Longmore J, Newgreen D T, Weston A H
Department of Physiological Sciences, University of Manchester, U.K.
Eur J Pharmacol. 1990 Nov 6;190(1-2):75-84. doi: 10.1016/0014-2999(90)94114-d.
The study investigated the possible involvement of an ATP-sensitive potassium (K) channel in the relaxant actions of K channel openers in rat portal vein. The effects of glibenclamide on the relaxant responses and rises in 86Rb efflux evoked by cromakalim, RP49356 and diazoxide were studied. The effects of galanin and depletion of intracellular ATP concentrations [( ATP]i) were also examined. Galanin increased mechanical activity and 86Rb efflux, effects most likely mediated via galanin receptors rather than a direct action on a K channel. Glibenclamide inhibited the relaxant responses and rises in 86Rb efflux evoked by cromakalim, RP49356 and diazoxide. Reduction of [ATP]i caused relaxation and this effect was partially reversed by glibenclamide. The restored activity was abolished by cromakalim. These results suggest that an ATP-sensitive K channel is present on rat portal vein and that it may be involved in the relaxant actions of cromakalim, RP49356 and diazoxide.
该研究调查了ATP敏感性钾（K）通道在大鼠门静脉中钾通道开放剂舒张作用中的可能参与情况。研究了格列本脲对由克罗卡林、RP49356和二氮嗪引起的舒张反应及86Rb外流增加的影响。还检测了甘丙肽的作用以及细胞内ATP浓度（[ATP]i）的降低情况。甘丙肽增加了机械活性和86Rb外流，其作用很可能是通过甘丙肽受体介导的，而非直接作用于钾通道。格列本脲抑制了由克罗卡林、RP49356和二氮嗪引起的舒张反应及86Rb外流增加。[ATP]i的降低导致舒张，且这种作用被格列本脲部分逆转。恢复的活性被克罗卡林消除。这些结果表明大鼠门静脉存在ATP敏感性钾通道，且它可能参与了克罗卡林、RP49356和二氮嗪的舒张作用。
