydroxylated to N-methyloxazepam at substrate concentrations higher than 0.1 mM. Diazepam levels above 1.0 mM were inhibitory to the overall metabolic reaction. SKF 525-A inhibited diazepam metabolism by foetal liver microsomes at a concentration of 0.1 mM. The addition of diazepam to foetal and adult human liver microsomes resulted in a type II spectral change. Its inhibition by carbon monoxide indicated that biotransformation of diazepam was performed by the cytochrome P-450-linked mono-oxygenase system.


Pharmacokinetic aspects of protriptyline plasma levels.

Plasma levels of protriptyline have been determined in 30 patients undergoing antidepressant therapy. After 3 1/2 weeks treatment at dosage levels of 40 mg/day, protriptyline plasma levels ranged from 430 to 1430 nmol/l. During this period only two-thirds of the subjects had definitely achieved asymptotic concentrations. Single dose studies in 5 volunteers suggest that the volume of distribution of protriptyline shows little intersubject variation. The half life of the drug, however, may vary appreciably from subject to subject, ranging from 54 to 198 h. The effects of two sedatives on mean protriptyline plasma levels have been determined. Mean plasma levels for nitrazepam recipients are indistinguishable from those for patients receiving no night sedation. The mean plasma levels for a group of patients receiving sodium amylobarbitone were significantly reduced. The problems of choice and early adjustment of dosages in order to achieve satisfactory plasma levels is discussed. For practical purposes it is suggested that early values may be of predictive significance in allowing early dosage adjustments to be made.


Model independent derivation of general equations for the "first-pass" effect and extra-hepatic drug elimination.

A general expression for the ratio of areas below the blood concentration-time curves after intravenous and oral drug administration is derived. This derivation does not require the assumption of a specific compartmental model to describe drug distribution within the body. Similarly an expression for the amount of drug metabolised in the liver is derived. The latter expression is used to estimate the extent of extra-hepatic drug elimination from the body.


Simultaneous determination of therapeutic plasma concentrations of pethidine and norpethidine in man by electron capture gas chromatography.

An analytical procedure for the simultaneous determination of pethidine and its N-Demethylated metabolite, norpethidine, in plasma is described. Pethidine and norpethidine are separated by partition chromatography, converted to the trichloroethyl carbamate with trichloroethyl chloroformate and determined by electron capture gas chromatography. The smallest amounts of pethidine and norpethidine determined by the method were 10 and 2 ng, respectively, in 0.1 ml plasma. The relative standard deviation in the determination of 50 ng of pethidine and 40 ng of norpethidine in 0.1 ml plasma wwere 5.8% (n = 8) and 6.3% (n = 10), respectively. The method was used to determine plasma levels of pethidine and norpethidine in three patients who received subcutaneous doses of pethidine 50-75 mg for postoperative pain. The peak levels of pethidine were found to be in the range 200-400 ng/ml, with a plasma half-life of the order of 4 hours. The levels of norpethidine were low.


Inhibition of adrenaline-induced platelet aggregation by the orally administered alpha-adrenergic receptor blocker phentolamine (Regitine).

In eight healthy volunteers pretreatment with phentolamine 40 mg p o inhibited platelet aggregation (1st and 2nd phases) induced by low concentrations of adrenaline (2, 1 and 0.5 muM) in plasma from blood sampled 30 min after administration of the compound. The lower the concentration of adrenaline use, the greater was the degree of inhibition elicited. These results are indicative of competitive inhibition of the action of adrenaline on the platelet membrane by phentolamine. Four to six hours after administration of the compound, the aggregation characteristics had reverted to normal. It is concluded that the increased tendency toward platelet aggregation associated with elevated blood levels of catecholamines can be prevented by therapeutic doses of phentolamine.


Salivary phenytoin radioimmunoassay. A simple method of the assessment of non-protein bound drug concentrations.

A simple, specific and rapid radioimmunoassay (RIA) method for the assessment of non-protein bound ('free') phenytoin (DPH) concentrations in mixed saliva is described. Epileptic patients on maintenance phenytoin therapy have mixed saliva phenytoin concentrations similar to 'free' drug levels measured directly in serum or cerebrospinal fluid (CSF), Salivary phenytoin levels are approximately 10% of the total serum level in treated epileptic patients and in normal subjects after ingestion of a single oral dose. The half time of disappearance of phenytoin after 100 or 300 mg doses is 12.2 +/- 3.0 (SD) h in serum and 12.3 +/- 3.2 (SD) h in saliva. This method of assessing the biologically active fraction of the drug may be particularly valuable in situations where serum protein binding is abnormal or in drug interactions. It is also non-invasive and requires small sample volumes (20mul) and may therefore be valuable in paediatric practice and in pharmacokinetic studies in which multiple venepunctures would otherwise be required.


The effects of arachidonic acid in isolated atria of guinea pigs.

The effects of free and albumin-bound arachidonic acid, which is the precursor of the prostaglandins E2 and F2alpha, were studied on the spontaneous rate, contractile force and myocardial fatty acid metabolism in isolated, spontaneously beating atria of guinea pigs. Both free and albumin-bound arachidonic acid (10(-6)-10(-3) M) produced a dose-dependent positive chronotropic and a modest inotropic action. Tachyphylaxis to the positive chronotropic action of arachidonic acid developed in the course of repeated applications. Beta-Adrenoceptor blockade (pincolol) and pretreatment with reserpine or prostaglandin-synthetase inhibitors (indomethacin, fenoprofen, aspirin, 5,8,11,14-eicosatetraynoic acid) failed to affect the chronotropic activity of arachidonic acid significantly. The action of arachidonic acid was independent of the decarboxylation of the fatty acid. Linoleic and oleic acids did not show any positive chronotropic activity. The data are interpreted as suggesting that changes induced by arachidonic acid might be partly due to peroxides formed from arachidonic acid.


The effects of destruction of noradrenergic ascending ventral bundles and tetrabenazine on formation of stress-induced gastric ulcer.

The possibility that hypothalamic noradrenaline (NA) plays a role in the formation of gastric ulcers under stress via ventral bundles (VB) was examined in rats after bilateral destruction of VB. After a 3-h restraint stress ulcerative changes were observed in the stomach of sham-operated rats. NA contents in the hypothalamus and cerebral cortex decreased as compared to the respective contents before stress. The VB-lesioning inhibited the stress-induced decrease of NA in the hypothalamus. Ulcer indices in the animals 1 or 7 days after the VB-lesioning, however, did not differ from those of controls. Pretreatment of sham-operated controls with tetrabenazine enhanced the stress-induced decrease of NA in the brain, and exacerbated the gastric ulceration. VB-lesioning completely blocked these effects of tetrabenazine. It appears that the tetrabenazine-induced mobilization of hypothalamic NA via VB causes an aggravation of gastric ulceration.


The effect of testosterone and of castration on anococcygeus muscle contractility and on plasma corticosterone levels in the rat.

The effect of testosterone and of castration on the contractility of the rat anococcygeus muscle, on plasma corticosterone concentrations, and on adrenal gland weights, was investigated. Castration was without effect on smooth muscle reactivity. However, testosterone increased muscle contractility to both NA and ACh, when given to control or castrated rats. Castration reduced both plasma corticosterone and adrenal gland weight, and this effect could be reversed by testosterone. It is concluded that changes in circulating testosterone levels cannot explain the lack of effect of adrenalectomy on muscle contractility. The possible mechanism of action of testosterone is discussed.


Inhibition by PGE2 and by phenylephrine of catecholamine release from human adrenal in vitro.

The release of catecholamines from human adrenal was studied by in vitro incubation of slices. Catecholamine release was significantly inhibited by the addition of either phenylephrine (10(-5) M) or PGE2 (10(-7) M) to the incubation medium. The similarity of these modulating actions to those found in rat adrenal is discussed.


Lack of stimulation by high amphetamine doses following a low dose of spiperone.

The locomotor stimulant and stereotypic effects of amphetamine were investigated in rats pretreated with the specific dopaminergic blocker spiperone (0.25 mg/kg). Amphetamine doses from 8.0 to 64.0 mg/kg failed to stimulate behavior significantly and consistently after spiperone treatment. These results suggest the possibility of non-competitive antagonism by spiperone at dopaminergic synapses.


Action of methylxanthines and imidazole on the contractility of the terminal ileum of the guinea pig.

Methylxanthines (aminophylline and caffeine) and imidazole, substances with an opposite action on phosphodiesterase (PDE), were found to contract the terminal ileum and to potentiate nerve-mediated responses--contractions elicited by electrical stimulation (ES) at 3 Hz and 30 Hz. Imidazole-induced contractions which were partly reduced by atropine, potentiated both responses to ES to about the same extent, and enhanced contractility of the preparation to histamine and potassium. The action of imidazole on the terminal ileum could be related to its influence on PDE in the smooth muscle. The effects of aminophylline and caffeine were found to be more complex, possibly involving some mechanisms other than inhibition of PDE. They produced atropine-sensitive contractions of the terminal ileum, which were potentiated by physostigmine and strongly depressed by hemicholinium. In the presence of atropine, they potentiated ES-induced contractions, particularly those elicited by ES at 30 Hz, which are thought to be of adrenergic origin. Both actions appeared to be due to presynaptic effects -- activation of cholinergic and adrenergic neurons in the intestinal wall, possibly by enhanced influx of calcium, and facilitated release of acetylcholine and noradrenaline. Aminophylline, in concentrations which potentiated nerve-mediated contractions elicited by ES, did not affect direct smooth muscle-contracting action of drugs. Higher concentrations of aminophylline, above 0.1 mM, were found to inhibit histamine- and noradrenaline-induced contractions presumably due to inhibition of PDE in the smooth muscle and subsequent elevation of cAMP levels.


Submaxillary secretion in rats treated with guanethidine.

The composition of final submaxillary saliva and of whole gland homogenates were compared in rats treated with 14 daily doses of guanethidine (20 mg/kg body weight) and in untreated controls after stimulation with pilocarpine (10 mg/kg) or carbamylcholine (50-100 mg/kg). A 44% reduction in the volume of saliva and elevations in the salivary concentrations of K+, Ca2+ and protein were found in the treated animals after pilocarpine stimulation. Similarly, a 25% reduction in salivary volume and elevations in salivary Ca2+ and protein concentrations were observed following stimulation with carbamylcholine. A less significant elevation in salivary K+ was seen after this secretagogue. The Na+ and protein contents, but not the K+ and Ca2+ contents, were found to be elevated in the glands of the treated animals in the resting (unstimulated) state. After stimulation with the two secretagogues, however, similar changes in glandular Na+ and K+ contents were found in the glands of control and treated animals. The glandular water content was also similar in both types of glands in the resting and stimulated states. It is concluded that a reduced salivary secretion, rather than supersensitivity, is observed in the rat submaxillary gland following chronic guanethidine administration. The drug treatment does not impair the glandular electrolyte changes that occur upon stimulation, but most likely impairs the release of protein from the gland and also transductal K+ transport. Both these effects may result from the depletion of sympathetic neurotransmitter caused by the guanethidine administration.


Effect of papaverine on the frequency-force relationship in guinea-pig left atria.

Contractile responses of guinea-pig atria to papaverine were analyzed under different stimulation frequencies. Atria, driven at 2 Hz, showed positive inotropic responses to papaverine which were maximal within 10-15 min. These responses were maintained for 60 min in the presence of low concentrations of papaverine (up to 10(-5) M), but reversed into marked negative inotropic effects under the influence of higher concentrations. The well-known frequency-force relationship was reversed by papaverine. At low stimulation rates papaverine elicited positive inotropic responses, which gradually decreased with increasing frequencies until strong cardiodepression occurred. A frequency-force curve obtained in the presence of both the Ca2+-antagonistic drug D 600 and the inhibitor of the phosphodiesterase theophylline was similar to that obtained under the influence of papaverine. Theophylline alone evoked positive inotropic effects at all frequencies studied and left the character of the ascending staircase unchanged. In contrast, D 600 was ineffective at low, but cardiodepressive at high stimulation frequencies. In the presence of D 600 or papaverine high external Ca2+ could not restore a normal frequency-force relationship. The reversal of the frequency-force relationship as produced by D 600 and papaverine could not be obtained by lowering of the external Ca2+. The present results show that papaverine is able to evoke marked positive inotropic effects at low stimulation frequencies by inhibition of phosphodiesterase. At high frequencies, however, these effects are masked by negative inotropic responses due to the inhibitory action of papaverine on Ca2+-exchange of the cardiac muscle cell.


Effect of sympathomimetic amines on the synaptosomal transport of noradrenaline, dopamine and 5-hydroxytryptamine.

The interaction of sympathomimetic amines with the transport of 3H-noradrenaline (3H-NE), 3H-dopamine (3H-DA) and 3H-5-hydroxytryptamine (3H-5-HT) were investigated in rat hypothalamic (3H-NE) and striatal (3H-DA) and 3 H-5-HT) synaptosomes. Modifications in the phenylethylamine structure led to changes in activity towards biogenic amine uptake and release: (a) the introduction of a beta-OH group led to compounds less active in inhibiting uptake and stimulating release of 3H-NE, 3H-DA and 3H-5-HT, with the exception of 3H-NE release which was stimulated more by unlabeled 1-NE than by DA; (b) the introduction of phenolic-OH groups always led to compounds which were stronger uptake inhibitors and releasers of the three biogenic amines; (c) the alpha-methylation increased the potency towards uptake inhibition and release stimulation, with the exception of 3H-NE release: in fact, the releasing activity of phenylethylamine was suppressed by alpha-methylation; (d) the introduction of a -Cl group in the para position selectively potentiated the effects on 3H-5-HT uptake and release and generally depressed those on catecholamine transport.


Environmental stress as a factor in the response of rat brain catecholamine metabolism to delta8-tetrahydrocannabinol.

In rats housed normally (aggregated, food and water ad lib) for fourteen days delta8-tetrahydrocannabinol (THC) produced mild sedation and minimal hypothermia. An increase in noradrenaline synthesis was observed, but brain dopamine metabolism was unchanged. In rats removed from this 'normal' environment to conditions of isolation and food deprivation for 24 h THC produced immobility, marked hyper-reactivity, and hypothermia. Brain noradrenaline metabolism was unchanged by THC under these conditions, but significant changes in striatal dopamine metabolism were observed. These changes are consistent with increased dopamine reuptake in striatum produced by this combination of THC and novel environment. It is suggested that some of the behavioural effects of cannabis administered under stressful conditions may be related to alterations in striatal dopamine metabolism.


Characteristics of the relaxant response of adenosine and its analogs in intestinal smooth muscle.

Several characteristics of the relaxant response of the isolated longitudinal muscle of the rabbit small intestine in response to the administration of adenosine and related compounds are studied. Following administration of adenosine or ATP the preparation responded with a rapid initial suppression of spontaneous contractile activity followed by a secondary sustained phase of inhibition of lower magnitude. Cumulative application of relaxant doses of adenosine or ATP caused a lesser total response than that obtained by single application of the cumulative dose. Neither procaine, lidocaine or guanethidine antagonized the responses to adenosine or ATP and the responsiveness of muscles obtained from reserpinized animals appeared unchanged. A number of adenosine derivatives and analogs was tested for the ability to relax the muscle. Generally, compounds containing a primary or secondary 6-amino group acted as agonists with the exception of 8-bromoadenosine. Those nucleosides found to be inactive did not modify the responsiveness of the muscle to adenosine. Responses to adenosine and ATP were not appreciably modified by papaverine, imidazole, dipyridamole, 6-(p-nitrobenzylthio)-purine riboside. Antagonism was observed, however, with phentolamine and theophylline. Theophylline at 100 muM inhibited responses to adenosine over a wide dose range; this antagonism was surmountable by high doses of adenosine. 1-Methyl-3-isobutylxanthine did not antagonize adenosine responses. A number of 1,3-alkyl-6-thioxanthines did not modify the adenosine response at doses that did not show any direct action. The results supported the concept of an extracellular receptor site of adenosine and its analogs and the absence of an indirect mechanism of action via nerve stimulation.


Effects of glucagon on the renal hemodynamics of dogs.

An intrarenal infusion of glucagon resulted in an increase of glomerular filtration rate (GFR) with the same order of magnitude of renal blood flow (RBF) but did not affect the intrarenal distribution of blood flow. A superimposition of acetylcholine and glucagon decreased GFR even though RBF increased significantly. These findings indicate that the effect of glucagon on GFR depended on the selective dilation of afferent arterioles without any change in permeability of glomerular capillaries and redistribution of filtration.


Effect of clonidine and chlorpromazine on centrally evoked electrodermal responses and their interaction with yohimbine.

Both clonidine and chlorpromazine reduced the amplitude of electrodermal responses (EDR) evoked by stimulation of the hypothalamus at a constant submaximal frequency (10-16 Hz). The ED50 for clonidine was approximately 5 mug/kg and that for chlorpromazine was about 1 mg/kg. Yohimbine pretreatment (0.5 mg/kg, i.v.) antagonized the effects of clonidine but did not alter the effectiveness of clorpromazine in inhibiting these responses. Yohimbine alone was without effect on these sympathetic-cholinergic responses. These results suggest that clonidine and chlorpromazine deress central sympathetic reactivity by different mechanisms.


Catecholaminergic involvement in the effects of amphetamine isomers on seizure susceptibility.

The (+)-amphetamine (2.5 mg/kg) increase in pentylenetetrazol seizure was abolished by pretreatment with reserpine, alpha-methyltyrosine methyl ester (alpha-MT), FLA-63 or 6-hydroxydopa. All treatments except reserpine antagonized the increase in seizure threshold produced by (-)-amphetamine (4 mg/kg). Only reserpine +alpha-MT antagonized the decrease in seizure threshold produced by (+)-amphetamine (15 mg/kg). These results indicate that amphetamine alterations in PTZ seizure susceptibility are mediated indirectly via the release of newly synthetized and/or granular stores of catecholamines.


Effects of denervation and reserpine on nexuses in the rat vas deferens.

Permanganate-fixed vasa deferentia from rats were examined for the presence of nexal-like contacts by electron microscopy. There was a significantly greater incidence of nexuses (2X) in chronically denervated tissues (5-7 days) but not in tissues from reserpine-pretreated animals (1.0 mg/kg/day for 5-7 days). The results suggest that an increase in nexal regions may not be a general feature of postjunctional supersensitivity but rather may contribute to other denervation-induced changes in contractile response.


Hematologic effects of a single dose of methylnitrosourea.

The hematological effects of a single dose of 50 mg/kg Methylnitrosourea (MNU),administered i.v. to CBA/J mice, are described. Special emphasis was given to the number of pluripotent (CFUS) and granulocytic committed (CFUc) stem cells found in the bone marrow and spleen. In the peripheral blood a decreased number of reticulocytes, granulocytes, lymphocytes and thrombocytes was seen. This was followed by a rapid return of reticulocytes and a very slow return of thrombocytes. The bone marrow cellularity was below normal for at least 2 weeks with a markedly reduced number of lymphocytes. A rapid decrease in bone marrow and splenic CFUS and CFUc to 20-50% of control values was observed within 3 hours in mice injected with MNU. Seven days after MNU treatment, CFUS was about 10% of normal in both tissues. Contrary to this, CFUc had undergone significant regeneration. After 3 weeks CFUS returned to normal levels. At no stage could colony stimulating activity be detected in the serum.


Erythropoietin in renal and hepatic lymph of conscious ewes.

Spontaneously flowing fistulae were established in the efferent lymphatics of popliteal, prescapular and prefemoral nodes and lumbar trunk or in the afferent lymphatics draining the kidney and liver of sheep. Lymph was collected from these sites over various time intervals and assayed for erythropoietin (Ep) content. The objective of the study was to establish the anatomic site(s) of Ep production. Normal lymph did not contain detectable titers of Ep, nor did renal lymph or blood plasma from a sheep systematically treated with cobaltous chloride. Renal lymph did contain measurable levels of Ep following renal artery constriction, unilateral hydronephrosis or phenylhydrazine-induced hemolytic anemia. Phenylhydrazine treatment also produced elevated Ep levels in lymph from the liver but not in lymph efferent from either popliteal or prescapular nodes. These results indicate that Ep is generated primarily in the kidney and that the liver may be an extrarenal source of the hormone. The surgical techniques used in this study offer distinct advantages in examining the composition and physiology of lymph in sheep.


Phytohemagglutinin response of murine spleen cells during pregnancy and inhibition of normal phytohemagglutinin response by pregnancy or post-partum serum.

The in vitro blastogenic response of spleen cells to phytohemagglutinin-M (PHA) was evaluated as a measurement of the immunologic reactivity of virgin, pregnant and post-partum mice. In PHA-stimulated cultures 3H-thymidine incorporation by lymphocytes from post-partum mice was not significantly different from that of virgin age-matched control mice. Background 3H-thymidine incorporation was high in cultures from post-partum mice resulting in stimulation indices which were lower than those of virgin controls. Spleen cells from mice sacrificed after various intervals of pregnancy showed depressed PHA responsiveness only at the 15th day of gestation. The PHA response of normal spleen cells was depressed in the presence of serum from pregnant or post-partum mice.


Neuronal responses to eye muscle stretch in cerebellar lobule VI of the cat.

Extraocular proprioceptive input to cerebellar vermis, lobule VI, was investigated in cats under N2O analgesia by recording neuronal responses to eye muscle stretch. Both optic tracts were transected and the periorbital skin and conjunctiva were locally anaesthetized. Eye rotation within the physiological range was achieved by applying a pull of predetermined length and tension to each of the eight musculi recti at their insertion to the globe. Within lobule VI, only small patches of cortex receive stretch receptor afferents. The information made available by these afferents corresponds to a change of eye position. Minimal responses were dependent upon angular deflections of a few degrees. Maximal response amplitudes were obtained within the physiological range of angular deflections and angular velocities for the units tested. Most cells responded to stretch of more than one muscle. Three types of convergence were found: 1) neurons responding according to a certain direction of a conjugated movement of both eyes, 2) neurons responding to movements in either direction of one plane, 3) more complicated response patterns.


An analysis of response properties of spinal cord dorsal horn neurones to nonnoxious and noxious stimuli in the spinal rat.

Electrophysiological properties of neurones in the spinal cord dorsal horn were studied in decerebrated, immobilized spinal rats. Extracellular recordings were performed at the thoraco-lumbar junction level. Each track was systematically located by extracellular injection of pontamine sky blue. According to their responses to mechanical peripheral stimuli, cells were classified in four classes: Class 1 cells: Cells activated only by nonnoxious stimuli. They were divided into - 1A: hair movement and/or touch and 1B: hair movement and/or touch and pressure or pressure only. Class 2 cells: Cells driven by both nonnoxious and noxious stimuli, divided into - 2A: hair movement and/or touch, pressure, pinch and/or pin-prick, and 2B: pressure, pinch and/or pin-prick. Class 3 cells: Cells only activated by noxious stimuli (pinch and/or pin-prick). Class 4 cells: Cells responding to joint movement or pressure on deep tissues. Peripheral transcutaneous or sural nerve stimulation clearly showed that class 1 cells were activated only by A fiber input while 68% of classes 2 and 3 cells received A and C input. Histological examination indicated that cells driven only by noxious input were located either in the deepest part or in the marginal zone (lamina I) of the dorsal horn. Nevertheless, some lamina I cells were also driven by both nonnoxious and noxious stimuli. In addition, there is a great deal of overlap between class 1 and class 2 cells. This fact was confirmed by considering the wide distribution in the dorsal horn of cells receiving A and C input. However, spinal organization of the different classes of cells consists of a preferential distribution rather than a strict lamination. This study indicates that properties of dorsal horn inter-neurones in the rat have a high degree of similarity with those previously described in other species (cat and monkey).


Dark adaptation and receptive field organisation of cells in the cat lateral geniculate nucleus.

The receptive fields of LGN cells were investigated with stationary light and dark spot and annulus stimuli. Stimulus size and background intensity were varied while stimulus/background contrast was kept constant. The speed of dark adaptation vaired considerably from cell to cell. Dark adaptation made responses more sustained in all neurones and eliminated the oscillatory on-responses evoked under some conditions in the light-adapted cells. Dark adaptation led also to a disappearance of early phasic inhibition in on-responses, and increased response rise time and latency. The power of surround responses to inhibit centre responses decreased slightly at low levels of light adaptation in LGN cells but much less than in retinal ganglion cells. Some other traces of changing retinal surround effects also appeared inthe LGN on dark adaptation. For example, the functional size of receptive fields increased at low levels of illuminance as has been observed in retinal ganglion cells and the receptive fields as estimated from response peaks were larger than those estimated from sustained components.


Responses of cells in the cat lateral geniculate nucleus to moving stimuli at various levels of light and dark adaptation.

The responses of neurones in laminae A and A1 of the cat lateral geniculate nucleus to moving stimuli were investigated at different background luminances. Moving bright slits, dark bars and edges were employed; the contrast of stimuli against the background was held constant. Background intensities varied from 10(-3) to 10(2) td. Responses as stimuli passed across the centres of LGN receptive fields became stronger with increasing levels of light adaptation up to 10(-1)-10(1) td and then remained constant. Responses as stimuli passed through surround regions altered qualitatively with adaptation level, generally increasing in strength and complexity with background luminance. As a bright slit for on-centre cells or dark bar for off-centre cells left the surround, in almost all units a strong secondary peak could be elicited by an appropriate selection of the adaptation conditions. Many features of the responses to moving stimuli could not be predicted from the responses to stationary stimuli under different adaptation conditions described in the previous paper.


Commissural projection to the amygdala thourgh the fimbria fornix system in the cat.

Single shock stimulations have been applied stereotaxically and bilaterally in the region of the caudo-thalamic groove of the cat. These stimulations elicit diphasic potentials in the amygdala. Using combined methods of stimulation and lesion, it has been demonstrated that these electrical responses are due to the excitation of fibers projecting rostrally in the lateral border of the contralateral fimbria and caudally in the homologous part of the homolateral fimbria. A commissural path has been identified in the rostral part of the fimbria-fornix. Analysis of the experimental data has shown that the projection system consists of a discrete bundle of fibers which probably reaches the amygdala directly, in the dorsal part of the basal nucleus. The length of the explored portion of this pathway has been measured. The calculated conduction velocity of this amygdalopetal commissural component of the fimbria is 4.5 m/sec.


Effects of LSD on the response of single units in cat visual cortex.

The effects of intravenous doses (200 mug) of LSD on the activity of single neurones in the primary visual cortex have been studied in cats anaesthetized with urethane. Cells were stimulated with a bright bar of light moved over the receptive field, and orientation tuning was assessed quantitatively before and after administration of the drug. Changes in neuronal activity were compared with those observed in a control sample of cells recorded when the cats were given no drug. LSD increased the responsiveness of some cells to visual stimuli and decreased that of others, but some cells were not affected. The changes in responsiveness were dose dependent; the larger doses of the drug (expressed in mug/kg body weight) tended to depress the responses and the smaller doses to enhance them. The effects appeared earlier in complex cells than in simple cells. Changes in spontaneous activity, direction selectivity and orientational properties were found in some cells.


Bilateral simultaneous tubal pregnancies after ovulation induction with clomiphene-menotropin combination.

A case is presented of bilateral simultaneous tubal pregnancy after ovulation induction with a clomiphene-menotropin combination. Although extremely rare in the general population, the entity of simultaneous pregnancies is far more common with ovulation induction. Care must be taken not to mistake an extrauterine pregnancy for a hyperstimulated ovary.


Conservative management of a pituitary tumor during pregnancy following induction of ovulation with gonadotropins.

Ovulation induced with human menopausal gonadotropin-human chorionic gonadotropin in a 27-year-old woman who had been amenorrheic for 7 years resulted in pregnancy. Although pretreatment neurologic evaluation was normal, significant loss of vision was found at 30 weeks' gestation, and a skull x-ray revealed enlargement and erosion of the sella turcica. As an attempt to delay surgery, 12 mg of dexamethasone daily arrested further visual deterioration, and the pregnancy continued uneventful for 36 weeks, when triplets were born. Five days after delivery the visual fields were normal. Trans-sphenoidal resection of a prolactin-secreting chromophobe adenoma of the pituitary was carried out 6 months later. It is suggested that when disturbance in visual perception due to a pituitary tumor occurs during pregnancy, a course of high-dose corticosteroids with frequent monitoring of visual fields and acuity might be tried before surgical intervention. Although further rapid deterioration in vision may dictate immediate surgical decompression, conservative management may result in stabilization, allowing the patient to carry the pregnancy to term and obviating the need for emergency surgery.


Human cervical mucus. II. Changes in viscoelasticity during the ovulatory menstrual cycle.

Quantitative viscoelasticity measurements were made on individual human cervical mucus samples by microrheometry. Increases in mean values for mucus spinnbarkeit, ferning, and wet weight were associated with the ovulatory phase of the menstrual cycle, while no significant differences versus time were noted for mean values for sample pH or nondialyzable dry weight. A nadir in mucus nondialyzable solids (NDS) concentration and in visoelasticity was seen at or near midcycle. Substantial, highly reproducible, variations in mucus viscoelasticity were observed when mucus from different donors was compared. When the contribution of (NDS) to viscoelasticity was minimized by data normalization or by sample reconstitution, a significant increase in viscoelasticity was associated with the ovulatory phase of the cycle, suggesting the occurrence of a relative increase in mucin concentration or a compositional change in the mucus.


Human cervical mucus. III. Isolation and characterization of rheologically active mucin.

Several common mucolytic agents were screened for their ability to solubilize cervical mucus without incurring irreversible losses in mucus viscoelasticity. Sodium thiocyanate was selected on the basis of its effectiveness and handling convenience, and solubilized mucus was fractionated by gel filtration on Sepharose columns. The excluded mucin fraction was characterized by a high neutral hexose to protein ratio and contained all of the elasticity of thiocyanate-treated whole mucus. The concentration of mucin in individual mucus samples collected throughout the ovulatory menstrual cycle was determined from column elution profiles. An increased relative amount of mucin was associated with samples collected during the ovulatory phase of the cycle, and a strong correlation was obtained when the percentage of mucin in individual samples was plotted against their respective storage moduli. These results indicate that the cyclic fluctuations in mucus viscoelasticity seen previously at constant concentrations of nondialyzable solids can be attributed to variations in mucin concentration. Evidence was also obtained, however, for compositional differences in mucus derived from different patients.


Tubal reanastomosis by microsurgery.

The enormous increase in the number of sterilizations performed in young women is creating a demand for reversal of this procedure. The author's experience with tubal reanastomosis using a microsurgical technique is presented. The traditional approach to cornual occlusion of the tubes has been tubouterine implantation. The demonstration that in such cases the intramural portion of the tube is often patent and that the occlusion site is located in the proximal isthmus has allowed, instead, resection and end-to-end anastomosis at the cornua. Including both tubouterine anastomosis for cornual occlusion and end-to-end anastomosis after previous sterilization, tubal reanastomosis was performed in 31 patients. The postoperative patency rate was 87%, and 64% have had intrauterine pregnancies. In the group subjected to tubal reanastomosis following a previous sterilization, 72.7% of those attempting a pregnancy and having more than 6 months' follow-up have had intrauterine gestations.


Failures following fimbriectomy.

From 1970 through 1973, 388 bilateral fimbriectomies were performed. By the end of 1974, seven pregnancies had occurred, and in four of these patients a resterilization laparotomy was performed. All four cases showed a unilateral tuboperitoneal fistula. These fistulas were examined and compared morphologically with congenital tuboperitoneal fistulas. This proved that all four fistulas were acquired and that they were probably caused by the catgut ligatures used for ampullary ligation. The rather frequent occurrence of hydrosalpinx after fimbriectomy is mentioned. Finally, it seems of questionable advantage to resect the infundibulum as part of a fimbriectomy using the three-ligature technique.


Perfect anatomical reconstruction of vas deferens with a new microscopic surgical technique.

Early results with a new, two-layer microscopic technique for anastomosis of the vas deferens, using an operating microscope and ultrafine suture, reveal that patency of the vas deferens can be achieved in virtually every case. Normal sperm counts can be achieved in up to 95% of patients. Failure with conventional techniques is usually due to continuing partial obstruction. A poor sperm count after this technique is most likely due to an inherent inability of the patient to produce normal sperm, a likely sequela of chronic obstruction. Thus, while success is also good 10 years after vasectomy, it is not as predictable. Previous failure with a conventional operation does not limit success with a reoperation using the microscopic two-layer tehcnique. Operations on 200 patients since this original study are confirming these early results.


The effects of prostaglandins on sperm motility.

Inflammatory exudates around intrauterine devices were found to produce large concentrations of prostaglandin F2alpha. To evaluate the effect of this substance, 100 semen specimens were incubated in concentrations 100 times greater than that found in normal semen. Motility indices were calculated, and significant inhibition of sperm motility was found. The effect of prostaglandin E on sperm motility is also reviewed. The physiology of prostaglandins and their mechanism of action via the cyclic nucleotide system are discussed.


The role of prostaglandins in the spontaneous motility of the fallopian tube.

Spontaneous isometric contractions of the human fallopian tube were measured in vitro. The tubes were obtained during the follicular phase of the menstrual cycle in 16 experiments and during the luteal phase in 23 experiments. The area under the curve and the frequency of spontaneous isometric contractions, together with the amount of prostaglandins E and F produced by the tube, were measured. Using each tissue as its own control, the effects of adding indomethacin or papeverine to the tissue both were assessed. Indomethacin, a prostaglandin synthetase inhibitor, significantly reduced the prostaglandin output without affecting the tubal motility. By contrast, papaverine, which is a smooth muscle relaxant but not an inhibitor of prostaglandin synthesis, significantly reduced both motility and prostaglandin output. It is concluded that prostaglandins do not have a direct role in the regulation of the spontaneous motility of the human fallopian tube.


Effect of ovulation and hormonal treatment on the in vitro response of rabbit oviducts to prostaglandins E1 and F2alpha.

Rabbit oviductal circular muscle isometric contractile response was measured in relation to treatment with prostaglandin E1 (PGE1) and prostaglandin F2alpha (PGF2alpha). PGE1 (1 mug/ml) inhibition of the contractile response of the rabbit oviduct to field stimulation was increased in the proximal isthmus after ovulation. Estrogen and progesteron, in doses known to alter ovum transport, did not affect the response of the oviduct to PGE1. In comparison to the response of estrous tissues, the stimulatory effect of PGF2alpha on the isthmus was decreased 24 hours after administration of human chorionic gonadotropin (HCG). Treatment with estrogen and progesterone did not affect these postovulatory changes. The response of the ampullary-isthmic junction to PGF2alpha was significantly reduced 72 hours after administration of HCG. Neither ovulation nor steroid treatment affected the response of the ampulla to PGF2alpha. Changes in the sensitivity of the oviduct to prostaglandins after ovulation may be necessary for successful ovum transport.


Endometriosis and infertility: an enigma.

In our efforts to overcome infertility and subjective complaints in young women with endometriosis, we have performed conservative surgical procedures upon 142 women 30 years of age or less. In these women, multiple endometriomata were resected from the pelvic peritoneum, one or both ovaries, the large and small bowel, and the appendix. In addition, uterine and ovarian suspension, bowel resection, appendectomy, myomectomy, and presacral neurectomy (PSN) were performed when indicated. Conception occurred in 70% of the women wishing to conceive; the highest rate was found among those who had developed endometriosis after a previous conception. Ovarian involvement seemed to reduce the conception rate by 10%. Uterine suspension and PSN did not affect conception but did provide a symptomatic relief. We conclude that early examination for endometriosis and aggressive surgical management is indicated in young women with demonstrable disease.


The role of the psychiatrist in a reproductive biology clinic.

The psychiatrist consulting to an infertility clinic is confronted with a variety of clinical issues and problems. The couple arrives with anxiety, for a work-up that in itself will be traumatic. The psychiatrist's role is to weed out distortions and issues that are unreal. Psychosexual and marital conflicts may also masquerade as an infertility problem. The simplest manner in which psychologic factors can be thought of as causing infertility is through their effect on sexual performance. Brief therapeutic techniques include education, encouragement, and behavioral techniques to improve performance. Psychoanalytically oriented techniques include relating the symptom to unconscious conflicts stemming from the past and understanding the secondary gain of the symptom. The psychiatrist's role may also involve helping the couple to deal with the outcome of the infertility work-up, including helping the couple to mourn the fact that they cannot have children, assisting in decisions involving artificial insemination and adoption, and helping the couple to deal with uncertainty when no definite cause for the infertility has been discerned. The multiplicity of possible psychologic interventions requires the psychiatrist to be ubiquitous. In the light of this, a number of suggestions are listed as to how a psychiatrist might best be utilized.


Artificial insemination homologous and its role in the management of infertility.

Fifty-seven cases of homologous artificial insemination (AIH) were reviewed as well as the reason for performing the insemination. Three patients had AIH because of impotence, and two conceived. Twenty-nine patients whose husbands had sperm counts of less than 40 million/ml had AIH combined with split ejaculates, and seven (24.1%) became pregnant. Twenty-five patients had AIH because of persistent, unexplained, poor postcoital tests despite a normal semen picture, and eight (32%) became pregnant.


Plasma progesterone in women with a history of recurrent early abortions.

Basal body temperature, vaginal hormonocytology, and plasma progesterone concentrations were studied serially in consecutive menstrual cycles of 8 normal subjects and of 10 patients with a history of recurrent early abortions. The menstrual patterns and characteristics of basal body temperature of the patients did not differ significantly from those of control subjects. The mean plasma progesterone concentrations at the midluteal phase of the study cycles of three patients were below those of the lower limit of the control group (4 ng/ml). The results of this study support the conviction that an inadequate luteal phase is more likely to occur in women with a history of recurrent early abortions.


Short-term effects of norethisterone oenanthate and medroxyprogesterone acetate on glucose, insulin, growth hormone, and lipids.

The effects on carbohydrate and lipid metabolism in 24 healthy female subjects of the long-acting steroid contraceptives norethisterone oenanthate (200 mg) (11 subjects) and depo-medroxyprogesterone acetate (150 mg) (13 subjects) were studied. The subjects were between the ages of 18 and 25 years, with a history of normal menstrual periods. Pretreatment levels of plasma cholesterol, plasma triglycerides, phospholipids, blood glucose, insulin, and growth hormone were compared with those obtained 3 weeks and 12 weeks after the initial injections. There were no statistically significant differences from the pretreatment levels in any of the values obtained at 3 weeks and 12 weeks in either group.


Glycogen estimation by a rapid enzymic method in very small samples of human endometrium: glycogen content in the endometrium of infertile patients during the menstrual cycle.

An enzymic method using alpha-glucosidases was adapted for measuring glycogen in very small samples (3 mg) of human endometrium. The method is useful as a clinical test of the physiologic function of human endometrium. The glycogen content of the endometrium of normal and infertile patients was measured during the menstrual cycle. The maximal content in both groups was observed between the 16th and 23rd days of the cycle, but the glycogen content of the infertile group was significantly lower (P less than 0.005). These results confirm the reports of others. Endometrial glycogen and urinary pregnanediol levels in 32 infertile patients were measured on day 7 after ovulation. The glycogen content of the endometrium of 21 of these patients, who showed normal excretion of urinary pregnanediol (greater than or equal to 2 mg/day), was significantly higher than that of the other 11 patients who showed low excretion of urinary pregnanediol (less than 2 mg/day) (P less than 0.005). This finding suggests that there is a high correlation between the function of the corpus luteum and endometrial glycogen deposition.


Radioreceptorassay of luteinizing hormone-human chorionic gonadotropin in urine: detection of the luteinizing hormone surge and pregnancy.

A radioreceptorassay of luteinizing hormone (LH)-human chorionic gonadotropin (hCG), using plasma membranes of bovine corpora lutea, has been extended to the detection of the midcycle LH peak and subsequent pregnancy in morning and 24-hour urine samples on days 10 to 12 following ovulatiobjects as determined by radioreceptorassay and radioimmunoassay were 45 ng and 20 ng/ml of urine, respectively; in 24-hour urine samples, mean levels of 39 ng and 17 ng of LH/ml, respectively, were found. A sustained rise in hCG was detected by the radioreceptorassay from 10 to 12 days after conception, and by day 15 the hCG levels were in the range of the midcycle LH range; this finding was confirmed by the radioimmunoassay of hCG.


Effect of caffeine on increasing the motility of frozen human sperm.

A preliminary report on the effect of the addition of caffeine to 45 frozen sperm samples, in order to restore the effectiveness and motility of frozen stored human sperm, is presented. The addition of 7.2 mM caffeine proved optimal and resulted in 40% to 80% increased sperm motility after 30 days of frozen storage. The use of rapid-rate freezing to produce frozen sperm pellets and the addition of one frozen pellet of buffered caffeine (7.2 mM) to five sperm pellets before thawing are recommonded. For slow-rate freezing in paillettes, the addition of a caffeine solution (final concentration, 7.2 mM) to the sperm and protective medium is recommended. With these methods, frozen storage of hypomotile sperm, which previously could not be preserved by freezing, is now practical.


Metabolic effects of unilateral orchiectomy on the guinea pig testis.

Six months after unilateral orchiectomy, there was a significant increase in the RNA and DNA content of contralateral testes as compared with the testes of age-matched normal guinea pigs. The ratio of RNA to DNA was not affected by orchiectomy, suggesting that the compensatory growth was secondary to hyperplasia rather than hypertrophy. Tritiated thymidine uptake by the contralateral testis was elevated at 2 weeks and 2,4 and 6 months after orchiectomy, confirming that increased metabolic activity occurred in the remaining testis after hemicastration.


In vivo sodium, potassium, and sperm concentrations in the rat epididymis.

In vivo samples of epididymal fluids were obtained through the use of micropuncture techniques. Microsamples from four areas of the rat epididymis were analyzed for Na+ and K+ concentrations and for sperm density. Na+ values declined significantly from caput to corpus epididymidis (P less than 0.01), while K+ and sperm concentrations increased significantly (P less than 0.01). A large water loss from the epididymal lumen was calculated, as well as net losses of both cations. Water losses may be explained on the basis of an active Na+ pump; however, the effect of the absolute values of epididymal Na+ and K+ concentrations on sperm motility and fertility remains unresolved.


Effects of sonication on mature rat testes.

Exposure of rat testes to high-frequency sound waves temporarily interrupted the spermatogenic process. Rats treated with 1 watt/sq cm for 10 minutes exhibited a degeneration of advanced germinal cells and were incapable of impregnating females for 150 days. Forty-eight hours after sonication, spermatocytes and spermatids developed irregular membranes and released their contents into theinterstitium. Spermatogonia, Sertoli cells, and Leydig cells appeared normal, and no genetic anomalies could be detected in the progeny of treated animals. It was hypothesized that the reduction in sperm count was due to changes in membrane permeability which produced conditions unfavorable to maturation of testicular cells.


Cytogenetic studies in primary infertility.

Chromosome studies were conducted on 117 men with primary infertility (54 with oligospermia and 63 with azoospermia) and 25 fertile volunteers who acted as controls. No chromosomal abnormalities were observed except for nine cases of Klinefelter's syndrome. From this study, it is apparent that chromosomal abnormalities other than Klinefelter's syndrome are not etiologic factors in the infertility of oligo- or azoospermic men.


[Architectonics of the arterial bed and blood flow in the lungs of frogs].

In morphometric studies of arteriolar branching of the frog lung with determination of the blood flow rate and its distribution, the diameter of the trunk was shown to lay between 16 and 350 mcm. The law of variation (in connection with the diameter range) and the specific features of interrelationship between some structural characteristics of the vascular branching were revealed. Analysis of the data obtained in vivo showed that the morphofunctional characteristics of the arteriolar branches in the frog lung corresponded to the theoretical "minimum work" model.


[Efferent link of cardiac reflexes with carotid labyrinth receptors in the frog].

In frongs, changes of sympathetic and parasympathetic discharges were studied in the structures of the efferent link of the cardial reflexes from carotid chemoreceptors. Both the acid and the alkaline fluids perfused through the carotid labyrinth considerably decrease the sympathetic and increase the parasympathetic discharges in the cardial branches of the vago-sympathetic trunk. Cerebral portions above the medulla oblongata exert no essential effect on the specific features of reflex changes of the efferent activity in the vago-sympathetic trunk. After separation of the medulla oblongata from the spinal cord, the sympathetic discharges do not change in response to stimulation of carotid receptors while the alteration of parasympathetic activity holds on.


[Resistance of cortical neurons to oxygen deficit].

Polymicroelectrode recording of spontaneous activity of somatosensory cortical neurons in cat showed that, during asphyxia, the spike activity of 2-3 neurons reocrded with one microelectrode usually ceased simultaneously. The distance between microelectrodes being 50-200 mkm, the difference in time of survival was significant. Neurons of the visual cortex were more resistant that those of the somatic cortex. The different resistance of neurons against asphyxia is supposed to be due to different microcirculation and different polarization of neuronal membranes.


[Interaction between spindles evoked by electric stimulation of different regions of the cerebral cortex].

In unanesthetized immobilized cats, under repeated administration of small doses of nembutal (2-3 mg/kg), connections between the projection and the parietal associatition cortical areas was studied as well as the interaction between spindles elicited by stimulation of these areas. Stimulation of the primary sensory areas (auditory or somatosensory) was shown to be able to elicit spindles not only in the stimulated area but in the association cortex too. This latter spindle, being kind of induced from the sensory areas, interacts with the spindles elicited by the direct electrical stimulation on the association cortex.


[Response of neurons of the anterior and posterior regions of the hypothalamus to stimulation of the vagus and sciatic nerves and photic stimulation].

Evoked activity of single units in anterior and posterior hypothalamus to vagal, sciatic nerves, and photic stimulation was studied in anesthetized and immobilized cats. The responsiveness of neurons of the posterior hypothalamus was 66, 77 and 37% to vagal, sciatic nerves and photic stimulation, respectively, and of the anterior hypothalamus -- 47, 62 and 48%. Vagal stimulation was found to be the more effective for units of the posterior hypothalamus. Responses of units to a flash prevailed in the anterior hypothalamus. 78% of convergence of viscero-somatic afferentation on neurons of the posterior hypothalamus and 62% -- on anterior hypothalamic neurons, were revealed. The responses to all kinds of afferent stimuli were phasic and of excitatory character. Possible role and mechanisms of vagal interoceptive activation of hypothalamic units are discussed.


[Rhythmic activity of individual elements of the isolated carp retina].

At the level of photoreceptor, bipolar and ganglion cells of the carp isolated retina displayed intracellular oscillations of two types: with frequency of about 6-12 Hz, continuously generated in darkness, suppressed by light and slowly recovering, and oscillations with frequency of about 20-50 Hz, observed during swithching on and off of light. The latter are components of responses to light of bipolar, amacrine, and ganglion cells. Possible role of different structures of the retina in generation of rhythmic potentials, and their functional significance are discussed.


[Noradrenaline-H3 uptake by isolated rat organs with active and blockaded adrenoreceptors].

The beta-adrenoreceptor blocking agent propranolol was shown to activate noradrenaline-N3 absorption by the rat isolated organs by 30-180%. The alpha-adrenoreceptor blocking agent phentolamine only activated by 30-55% the noradrenaline-N3 absorption in the organs possessing the postsynaptic alpha-adrenoreceptors (ductus semen, spleen and amsll intestine). The beta-adrenoreceptor activator isopropylnoradrenaline decreased the intensity of noradrenaline-N3 absorption in all the organs by 15-50%. The alpha-adrenoreceptor activating agents (urine and mesaton) only depressed the noradrenaline-N3 absorption by 20-45% in the organs possessing postsynaptic alpha-adrenoreceptors. The data obtained suggest existence of reverse transsynaptic regulatory effects via adrenoreceptors of the cell-effector on the processes of noradrenaline absorption by adrenergic neuron.


[Bioelectrical activity and automatic properties of different parts of a two-chambered heart].

Two pacemakers localized in sinoatrial and atrioventricular valves were revealed in the tench heart. In their absence, the ventricular and sometimes the atrial myocardium are capable of initiating the automaticity. Pacemaker's cells of the sinoatrial valve are surrounded by specific area similar to sinoauricular ring in amphibia or sino-caval region in mammals. Characteristics of the action potential in different parts of the tench heart are presented.


[Vasomotor reactions of the pulmonary circulation upon hypothalamic stimulation].

The blood flow in the lung lobe perfused under constant pressure was recorded with photoelectric drop recorder in acute closed-chest experiments in anesthetized dogs. Stimulation of supraoptic and lateral mamillary nuclei in most cases decreased flow rate and increased vascular resistance in perfused pulmonary lobe, while stimulation of sympatho-inhibitory area exerted opposite effect. Bilateral vagotomy and administration of atropin and inderal did not block the lesser circulation responses to the hypothalamic stimulation. However, phentolamine and bilateral ablation of stellate and upper thoracic ganglia eliminated chnages of blood flow and vascular resistance in the perfused lobe. The data obtained suggest that stimulation of some hypothalamic areas evoke obvious vasomotor responses in the lesser circulation and that these responses occur mainly through alpha-adrenergic sympathetic innervation of pulmonary vessels.


The effect of cortisone on protein breakdown and synthesis in rat skeletal muscle.

The effect of cortisone administration on the rates of muscle protein breakdown and synthesis has been studied in the rat extensor digitorum longus muscle. Cortisone acetate (100 mg/kg body weight/day) was administered intraperitoneally for 1--3 days. Muscle wieght and protein content were significantly reduced by cortisone administration. Rates of protein breakdown were measured by tyrosine release from the isolated muscle into the intracellular pool and medium during a 2-h incubation with cycloheximide to block protein synthesis. Rates of protein synthesis were assayed by [14C]tyrosine incorporation into protein of the isolated muscle during a 2-h incubation. Cortisone administration inhibited significantly the rate of protein synthesis after 1--3 days treatment and also reduced significantly the rate of protein breakdown per muscle after 3 days treatment. The synthesis of myofibrillar and soluble proteins was affected to the same extent. These results strongly suggest that the effect of cortisone administration on muscle protein is mainly through its inhibition of protein synthesis rather than through an acceleration of protein breakdown.


Partial reduction with dithiothreitol of disulfide bonds in human chorionic gonadotropin.

Of the eleven disulfide bonds of human chorionic gonadotropin (hCG), two were reduced with a 10-fold molar excess of dithiothreitol (DTT) relative to hormone. An S-carboxymethyl (SCM) derivative and a reoxidized product of this reduced hCG retained full biologic activity and were likely to be immunologically identical with native hCG. These two disulfide bonds appeared to be located in the alpha-subunit of the hormone. A 40-fold molar excess of DTT was required to reduce the third disulfide bond which was located in the beta-subunit. An SCM derivative ot this hexa-SH-hCG was only one fifth as biologically active as native hCG but its immunologic activity was only slightly decreased. However, its reoxidized product exhibited over 70% of the biologic activity of and it had nearly the same immunologic activity as the hormone. Reduction of a fourth disulfide bond, probably in the beta-subunit, by a 100-fold molar excess of the reagent was accompanied by considerable alterations in the hormone conformation as evidenced by electrophoresis. The resulting SCM derivatives as well as reoxidized products showed progressive decreases in biologic and immunologic activity and both reduced deca-SCM-hCG and a reoxidized product of deca-SH-hCG were virtually devoid of biologic activity. These findings suggest that the two first-reduced disulfide bonds, apparently in the alpha-subunit, are not important to the biologic activity of the hormone and that the third-reduced disulfide bond, probably in the beta-subunit, is very important in maintaining a biologically active conformation of the hormone. Further disulfide reduction appears to result in considerable alterations in the general conformation of the hormone, including disulfide interchange.


Effect of testosterone propionate on ABP levels in rats hypophysectomised at different ages using individual sampling.

The effect of age at hypophysectomy on the response of the regressed rat testis to testosterone propionate (TP) and FSH with respect to androgen-binding protein (ABP) levels was studied in individual animals. All treatments were begun 30 days after surgery. Treatment of rats 35, 45, 55 and 75 days of age at surgery with TP (1 mg/260 g for 25 days) significantly increased the level of ABP in the testes of animals in all age groups except those hypophysectomized at 35 days of age. TP treatment did not significantly elevate epididymal levels of ABP above those found in untreated rats in any age group. In animals hypophysectomized at 100 days of age, acute treatment (3 days) with FSH (150 and 300 mug/day) significantly increases the ABP levels per testis and per epididymis. Similar treatment with 750 mug TP/day did not result in a statistically significant increase in testicular ABP. No synergism between the two hormones was noted under the conditions described. Significant restoration of testicular ABP levels per mg protein was achieved with 1 mg TP/day by 5 days of treatment. Treatment of hypophysectomized adult rats with FSH raised the epididymal/testicular ratio of ABP to about 40% of that found in intact rats while comparable treatment with TP (750 mug/day for 3 days or 1 mg/day for 10 days) only slightly affected the ratio. It is postulated that FSH may facilitate ABP transport to the epididymis in addition to affecting its production by the testis.


Human somatomedin A and longitudinal bone growth in the hypophysectomized rat.

A somatomedin A preparation, when given at total doses of 14 and 70 U did not increase the longitudinal bone growth in hypophysectomized rats. Growth hormone (WHO) significantly increased the longitudinal bone growth.


The effects of sex-steroids on the synthesis of uterine non-histone proteins.

Newly synthesized non-histone proteins (NHP) labelled with [35S] methionine were isolated from uterine epithelium and stroma after different hormone treatments and examined by isoelectric focusing in polyacrylamide gels. Progesterone increased the proportion of basic NHP in the epithelium. This effect was detectable within 4 h and was maintained unchanged after oestrogen stimulation, which increased the synthesis of all classes of NHP. The proportion of basic NHP was higher in the untreated stroma than in the epithelium. Progesterone pretreatment did not increase the proportion of basic NHP in the stroma but prevented the increase in the more acidic NHP which followed treatment with oestrogen alone. The tendency to synthesize a higher proportion of basic NHP did not in any way correlate with the tissue's proliferative status.


Evidence that abnormal myoelectrical activity produces colonic motor dysfunction in the irritable bowel syndrome.

Although the irritable bowel syndrome is characterized as an abnormality in colonic motor activity occurring in response to certain stimuli, the etiology of this disorder is unclear. The purpose of this study is to determine the relationship of altered slow wave activity and the abnormal motility of the distal colon seen in patients with the irritable bowel syndrome. Myoelectrical activity was recorded using a bipolar electrode clipped to the distal colonic mucosa and motor activity was measured by perfused catheters. Colonic slow waves and contractions were present at two frequencies, 6 and 3 cycles per min. The slow wave frequency seemed to determine the frequency of colonic motor activity. Patients with the irritable bowel syndrome had increased 3-cycle per min slow wave activity in the basal state (P less than 0.001). However, no difference in basal 3-cycle per min motor activity was present between the two groups (P greater than 0.05). When colonic motor activity was increased with cholecystokinin or pentagastrin, patients with irritable bowel syndrome showed a marked increase in 3-cycle per min contractile activity, occurring simultaneously with 3-cycle per min slow wave activity. These studies suggest that increased colonic 3-cycle per min slow wave activity in patients with the irritable bowel syndrome may be the basic abnormality that leads to colonic motor dysfunction in response to various physiological stimuli.


Regional intestinal blood flow in ulcerative colitis and Crohn's disease.

By means of a recently developed isotope washout technique, regional intestinal blood flow and its intramural distribution were determined during surgery and correlated to the morphological inflammatory and vascular features of ulcerative colitis (UC) and Crohn's disease (CD) at different stages and location. In severe colitis total blood flow was significantly increased (64 +/- 9 ml per min X 100 g; mean +/- SE; n = 13) both in UC and CD, the mucosal-submucosal blood flow amounting to 121 +/- 25 ml per min X 100 g (n = 7). The muscularis blood flow was within normal range (18 +/- 10; n = 7), however. In chronic long-standing quiescent or inactive UC, in "healed colitis," and in chronic segmental colitis (CD), colonic blood flow was normal or even reduced (13 +/- 2; n = 8), the decrease in flow comprising both the mucosa-submucosa (21 +/- 3; n = 3) and the muscularis (7 +/- 3; n = 3). In early exudative stage of CD in the ileum total blood flow was normal (26 +/- 5; n = 7) with a normal mucosal-submucosal blood flow (35 +/- 5; n = 3). In late fibrosing stage total blood flow was reduced (11 +/- 1; n = 6) as was the mucosal-submucosal flow (10 +/- 4; n = 3). The muscularis blood flow was reduced in both these stages of ileal CD (7 +/- 1; n = 6). There was a satisfactory agreement between the obtained blood flow figures and the morphologically observed vascular pattern.


Studies of the duodenal and fecal flora in gastrointestinal disorders during treatment with an elemental diet.

The duodenal and fecal flora were studied in 18 patients suffering from gastrointestinal disorders during treatment with an elemental diet (Vivasorb). Before treatment the duodenal flora was found to be abnormal in 6 of 17 patients. After treatment the flora remained abnormal in 2, whereas, it became normal in 4 patients, 3 of whom were suffering from ulcerative colitis. The fecal flora was uninfluenced by the diet. The overall number of colonies per gram of dry feces did not vary significantly, whether anaerobic or aerobic. The ratio of anaerobes to aerobes was significantly changed in only 3 patients. There was no correlation between changes in the duodenal and the fecal flora, on the other hand, and the final clinical result of treatment with elemental diet on the other hand. On an average, daily fecal output remained unchanged. In several cases the volume either increased or decreased, but the fecal flora was unchanged. The findings are in agreement with those made in most of the earlier studies of healthy volunteers and in one study of a patient who was suffering from ulcerative colitis.


Invasion of small intestinal mucosa by Giardia lamblia in man.

The mucosal biopsies from duodenum and jejunum of 31 patients showing Giardia lamblia in their feces were studied histologically. Although the trophozoites were found in all the biopsy specimens in the luman, the tissue invasion by the parasites in different stages, from their entry through the epithelium to the lamina propria could be demonstrated in 12 of them, all of the latter having diarrhea and steaterrhea. Varying histological changes in jejunal mucosa were also observed in 9 cases, of which 7 showed mucosal invasion by giardia trophozoites. In 17 of the series neither tissue invasion by the parasite nor mucosal change could be found.


Estimation of fat absorption from single fecal specimens using 131I-triolein and 75Se-triether. A study in rats with and without induced steatorrhea.

The simultaneous use of 131I-triolein and 75Se-triether, a nonabsorbable marker, in a single oral dose to estimate fat absorption from incomplete fecal collections was tested in rats with and without induced steatorrhea. The results in normal rats showed that analysis of single stool samples allows a valid estimate of fat absorption as defined by the balance study based on the total fecal recovery of 131I. However, in the few normal rats with poor absorption, the absorption values from successively excreted stools showed a tendency to increase. Similar findings were obtained from biliary fistula rats with marked steatorrhea. No evidence of different intestinal transit rates of test fat and marker was observed in bile-diverted rats, thus suggesting that the observed inconsistency in fat absorption values from different stool specimens reflects intraprandial differences in the absorption of fat. Studies on rats subjected to intestinal ischemia do not support the suggestion of others that separation of fat and triether will occur if a mucosal defect is involved as the cause of fat malabsorption. It is concluded that this dual isotope technique may be of value in the clinical estimation of fat absorption, as it offers important technical advantages over conventional fat balance studies.