Open AccessAge-Associated Endothelial Dysfunction in Rat Mesenteric Arteries: Roles of Calcium-Activated K+ Channels (Kca)
Author(s) -
Enbo Zhou,
Duxin Qing,
J Li
Publication year - 2010
Publication title -
physiological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.647
H-Index - 70
eISSN - 1802-9973
pISSN - 0862-8408
DOI - 10.33549/physiolres.931761
Subject(s) - mesenteric arteries , vasodilation , endothelial dysfunction , medicine , endocrinology , nitric oxide , endothelium , electrical impedance myography , acetylcholine , cardiology , artery
Age-associated changes in large blood vessels were characterizedby increased arterial wall thickness, luminal dilation and impairedendothelial function. But little is known about the effect of age onstructural and functional changes in small resistance arteries. Themechanisms underlying age-associated endothelial dysfunction inrat mesenteric resistance arteries were investigated in thepresent study. Small rat mesenteric arteries were excised andcannulated, and vascular endothelial functions were tested byacetylcholine (ACh). Our experiments showed (1) endotheliumdependent vasorelaxation induced by ACh was reduced in agedmesenteric arteries; (2) blockade of Kca channels markedlyreduced the vasodilation in young and adult rats, the resultantreduction in aged rats was much smaller compared with youngand adult rats; (3) inhibition of endothelial nitric oxide synthase(NOS) resulted in a significant reduction of vasodilation in youngand adult, but there was a smaller reduction in aged rats. Theresults suggest that (1) endothelial function was impaired inmesenteric arteries of aged rats; (2) both Kca channels and nitricoxide (NO) contribute together to the ACh-induced vasorelaxationin small mesenteric arteries, and (3) both the impairment of Kcachannel function and decreased NO account for the age-relatedendothelial dysfunction.