Human chorionic gonadotrophin is an endothelium-independent inhibitor of rat aortic smooth muscle contractility

Citation
M. Ezimokhai et al., Human chorionic gonadotrophin is an endothelium-independent inhibitor of rat aortic smooth muscle contractility, AM J HYPERT, 13(1), 2000, pp. 66-73
Citations number
22
Categorie Soggetti
Cardiovascular & Respiratory Systems
Journal title
AMERICAN JOURNAL OF HYPERTENSION
ISSN journal
08957061 → ACNP
Volume
13
Issue
1
Year of publication
2000
Part
1
Pages
66 - 73
Database
ISI
SICI code
0895-7061(200001)13:1<66:HCGIAE>2.0.ZU;2-A
Abstract
The study tested the hypothesis that human chorionic gonadotrophin (hCG) at tenuates isolated vascular smooth muscle contractility and investigated the role of the vascular endothelium in hCG-induced altered responses of vascu lar smooth muscle. The contractile responses of isolated aortic rings from normal, hCG-treated, and estrogen-treated female virgin Wistar rats to phen ylephrine, angiotensin II, KCl, and CaCl2 were compared. The effect of pret reatment with N-monomethyl-L-arginine (L-NMMA), methylene blue, indomethaci n, calcium-free medium, and deendothelialization on responses to phenylephr ine of aortic rings from control and hCG-treated rats were also examined. I ntraperitoneal administration of hCG caused attenuation of contractile resp onses of isolated aortic rings to all agents. The attenuated responses to p henylephrine were not reversed by de-endothelialization, or pretreatment of the rings with L-NMMA, methylene blue, or indomethacin. It was concluded t hat hCG attenuates vascular smooth muscle contractility. The effect is inde pendent of the vascular endothelium, not agonist-specific, and appears to i nvolve alterations of calcium availability. (C) 2000 American Journal of Hy pertension, Ltd.