ALTERATIONS OF METABOLISM IN ISCHEMIC MYOCARDIUM

这些建议的目的是建立代谢的限制， 缺血心肌的适应，并评估设计的几种干预措施 以改善能量产生和/或机械功能。 我们观察到 以前认为，心肌缺血的损害不仅是由于 在氧气输送中，也来自于几种抑制性 代谢物。 然而，修改或规避 这些产物可被影响以刺激残留的氧化磷酸化。 计划在工作猪心中继续进行这些研究。 重点将特别针对确定底物的影响， 增强，记录旨在减弱影响的代理的影响 脂肪酸过量，并进一步详细说明冠状动脉洗脱的影响。 可具有特定优点的替代基材， 乙酰辅酶A含量增加的线粒体，并将在 即将到来的赠款年度包括：乙酸，β-羟基丁酸和丙酮酸， 二氯乙酸盐。 用于调节脂肪酸过量的特定试剂 将是肉毒碱的各种异构体（L，D和DL）。 实验将 形成评估和确定的规模和分布的 胞内掺入的肉毒碱，其异构体的影响， 立体特异性，以及它们对修饰的潜在影响， 改善缺血组织中的能量产生。 评估影响的研究 冠状动脉冲洗对保持代谢和机械功能的影响也是 计划好了 研究将确定缺血中的洗脱是否会改变血管 再分布和氧含量。 人们希望， 通过这几种干预措施， 为未来可能的治疗选择提供见解， 心肌

The objects of these proposals are to establish the limits of metabolic adaptation in ischemic myocardium and to evaluate several interventions designed to improve energy production and/or mechanical function. We have observed previously that the damages of myocardial ischemia result not only from the loss in oxygen delivery, but also from an accumulation of several inhibitory metabolites. Nevertheless, manipulations which either modify or circumvent these products can be affected to stimulate residual oxidative phosphorylation. Studies in working swine hearts are planned to continue these investigations. Emphasis will be specifically directed at determining the effects of substrate enhancement, documenting the influence of agents designed to blunt the effects of fatty acid excess, and further detailing the impact of coronary washout. Alternate substrates which may have specific advantages in providing mitochondria with increased amount of acetyl-CoA and which will be evaluated in the coming grant year include: acetate, beta-hydroxybutyrate and pyruvate with dichloro acetate. Specific agents to be used in modifying fatty acid excess will be the various isomers (L, D and DL) of carnitine. Experiments will be formed to evaluate and determine the magnitude and distribution of the intracellular incorporation of carnitine, the effects of their isomeric stereospecificity, and their potential impact on modifying and hopefully improving energy production in ischemic tissue. Studies to evaluate the impact of coronary washout on preserving metabolic and mechanical functions are also planned. Studies will determine whether washout in ischemia alters vascular redistribution and oxygen content. It is hoped that a critical evaluation of cardiac metabolism and energy production with these several interventions will provide insights to possible future therapeutic options for protecting ischemic myocardium.