Vasodilation of brain surface arterioles by blockade of Na–H+ antiport and its inhibition by inhibitors of KATP channel openers

摘要: Pial artrioles of rats were monitored in vivo and found to dilate dose-dependent fashion upon application either benzamil or ethyl isopropyl amiloride, both which are inhibitors the sodium-hydrogen antiport. Antiport blockade is known decrease internal pH vascular smooth muscle (VSM). The dilation was blocked by 1 microm glibenclamide, that dose a selective inhibitor ATP sensitive potassium channels (K(ATP)). nitric oxide synthase nitro-l arginine (l-NNA) also response. Previous studies this preparation under same experimental conditions showed l-NNA inhibited K(ATP) openers had no permissive action setting. Moreover, one study others has demonstrated site on surface while another sodium propionate, direct acidifier cell, dilates rat basilar artery K(ATP)-dependent fashion. Therefore, present data support following conclusions: brain arterioles; response dependent; some situations, can inhibit dilations including those produced pH.