Effect of Some Imidazoles on Gastric Secretion.

Abstract

Histamine and pilocarpine are imidazoles which are known to stimulate gastric secretion.

Since gastrin preparations give a strong Pauly reaction and produce a number of the pharmacological effects of histamine, the question of the identity of histamine and gastrin has been raised 1 although some differences in the chemical properties of gastrin preparations and histamine are known to exist. 2 Koch, Luckhardt and Keeton 2 concluded from their work that gastrin appears to be a basic imidazole derivative. They studied the effect of 3 imidazole derivatives, namely, histidine, methylimidazole HCl and hydroxymethylimidazole HCl, on gastric secretion with negative results. Ivy and Javois 3 found also that histidine subcutaneously did not stimulate gastric secretion. Because of these facts we thought that it would be worth while to study the effect of other imidazoles on gastric secretion.

Professor Rose of the University of Illinois supplied us with imidazole proprionic acid, imidazole aldehyde, d-imidazole lactic acid and imidazole acrylic acid. Professor Hurd of Northwestern University supplied us with imidazole.

These imidazole derivatives were injected subcutaneously into 3 Pavlov pouch dogs a number of times in doses of from one to 5 mg. with negative results. Larger amounts were not used because Burgess, Sacks and Ivy 4 have had gastrin preparations which were active in less than 0.5 mgm. doses.

These 5 imidazoles were also injected intravenously in dogs prepared for recording blood pressure changes. None of them in from one to 5 mg. doses had any effect on blood pressure.

It is interesting that β-imidazole ethylamine HCl is a very potent excitant of gastric secretion, whereas imidazole and the ethylamine HCl 3 are inactive.

Conclusion. Imidazole, imidazole proprionic acid, imidazole aldehyde, 1-imidazole lactic acid, and imidazole acrylic acid in doses of from one to 5 mg. have no effect on gastric secretion or blood pressure.