Activity of 2-(5-methyl-4-imidazolyl)-ethylamine (5-methylhistamine) on the gastric secretion of different laboratory animals and of man

The compound 2-(5-methyl-4-imidazolyl)-ethylamine, namely 5-methylhistamine3(5-MeH), was compared to histamine for its stimulant activity on gastric secretion in Heidenhain pouch dogs, cats, rats and also on gastric secretion of human volunteers.In dogs and cats 5-MeH had approximately the same activity as histamine, both as regards threshold doses and peak secretory effects, when given by subcutaneous injection or by intravenous infusion.In the rat 5-MeH was 60% less active than histamine when given by either i.v. injection or infusion.In the preliminary experiments carried out in man, 5-MeH and histamine given at the same doses had approximately the same effect as regards volume, acidity of the gastric juice and also persistence of effect. 5-MeH was tolerated in all the subjects whereas histamine was not tolerated in 1 out of 5 subjects.The results obtained suggest that this new methyl derivative could reprent a good alternative to thmmon stimulants used in the clinical gastric secretory tests.