Histamine receptors in the vasculature of the rabbit ear.
Histamine has a dual action on the isolated perfused ear preparation of the rabbit. The amine induced a dose-dependent rise in perfusion pressure when the preparation was perfused with Krebs' solution. This pressor response was reversed to a depressor effect when meypramine was added to the perfusion fluid. This depressor effect of the amine was also dose-related. Metiamide competitively inhibited the depressor effect of histamine. Prior treatment of the ear vessels with metiamide alone caused an increase in histamine-induced perfusion pressure. From these results it was concluded that the predominant pressor effect of histamine on the vascular bed of the rabbit ear is mediated through the H1-receptors and the depressor effect of the amine through histamine H2-receptors.
D000109:Acetylcholine / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001158:Arteries / Q000187:drug effects; D004423:Ear / Q000098:blood supply*; D006632:Histamine / Q000494:pharmacology*; D006634:Histamine H1 Antagonists / Q000494:pharmacology; D066298:In Vitro Techniques; D008785:Metiamide / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009638:Norepinephrine / Q000494:pharmacology; D011738:Pyrilamine / Q000494:pharmacology; D011817:Rabbits; D011955:Receptors, Drug; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D014666:Vasomotor System / Q000187:drug effects*
D006634:Histamine H1 Antagonists; D011955:Receptors, Drug; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D000804:Angiotensin II; D008785:Metiamide; D006632:Histamine; D011738:Pyrilamine; D000109:Acetylcholine; D009638:Norepinephrine