ANESTHETICS AND CARDIAC SIGNAL TRANSDUCTION

描述(由申请人提供)： 越来越多的实验和临床证据表明，某些挥发性麻醉剂通过激活内源性保护细胞机制，使心脏免受不可逆的缺血/再灌注损伤。这种现象被称为麻醉性预适应(APC)。在前一个授予周期中，我们从豚鼠心脏获得的数据表明，麻醉剂开放KA/ATP通道有助于APC的发生。由于APC可能因物种不同而不同，因此建立人类心肌APC的致病机制是很重要的。因此，我们的目标是研究在分离的人心房肌细胞中参与APC的信号通路，并确定SARC和mitoK/ATP通道在挥发性麻醉药产生的细胞保护中的各自作用。这将通过使用电生理、生化、分子和免疫组织化学技术来完成。有待检验的主要假设是，在人的心肌中，SARC和mitoKar P通道参与了急性APC提供的细胞保护。为了实现这一假设，我们将解决以下具体目标： 目的：研究急性APC对人心房肌细胞肌酸激酶/三磷酸腺苷(SarCK/ATP)通道的影响。假设：挥发性麻醉药调节人的SarCK/ATP通道及其对核苷酸、蛋白激酶(PKC、PTK、MAPK)和活性氧的敏感性。 目的II：研究APC对完整心肌细胞的mitOK/ATP通道活性、线粒体功能和平面脂双层膜的mitoK/ATP通道的影响。假设：挥发性麻醉剂通过多条信号通路调节线粒体功能和人类mitoKare通道的活性。 目的：研究急性APC对体外培养的人心房肌细胞存活的影响。假设：SARC和mitOK/ATP通道在APC提供的细胞缺血损伤保护中发挥作用，并且这种保护是麻醉专一性的。综上所述，本研究项目将描述KATP通道在人心房肌细胞中的重要性，并评估在体外介导APC的特定信号通路。这一建议代表了对挥发性麻醉剂诱导的抗缺血/再灌注损伤的心脏保护这一重要的和临床相关现象的综合方法。

DESCRIPTION (provided by applicant): A growing body of experimental and clinical evidence indicates that certain volatile anesthetics precondition the heart against irreversible ischemia/reperfusion injury by activating endogenous protective cellular mechanisms. This phenomenon has been termed the anesthetic-induced preconditioning (APC). During the previous grant cycle, we obtained data from guinea pig hearts to suggest that opening of the KA/ATP channel by anesthetics contributes to APC. Because APC may vary among species, it is important to establish the mechanisms responsible for APC in human myocardium. Therefore, the objective of our proposal is to investigate the signaling pathways responsible for APC in isolated human atrial myocytes and determine the respective roles of sarc and mitoK/ATP channels in cytoprotection produced by volatile anesthetics. This will be accomplished by the use of electrophysiological, biochemical, molecular and immunohistochemical techniques. The major hypothesis to be tested is that in human myocardium the sarc and mitoKar P channels are involved in cytoprotection afforded by acute APC. To pursue this hypothesis we will address the following specific aims: Aim I: To identify cellular pathways by which acute APC modulates the sarCK/ATP channel in human atrial myocytes. Hypothesis: Volatile anesthetics modulate the human sarCK/ATP channel and its sensitivity to nucleotides, protein kinases (PKC, PTK, MAPK) and reactive oxygen species. Aim II: To characterize how APC affects activity of mitOK/ATP channels in intact myocytes, mitochondrial function and mitoK/ATP channels in planar lipid bilayers. Hypothesis: Volatile anesthetics regulate mitochondrial function and activity of the human mitoKare channel via multiple signaling pathways. Aim III: To characterize the efficacy of acute APC on survival of isolated human atrial myocytes. Hypothesis: Sarc and mitOK/ATP channels play a role in cellular protection against ischemic injury afforded by APC, and this protection is anesthetic specific. In summary, this research project will characterize the importance of the KATP channel in human atrial myocytes and evaluate specific signaling pathways that mediate APC in vitro. This proposal represents a comprehensive approach to the significant and clinically relevant phenomenon of volatile anesthetic-induced cardioprotection against ischemia/reperfusion injury.