Pressor response mediated via histamine H1-receptors of the guinea-pig sympathetic ganglia.
In pithed guinea-pigs, the general characteristics and origin of the pressor response to intravenous injection of histamine were examined. Histamine (5-80 micrograms/kg) produced a rapid, short-lasting, constant, prominent and dose-dependent pressor response, followed by a secondary slight and prolonged depressor response. The vascular response to histamine was accompanied by a marked tachycardia. The pressor effect of histamine (30 micrograms/kg) was strongly reduced or abolished in animals pretreated with nicotine, reserpine, bretylium or 6-hydroxydopamine. Furthermore, pyrilamine, a histamine H1-receptor antagonist, antagonized in a dose-dependent manner the pressor response to histamine. On the contrary, metiamide, a histamine H2-receptor antagonist, as well as hexamethonium and atropine, cholinergic antagonists, did not suppress the pressor effect of histamine. The present experiments provide evidence that in guinea-pigs, the pressor component of the vascular response to histamine results predominantly from the activation of histamine H1-receptors in the sympathetic ganglia with consequent release of noradrenaline at postganglionic sympathetic nerve terminals.
Krstić
M K
MK
Department of Pharmacology, Faculty of Medicine, Belgrade, Yugoslavia.
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects*; D001950:Bretylium Tosylate / Q000494:pharmacology; D004246:Dimethylphenylpiperazinium Iodide / Q000494:pharmacology; D005260:Female; D005728:Ganglia, Sympathetic / Q000502:physiology*; D006168:Guinea Pigs; D018738:Hexamethonium; D006584:Hexamethonium Compounds / Q000494:pharmacology; D006632:Histamine / Q000494:pharmacology*; D006892:Hydroxydopamines / Q000494:pharmacology; D008297:Male; D008785:Metiamide / Q000494:pharmacology; D009538:Nicotine / Q000494:pharmacology; D016627:Oxidopamine; D011738:Pyrilamine / Q000494:pharmacology; D011969:Receptors, Histamine H1 / Q000502:physiology*; D012110:Reserpine / Q000494:pharmacology
D006584:Hexamethonium Compounds; D006892:Hydroxydopamines; D011969:Receptors, Histamine H1; D018738:Hexamethonium; D008785:Metiamide; D004246:Dimethylphenylpiperazinium Iodide; D009538:Nicotine; D001950:Bretylium Tosylate; D001285:Atropine; D006632:Histamine; D012110:Reserpine; D016627:Oxidopamine; D011738:Pyrilamine