过氧亚硝酸盐
超氧化物
化学
黄嘌呤氧化酶
过氧化氢
血管舒张
黄嘌呤
一氧化氮
钾通道
药理学
生物化学
内分泌学
酶
医学
有机化学
作者
Enoch P. Wei,Hermes A. Kontos,Joseph S. Beckman
出处
期刊:American Journal of Physiology-heart and Circulatory Physiology
[American Physiological Society]
日期:1996-09-01
卷期号:271 (3): H1262-H1266
被引量:117
标识
DOI:10.1152/ajpheart.1996.271.3.h1262
摘要
We investigated the role of potassium channels in the vasodilator action of hydrogen peroxide, peroxynitrite, and superoxide on cerebral arterioles. We studied the effect of topical application of these agents in anesthetized cats equipped with cranial windows. Hydrogen peroxide and peroxynitrite induced dose-dependent dilation that was inhibited by glyburide, an inhibitor of ATP-sensitive potassium channels. Superoxide, generated by xanthine oxidase acting on xanthine in the presence of catalase, also induced dose-dependent dilation of cerebral arterioles that was unaffected by glyburide but inhibited completely by tetraethylammonium chloride, an inhibitor of calcium-activated potassium channels. The vasodilations from hydrogen peroxide, peroxynitrite, or superoxide were unaffected by inhibition of soluble guanylate cyclase with LY-83583. The findings provide pharmacological evidence that hydrogen peroxide and peroxynitrite reversibly dilate cerebral arterioles by activating ATP-sensitive potassium channels, probably through an oxidant mechanism, whereas superoxide dilates cerebral arterioles by opening calcium-activated potassium channels. Activation of soluble guanylate cyclase is not a mediator of the vasodilator action of these agents in cerebral arterioles.
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