Abstract
1 The new H2-receptor antagonist, ranitidine, has been compared with cimetidine as an inhibitor of gastric acid secretion in the anaesthetized dog. 2 Both ranitidine and cimetidine given intravenously inhibited histamine-induced gastric secretion in a dose-related manner. Ranitidine was 4.2 times more potent than cimetidine when given as an intravenous infusion and 9.6 times more potent as an intravenous bolus dose. 3 In a separate series of experiments, ranitidine was compared with cimetidine as an antagonist of vasodepressor responses to histamine. Mepyramine alone displaced the histamine dose-response curve to the right. After a maximally effective dose of mepyramine, further displacement could be achieved with ranitidine and cimetidine, ranitidine being 19.2 times more potent than cimetidine. 4 Ranitidine alone has no effect on vasodepressor response curves to histamine, acetylcholine or (-)-isoprenaline or on vasopressor response curves to phenylephrine. 5 These results indicate that displacement of the histamine dose-response curve after mepyramine blockade by ranitidine and cimetidine is due to selective H2-receptor antagonism.
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Selected References
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- BLACK J. W., FISHER E. W., SMITH A. N. Factors affecting histamine-stimulated gastric secretion in anaesthetized dogs. J Physiol. 1958 Apr 3;141(1):22–26. doi: 10.1113/jphysiol.1958.sp005951. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Black J. W., Owen D. A., Parsons M. E. An analysis of the depressor responses to histamine in the cat and dog: involvement of both H1- and H2-receptors. Br J Pharmacol. 1975 Jul;54(3):319–324. doi: 10.1111/j.1476-5381.1975.tb07571.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chand N., Eyre P., DeRoth L. Relaxant action of histamine on rabbit trachea: possible existence of third histamine receptor subtype. Res Commun Chem Pathol Pharmacol. 1979 Feb;23(2):211–221. [PubMed] [Google Scholar]
- Curwain B. P., Holton P. The measurement of dog gastric mucosal blood flow by radioactive aniline clearance compared with amidopyrine clearance. J Physiol. 1973 Feb;229(1):115–131. doi: 10.1113/jphysiol.1973.sp010130. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dale H. H., Laidlaw P. P. Further observations on the action of beta-iminazolylethylamine. J Physiol. 1911 Oct 20;43(2):182–195. doi: 10.1113/jphysiol.1911.sp001464. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dale H. H., Laidlaw P. P. The physiological action of beta-iminazolylethylamine. J Physiol. 1910 Dec 31;41(5):318–344. doi: 10.1113/jphysiol.1910.sp001406. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Daly M. J., Humphray J. M., Stables R. Antagonism of vasodepressor and gastric secretory responses to histamine by ranitidine and cimetidine in the anaesthetised dog [proceedings]. Br J Pharmacol. 1979 Nov;67(3):414P–414P. [PMC free article] [PubMed] [Google Scholar]
- Daly M. J., Humphray J. M., Stables R. Inhibition of gastric acid secretion in the dog by the H2-receptor antagonists, ranitidine, cimetidine, and metiamide. Gut. 1980 May;21(5):408–412. doi: 10.1136/gut.21.5.408. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Powell J. R., Brody M. J. Identification and specific blockade of two receptors for histamine in the cardiovascular system. J Pharmacol Exp Ther. 1976 Jan;196(1):1–14. [PubMed] [Google Scholar]