CONTROL OF ENERGY METABOLISM IN CHRONIC ALCOHOLISM

长期饮酒导致线粒体功能障碍 与形态学变化和电子 包括肝脏在内的多种组织中的转运和ATP合酶活性 和心 这些缺陷对生理的影响 慢性酒精中毒动物的肝脏和心脏功能较差 明白 了解变化的后果， 慢性乙醇摄入相关氧化磷酸化 需要采取综合和定量的方法来控制 组织中的能量代谢。 代谢控制分析（MCA） 一种敏感性分析，它提供了一个框架词来描述 复杂代谢网络中的控制分配。 已经 广泛应用于生物能量的定量分析， 系统，无论是在分离的线粒体和完整的细胞和组织。 本提案旨在使用MCA来描述 线粒体氧化磷酸化调控 慢性乙醇消耗后心脏和肝脏的线粒体 使用自上而下的方法，最近开发的分析工具， 使识别的控制所施加的部分， 氧化磷酸化机制（或其他复杂的酶促 路径）。 具体目标是：（1）自上而下识别 氧化磷酸化功能单元的弹性分析 受到完整线粒体中慢性乙醇消耗的影响 从心脏和肝脏;（2）量化乙醇诱导的变化， 心脏和肝脏线粒体在不同条件下的控制模式 基质供应和能量利用条件。 我们将使用 自上而下的弹性分析的结果，结合双 抑制剂滴定和用选择的特异性抑制剂滴定 氧化磷酸化系统的步骤。 我们还将确定 系统中控制分配的变化如何与变化相关 早期报道的酶活性和线粒体的变化 膜性能 这项研究的结果预计将提供 慢性乙醇暴露对细胞的影响 对可能影响生物体的生理压力的反应 易患酒精相关疾病。

Long term alcohol consumption causes mitochondrial dysfunction associated with morphological changes and alterations in electron transport and ATP synthase activity in multiple tissues, including liver and heart. The implications of these deficiencies for the physiological function of liver and heart in chronically alcoholic animals are poorly understood. An understanding of the consequences of the changes in oxidative phosphorylation associated with chronic ethanol intake requires an integrated and quantitative approach to the control of energy metabolism in the tissue. Metabolic Control Analysis (MCA) is a type of sensitivity analysis, which provides a frameword to describe the distribution of control in complex metabolic networks. It has been applied extensively to the quantitative analysis of bioenergetic systems, both in isolated mitochondria and intact cells and tissues. The present proposal is designed to use MCA to characterize changes in the control of mitochondria oxidative phosphorylation in isolated mitochondria from heart and liver after chronic ethanol consumption using the top-down approach, a recently developed analytical tool that enables the identification of the control exerted by segments of the oxidative phosphorylation machinery (or other complex enzymatic pathways). The Specific Aims are: (1) to identify by top-down elasticity analysis the functional units of oxidative phosphorylation that are affected by chronic ethanol consumption in intact mitochondria from heart and liver; (2) to quantify the ethanol-induced changes in the control patterns of heart and liver mitochondria under different conditions of substrate supply and energy utilization. We will use the results of the top-down elasticity analysis, in combination with double inhibitor titrations and titrations with specific inhibitors of select steps of the oxidative phosphorylation system. We will also determine how changes in the control distribution in the system relate to changes in enzymatic activities reported earlier and to changes in mitochondrial membrane properties. The results of this study are expected to provide insights into the effect of chronic ethanol exposure on cellular responses to physiological stress that may affect the organisms susceptibility to the development alcohol-related disorders.