Cardiac KATP Channels in Anesthetic-Induced Preconditioning

本项目的总体目标是表征麻醉诱导的预处理（APC）对心肌细胞中肌膜和线粒体ATP敏感性钾（K（ATP））通道、掺入脂质双层的线粒体K（ATP）通道和哺乳动物HEK 293细胞系中表达的重组K（ATP）通道的影响。我们实验室的结果表明，K（ATP）通道是挥发性麻醉剂对缺血和再灌注损伤的心脏保护作用的关键因素。虽然一些研究表明异氟烷和其他挥发性麻醉剂可以模拟缺血预处理，并且这种作用对K（ATP）通道阻滞剂敏感，但没有直接证据表明挥发性麻醉剂与K（ATP）通道之间存在相互作用。这种相互作用在临床上很重要，因为挥发性麻醉剂可以增强或模拟K（ATP）通道开放的保护机制。本计划提出的三个项目中的每一个都将描述腺苷、蛋白激酶C、蛋白酪氨酸激酶和有丝分裂原活化蛋白激酶介导的途径与活性氧相互作用的基本机制， 通过挥发性麻醉剂参与心脏保护。这项工作的总体假设是，挥发性麻醉剂在缺血和再灌注期间通过调节肌膜和线粒体K（ATP）通道的活性来保护心脏。为了实现这一总的假设，我们将讨论以下具体目标： 目的：建立挥发性麻醉药调节大鼠心肌细胞膜K（ATP）通道活性及HEK 293细胞表达重组K（ATP）通道的细胞通路。 目的II-描述挥发性麻醉剂如何改变大鼠心肌细胞和脂质双层中线粒体K（ATP）通道对调节剂的敏感性。 目的III-确定肌膜和线粒体K（ATP）通道对通道的敏感性 体内APC后的调节剂（从项目I获得的心脏）。 总之，项目II将通过研究挥发性有机污染物的直接影响， 在不存在和存在K（ATP）通道调节剂的情况下，麻醉剂对K（ATP）通道的作用。本项目的长期目标将是转化研究，其中我们关于挥发性麻醉剂的心脏保护作用的研究结果可应用于人体研究。

The overall goal of this project is to characterize the effects of anesthetic-induced preconditioning (APC) on sarcolemmal and mitochondrial ATP-sensitive potassium (K(ATP) channels in cardiac myocytes, mitochondrial K(ATP) channels incorporated into lipid bilayers and recombinant K(ATP) channels expressed in the mammalian HEK293 cell line. Results from our laboratory suggest that K(ATP) channels are critical elements in cardioprotection produced by volatile anesthetics against ischemia and reperfusion injury. Although some studies have indicated that isoflurane and other volatile anesthetics can mimic ischemic preconditioning and this action is sensitive to K(ATP) channel blockers, there is no direct evidence of the interaction between volatile anesthetics and the K(ATP) channel. Such an interaction is clinically important because volatile anesthetics may enhance or mimic the protective mechanisms of K(ATP) channel opening. Each of the three projects proposed in this Program will characterize fundamental mechanisms by which adenosine, protein kinase C, protein tyrosine kinase and mitogen-activated protein kinase-mediated pathways and reactive oxygen species interact and participate in cardioprotection by volatile anesthetics. The overall hypothesis of this work is that volatile anesthetics are cardioprotective during ischemia and reperfusion by modulating the activity of sarcolemmal and mitochondrial K(ATP) channels. To pursue this general hypothesis we will address the following specific aims: Aim I- To establish the cellular pathways by which volatile anesthetics modulate sarcolemmal K(ATP) channel activity in rat myocytes and recombinant K(ATP) channel expressed in the HEK293 mammalian cell line. Aim II- To characterize how volatile anesthetics alter the sensitivity of the mitochondrial K(ATP) channel to modulators in rat myocytes and lipid bilayers. Aim III- To determine the sensitivity of sarcolemmal and mitochondrial K(ATP) channels to channel modulators after APC in vivo (hearts obtained from Project I). In summary, Prqiect II will complement Projects I and III by examining the direct effects of volatile anesthetics on K(ATP) channels in the absence and presence of K(ATP) channel modulators. The long-term goal of this Project will be directed to translational research in which our findings concerning the cardioprotective role of volatile anesthetics can be applied to human investigation.