Abstract
1 Ranitidine has been investigated as an antagonist of the H2-receptor-mediated responses to histamine of guniea-pig atrium and rat uterus in vitro and as an inhibitor of gastric acid secretion in the rat. 2 Ranitidine competitively antagonized histamine-induced increases in contraction frequency of the guinea-pig isolated rat atrium. Ranitidine had a pA2 of 7.2 and was 7.9 and 4.5 times more potent than metiamide and cimetidine respectively. 3 Ranitidine competitively antagonized histamine-induced relaxations of the rat isolated uterine horn. Ranitidine had a pA2 of 6.95 and was 3.6 and 5.9 times more potent than metiamide and cimetidine respectively. 4 Ranitidine, even at high concentrations, did not affect responses of the guinea-pig isolated atrium or rat isolated uterus to (-)-isoprenaline. Similarly it was without effect on either histamine or bethanechol-induced contractions of guinea-pig isolated ileum. 5 Ranitidine inhibited histamine- and pentagastrin-induced gastric acid secretion in the perfused stomach preparation of the anaesthetized rat. Ranitidine was 5.2 and 7.0 times more potent on a molar basis than metiamide and cimetidine respectively, as an inhibitor of histamine-induced gastric acid secretion. 6 It is concluded that ranitidine is a potent, competitive and selective antagonist of histamine at H2-receptor sites and and effective inhibitor of gastric acid secretion in vivo.
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- ARUNLAKSHANA O., SCHILD H. O. Some quantitative uses of drug antagonists. Br J Pharmacol Chemother. 1959 Mar;14(1):48–58. doi: 10.1111/j.1476-5381.1959.tb00928.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ash A. S., Schild H. O. Receptors mediating some actions of histamine. Br J Pharmacol Chemother. 1966 Aug;27(2):427–439. doi: 10.1111/j.1476-5381.1966.tb01674.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Black J. W., Duncan W. A., Durant C. J., Ganellin C. R., Parsons E. M. Definition and antagonism of histamine H 2 -receptors. Nature. 1972 Apr 21;236(5347):385–390. doi: 10.1038/236385a0. [DOI] [PubMed] [Google Scholar]
- Black J. W., Duncan W. A., Emmett J. C., Ganellin C. R., Hesselbo T., Parsons M. E., Wyllie J. H. Metiamide--an orally active histamine H2-receptor antagonist. Agents Actions. 1973 Oct;3(3):133–137. doi: 10.1007/BF01965723. [DOI] [PubMed] [Google Scholar]
- Bradshaw J., Brittain R. T., Clitherow J. W., Daly M. J., Jack D., Price B. J., Stables R. Ranitidine (AH 19065): a new potent, selective histamine H2-receptor antagonist [proceedings]. Br J Pharmacol. 1979 Jul;66(3):464P–464P. [PMC free article] [PubMed] [Google Scholar]
- Brimblecombe R. W., Duncan W. A., Owen D. A., Parsons M. E. The pharmacology of burimamide and metiamide, two histamine H2-receptor antagonists. Fed Proc. 1976 Jun;35(8):1931–1934. [PubMed] [Google Scholar]
- Carlson H. E., Ippoliti A. F. Cimetidine, an H2-antihistamine, stimulates prolactin secretion in man. J Clin Endocrinol Metab. 1977 Aug;45(2):367–370. doi: 10.1210/jcem-45-2-367. [DOI] [PubMed] [Google Scholar]
- Forrest J. A., Shearman D. J., Spence R., Celestin L. R. Letter: Neutropenia associated with metiamide. Lancet. 1975 Feb 15;1(7903):392–393. doi: 10.1016/s0140-6736(75)91305-7. [DOI] [PubMed] [Google Scholar]
- Funder J. W., Mercer J. E. Cimetidine, a histamine H2 receptor antagonist, occupies androgen receptors. J Clin Endocrinol Metab. 1979 Feb;48(2):189–191. doi: 10.1210/jcem-48-2-189. [DOI] [PubMed] [Google Scholar]
- GHOSH M. N., SCHILD H. O. Continuous recording of acid gastric secretion in the rat. Br J Pharmacol Chemother. 1958 Mar;13(1):54–61. doi: 10.1111/j.1476-5381.1958.tb00190.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ganellin C. R., Durant G. J., Emmett J. C. Some chemical aspects of histamine H2-receptor antagonists. Fed Proc. 1976 Jun;35(8):1924–1930. [PubMed] [Google Scholar]
- Owen D. A. Histamine receptors in the cardiovascular. Gen Pharmacol. 1977;8(3):141–156. doi: 10.1016/0306-3623(77)90043-x. [DOI] [PubMed] [Google Scholar]
- Peden N. R., Saunders J. H., Wormsley K. G. Inhibition of pentagastrin-stimulated and nocturnal gastric secretion by ranitidine. A new H2-receptor antagonist. Lancet. 1979 Mar 31;1(8118):690–692. doi: 10.1016/s0140-6736(79)91146-2. [DOI] [PubMed] [Google Scholar]