组胺通过犬离体门静脉中的H1和H2受体介导的反应。

Histamine responses mediated via H1- and H2-receptors in the isolated portal vein of the dog.

作者信息

Toshimitsu Y, Uchida K, Kojima S, Shimo Y

出版信息

J Pharm Pharmacol. 1984 Jun;36(6):404-5. doi: 10.1111/j.2042-7158.1984.tb04409.x.

DOI:10.1111/j.2042-7158.1984.tb04409.x

Abstract

The effects of histamine were studied on the isolated circular muscle strip and longitudinal muscle strip of the dog portal vein. Histamine-induced contractions of the circular muscle were inhibited by H1-receptor antagonist pyrilamine but increased by H2-receptor antagonist ranitidine. When the tissues were contracted with PGF2 alpha in the presence of pyrilamine, histamine produced the relaxation of the circular muscle but not longitudinal muscle. The relaxation of the circular muscle was inhibited by ranitidine in a concentration dependent manner, the pA2 value for ranitidine being 6.97 (6.55-7.39). It is concluded that the response of the circular muscle to histamine is the sum of two components, H1-receptor mediated contraction and H2-receptor mediated relaxation.

摘要

研究了组胺对犬门静脉分离的环行肌条和纵行肌条的作用。组胺诱导的环行肌收缩被H1受体拮抗剂吡苄明抑制，但被H2受体拮抗剂雷尼替丁增强。当组织在吡苄明存在下用前列腺素F2α收缩时，组胺使环行肌松弛，但对纵行肌无此作用。雷尼替丁以浓度依赖方式抑制环行肌的松弛，雷尼替丁的pA2值为6.97（6.55 - 7.39）。结论是，环行肌对组胺的反应是两个成分的总和，即H1受体介导的收缩和H2受体介导的松弛。