Effects of cromakalim on rats vascular smooth muscle with different age
- VernacularTitle:克罗卡林对不同年龄大鼠血管平滑肌张力作用的影响
- Author:
Qi CHEN
;
Xiaoliang WANG
- Publication Type:Journal Article
- From:
Chinese Pharmacological Bulletin
2001;17(2):171-174
- CountryChina
- Language:Chinese
-
Abstract:
AIM To study the effects and mechanisms of cromakal im, an ATP-sensitive K+(KATP) channel opener, on rat vascular smooth mu scl e. METHODS Isometric tension recording of aorta rings. RESULT S Vasorelaxant effects to cromakalim which contracted by phenylephrine we re markedly reduced in the old rats. Endothelium removal or treatment either wit h the NO synthesis inhibitor L-NAME or the guanylate cyclase inhibitor meth ylene blue reduced the effects, however with the change of age, the IC50 v alues and maximal relaxation responses to cromakalim had little difference. Ach and SNP, which are the endogenous and exogenous donors of NO respectively, induc ed a lesser vasodilator effect in aortic segments from old compared with the oth er groups of rats. CONCLUSIONS The vasodilator responses to cromaka lim decreased in old rats, its mechanism may be involved the lower release of NO or the lower sensitivity of vascular smooth muscle to NO.
