Cardiac KATP Channels in Anesthetic-Induced Preconditioning

本项目的总体目标是研究麻醉诱导的预适应(APC)对心肌细胞肌膜和线粒体三磷酸腺苷敏感钾(K(ATP)通道、掺入脂双层的线粒体K(ATP)通道以及在哺乳动物HEK293细胞系中表达的重组K(ATP)通道的影响。本实验室的研究结果表明，K(ATP)通道是挥发性麻醉药抗缺血再灌流损伤的心脏保护作用的关键成分。虽然已有研究表明异氟醚和其他挥发性麻醉剂可以模拟缺血预适应，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，因为挥发性麻醉药可以增强或模拟K(ATP)通道开放的保护机制。本计划中提出的三个项目中的每一个都将表征腺苷、蛋白激酶C、蛋白酪氨酸激酶和丝裂原活化蛋白激酶介导的途径和活性氧物种相互作用和相互作用的基本机制 参与挥发性麻醉剂的心脏保护。这项工作的总体假设是，挥发性麻醉剂通过调节肌膜和线粒体K(ATP)通道的活性，在缺血和再灌流期间具有心脏保护作用。为了实现这一一般性假设，我们将解决以下具体目标： 目的：建立挥发性麻醉药调节大鼠心肌细胞肌膜K(ATP)通道活性的细胞通路以及在HEK293细胞中表达的重组K(ATP)通道。 目的II-研究挥发性麻醉药如何改变大鼠心肌细胞和脂质双分子层线粒体K(ATP)通道对调节剂的敏感性。 目的III-测定肌膜和线粒体K(ATP)通道对通道的敏感性 体内APC后的调节器(从项目I获得的心脏)。 总之，方案二将通过审查挥发性物质的直接影响来补充项目一和项目三。 K(ATP)通道调节剂存在和不存在时，麻醉药对K(ATP)通道的影响。该项目的长期目标将指向转化性研究，在这些研究中，我们关于挥发性麻醉剂的心脏保护作用的发现可以应用于人类研究。

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.