betazole betazole betazole (also known as ametazole) is a histamine h2 receptor agonist. betazole hydrochloride is known as gastramine and histalog. not to be confused with betaxolol, a selective β1-adrenergic receptor antagonist. betazole names iupac name 2-(1h-pyrazol-5-yl)ethan-1-amine identifiers cas number 105-20-4 y 3d model (jsmol) interactive image chebi chebi:59170 y chembl chembl1201323 n chemspider 7455 y drugbank db00272 y echa infocard 100.002.981 iuphar/bps 7126 pubchem cid 7741 unii 1c065p542o y comptox dashboard (epa) dtxsid7022675 inchi inchi=1s/c5h9n3/c6-3-1-5-2-4-7-8-5/h2,4h,1,3,6h2,(h,7,8) ykey: jxdfeqonerdkss-uhfffaoysa-n yinchi=1/c5h9n3/c6-3-1-5-2-4-7-8-5/h2,4h,1,3,6h2,(h,7,8)key: jxdfeqonerdkss-uhfffaoyay smiles n1ccc(1)ccn properties chemical formula c5h9n3 molar mass 111.145 g/mol pharmacology atc code v04cg02 (who) except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). n verify (what is yn ?) infobox references it has been used as a gastric stimulant to test for maximal production of gastric secretion activity. the test can be used in diagnosis of diseases such as zollinger-ellison syndrome where there is excess acid production, in this case driven by over production of gastrin. the volume of acid secretion is measured following administration of betazole, diagnosis being secretion greater than 60% of the maximal acid secretion following betazole stimulation. this procedure can lead to complications and should be avoided in subjects with coronary artery disease. it is also used in diagnosis of gastritis in association with a test for secretin activity. betazole is used as a stimulant in preference to histamine because of its specificity for the h2 receptor and its advantage of not generating the undesirable side effects that histamine would induce. it therefore does not require concomitant use of antihistaminic compounds to block the actions of histamine at other histamine receptor types. it is used to test the effectiveness of h2 receptor blocking drugs such as nizatidine.