Tucker A, Weir EK, Reeves JT, Grover RF. Histamine H1- and H2-receptors in pulmonary and systemic vasculature of the dog.
THE AMERICAN JOURNAL OF PHYSIOLOGY 1975;
229:1008-13. [PMID:
242221 DOI:
10.1152/ajplegacy.1975.229.4.1008]
[Citation(s) in RCA: 80] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This study was conducted to identify and clarify the actions of pulmonary and systemic H1- and H2-receptors by utilizing specific histamine receptor antagonists. Histamine was infused in anesthetized dogs during control conditions, after H2-receptor blockade with metiamide, after H1-receptor blockade with chlorpheniramine, and after combined H1- and H2-receptor blockade. Histamine infusion, alone, induced marked systemic vasodilatation, pulmonary vasoconstriction, and transient increases in cardiac output and heart rate. H2-receptor blockade prevented the systemic vasocilatation and potentiated the pulmonary vasoconstriction induced by histamine. H1-receptor blockade augmented the systemic vasodilatation, prevented the pulmonary vasoconstriction, and increased the cardiac output and heart rate responses induced by histamine. Thus, H2-receptors appear to mediate the vasocilatation, tachycardia, and increased cardiac output induced by histamine, whereas H1-receptors appear to mediate the vasoconstrictor and the minimal cardiac depressent actions of histamine. Histamine stimulates only H1- and H2-receptors, since combined H1- and H2-receptor antagonism prevented almost all of the cardiovascular actions of histamine.
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