The alterations of vascular smooth muscle reactivity in vitro by human chorionic gonadotrophin.

摘要: The study tests the hypothesis that human chorionic gonadotrophin (hCG) alters vascular smooth muscle reactivity by examining effect of hCG administration on contractility and relaxation isolated muscle. Aortic rings from rats pre-treated with intraperitoneal 5,000 I.U control animals were contracted to phenylephrine, angiotensin II, CaCl2 KCl. experiments phenylephrine repeated either de-endothelialized, incubated L-NMMA, or calcium ionophore A23187. precontracted relaxed acetylcholine (endothelium-dependent), sodium nitroprusside, hydralazine (endothelium-independent) in presence contractile responses aortic hCG-treated KCl significantly attenuated. This was not reversed pre-treatment L-NMMA de-endothelialisation. In animals, there almost total inhibition acetylcholine-induced relaxation, but unaltered nitroprusside hydralazine. inhibitory effects hCG-treatment both contraction fully partially These observations suggest attenuates endothelium-dependent a mechanism which involves extracellular ion influx may indicate new role for hormone altered normal abnormal pregnancies.