title: Nature of histamine receptors in the emetic chemoreceptor trigger zone.
abstract: 1 The protective effects of the intracerebroventicular (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. 2 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 mug, 20 mug and 20 mug respectively. 3 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. 4 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.
mesh_terms: D000818:Animals; D002049:Burimamide / Q000494:pharmacology; D002628:Chemoreceptor Cells / Q000502:physiology*; D004285:Dogs; D004639:Emetics / Q000494:pharmacology*; D005260:Female; D006632:Histamine / Q000008:administration & dosage / Q000494:pharmacology / Q000502:physiology*; D007276:Injections, Intraventricular; D008297:Male; D008785:Metiamide / Q000494:pharmacology; D011738:Pyrilamine / Q000494:pharmacology; D011955:Receptors, Drug / Q000187:drug effects*
chemical_list: D004639:Emetics; D011955:Receptors, Drug; D008785:Metiamide; D006632:Histamine; D011738:Pyrilamine; D002049:Burimamide