CONTROL OF ENERGY METABOLISM IN CHRONIC ALCOHOLISM

长期饮酒会导致线粒体功能障碍 与形态变化和电子变化有关 包括肝脏在内的多种组织的转运和ATP合酶活性 还有心。这些缺陷对生理学的影响 慢性酒精中毒动物的肝脏和心脏功能不佳 明白了。对这些变化的后果的理解 慢性酒精摄入与氧化磷酸化相关 需要综合和量化的方法来控制 组织中的能量代谢。代谢控制分析(MCA)是 一种敏感度分析，它提供了一个框架来描述 控制在复杂代谢网络中的分布。一直以来 广泛应用于生物能量的定量分析 系统，包括在分离的线粒体和完整的细胞和组织中。 本提案旨在使用MCA来描述 线粒体氧化磷酸化的调控 慢性饮酒后心脏和肝脏线粒体的变化 使用自上而下的方法，最近开发的分析工具 使得能够识别由 氧化磷酸化装置(或其他复杂的酶 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 在完整的线粒体中受到慢性乙醇消耗的影响 从心脏和肝脏；(2)量化乙醇诱导的 不同条件下心脏和肝脏线粒体的调控模式 底物供应和能源利用的条件。我们将使用 自上而下弹性分析的结果，结合双 抑制剂滴定和与SELECT特定抑制剂的滴定 氧化磷酸化系统的步骤。我们还将确定 系统中控制分配的更改如何与更改相关联 早先报道的酶活性和线粒体的变化 膜特性。这项研究的结果有望为 慢性酒精暴露对细胞影响的研究进展 对可能影响生物体的生理应激的反应 易患上与酒精相关的疾病。

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.