Hood J S, McMahon T J, Kadowitz P J
Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA 70112.
Eur J Pharmacol. 1991 Sep 4;202(1):101-4. doi: 10.1016/0014-2999(91)90260-w.
Pulmonary vascular responses to the K+ATP channel opener, lemakalim, were investigated in the intact-chest cat under constant flow conditions. When tone in the pulmonary vascular bed was elevated, intralobar injections of lemakalim caused dose-related decreases in lobar arterial pressure without changing left atrial pressure. Lemakalim was approximately 3-fold more potent than cromakalim in dilating the pulmonary vascular bed, and pulmonary vasodilator responses to these K+ATP channel openers were blocked by the K+ATP channel blocking agent, glybenclamide. Glybenclamide had no significant effect on pulmonary vasodilator responses to acetylcholine or vasoactive intestinal peptide (VIP) but decreased responses to calcitonin gene-related peptide (CGRP). These data show that lemakalim has potent pulmonary vasodilator activity and suggest that responses are due to activation of a glybenclamide-sensitive K+ATP channel.
在恒流条件下，对开胸猫的肺血管对钾离子通道开放剂雷马卡林的反应进行了研究。当肺血管床张力升高时，叶内注射雷马卡林可导致叶动脉压呈剂量相关下降，而左心房压不变。雷马卡林在扩张肺血管床方面的效力约为克罗卡林的3倍，并且这些钾离子通道开放剂引起的肺血管舒张反应可被钾离子通道阻断剂格列本脲阻断。格列本脲对肺血管对乙酰胆碱或血管活性肠肽（VIP）的舒张反应无显著影响，但可降低对降钙素基因相关肽（CGRP）的反应。这些数据表明雷马卡林具有强大的肺血管舒张活性，并提示该反应是由于格列本脲敏感的钾离子通道被激活所致。
