|
KMID : 0359920140330040181
|
|
Korean Journal of Nephrology
2014 Volume.33 No. 4 p.181 ~ p.186
|
|
|
Mechanisms of phytoestrogen biochanin A-induced vasorelaxation in renovascular hypertensive rats
|
|
Choi Seok
Jung Won-Suk
Cho Nam-Soo
Ryu Kwon-Ho
Jun Jae-Yeoul
Shin Byung-Chul
Chung Jong-Hoon
Yeum Cheol-Ho
|
|
|
Abstract
|
|
|
Background: The plant-derived estrogen biochanin A is known to cause vasodilation, but its mechanism of action in hypertension remains unclear. This study was undertaken to investigate the effects and mechanisms of biochanin A on the thoracic aorta in two-kidney, one clip (2K1C) renovascular hypertensive rats.
Methods: Hypertension was induced by clipping the left renal artery, and control age-matched rats were sham treated. Thoracic aortae were mounted in tissue baths to measure isometric tension.
Results: Biochanin A caused concentration-dependent relaxation in aortic rings from 2K1C hypertensive and sham-treated rats, which was greater in 2K1C rats than in sham rats. Biochanin A-induced relaxation was significantly attenuated by
removing the endothelium in aortic rings from 2K1C rats, but not in sham rats. Nω-Nitro-L-arginine methyl ester, a nitric oxide synthase inhibitor, or indomethacin, a cyclooxygenase inhibitor, did not affect the biochanin A-induced relaxation in
aortic rings from 2K1C and sham rats. By contrast, treatment with glibenclamide, a selective inhibitor of adenosine triphosphate-sensitive Kþ channels, or tetraethylammonium, an inhibitor of Ca2þ-activated Kþ channels, significantly reduced biochanin A-induced relaxation in aortic rings from both groups. However, 4-aminopyridine, a selective inhibitor of voltage-dependent Kþ channels, inhibited the relaxation induced by biochanin A in 2K1C rats, whereas no significant
differences were observed in sham rats.
Conclusion: These results suggest that the enhanced relaxation caused by biochanin A in aortic rings from hypertensive rats is endothelium dependent. Vascular smooth muscle Kþ channels may be involved in biochanin A-induced relaxation in aortae from hypertensive and normotensive rats. In addition, an endotheliumderived activation of voltage-dependent Kþ channels contributes, at least in part, to the relaxant effect of biochanin A in renovascular hypertension.
|
|
|
KEYWORD
|
|
|
Biochanin A, Endothelium, Kþ channels, Renovascular hypertension
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
  
|
|