NATURE OF HISTAMINE RECEPTORS IN THE EMETIC CHEMORECEPTOR TRIGGER ZONE

Open Access
Publisher Website
Google Scholar
Abstract
The protective effects of the intracerebroventricular (i.c.v.) administration of the H1‐receptor antagonist, mepyramine and the H2‐receptor antagonists, burimamide and metiamide on centrally induced histamine‐emesis were studied in unanaesthetized dogs. The PD50 values of intraventricular mepyramine, burimamide and metiamide against the 100% emetic dose of histamine (3.0 mg i.c.v.) were found to be approximately 200 μg, 20 μg and 20 μg respectively. Although burimamide (i.c.v. or i.v.) afforded protection against histamine‐induced emesis, there was no protection against intravenous apomorphine‐or oral copper sulphate‐induced emesis. The results suggest that both H1‐ and H2‐histamine receptors in the emetic chemoreceptor trigger zone of the area postrema are concerned in histamine‐induced emesis.