CHRONIC ALCOHOLISM & LIVER ENERGY & LIPID METABOLISM

我工作的长期目标是在生物化学方面 降低慢性乙醇导致的肝脏相关病理学 消费 重点将是调查那些 细胞能量代谢过程中发生的生化变化， 酒精性肝病的早期（脂肪肝）阶段。 项目 本建议中所述的目的是1）确定 ATP合成系统被慢性乙醇消耗改变，2） 提供关于乙醇促进损害的机制的信息， 线粒体，和3）确定这种损害对细胞的影响， 能量代谢 我们实验室迄今的研究表明， 肝脏线粒体中乙醇相关的改变是1）降低 ATP合成酶复合物的活性，2）降低能量守恒， 电子传递链的NADH-泛醌还原酶片段，和 3)细胞器的脆弱性增加， 对于减少ATP合成的总线粒体补体在 脂肪肝 因此，我们选择了这三个病变进行进一步的研究。 调查事务所 乙醇相关的改变 ATP合成酶的多肽-磷脂结构将是 测定 乙醇引起的细胞功能的变化 NADH-泛醌还原酶复合物，以驱动 电化学质子梯度将进一步详细表征。 实验还被设计来确定增加的 乙醇喂养大鼠肝线粒体的脆性。 包括的是 肝线粒体更新的测量。 以上将结合乙醇相关的调查 肝细胞进行的肝脏能量代谢的改变， 原位肝 肝脏能量状态下降的程度 将在原位完整肝脏中研究慢性乙醇消耗 在肝细胞中，利用31 P NMR光谱测定细胞 磷酸化潜力。 乙醇引起的功能改变， 体内的质子将通过测量质子动力学来评估。 由肝细胞内的线粒体产生的力。

The long-term objective of my work is to characterize at the biochemical level the liver-associated pathology which results from chronic ethanol consumption. The major emphasis will be an investigation of those biochemical changes that occur in cellular energy metabolism during the early (fatty liver) stage of ethanol-induced liver disease. The project described in this proposal is designed to 1) determine how much the ATP-synthesizing system is altered by chronic ethanol consumption, 2) provide information on the mechanism by which ethanol elicits damage to mitochondria, and 3) determine the effects of such damage on cellular energy metabolism. Studies in our laboratory ot date indicate that among all the ethanol-related alterations in hepatic mitochondria it is 1) the lowered activity of the ATP synthetase complex, 2) decreased energy conservation in the NADH-ubiquinone reductase segment of the electron transport chain, and 3) increased fragility of the organelle that are most likely responsible for decreased ATP synthesis by the total mitochondrial complement in the fatty liver. We have thus selected these three lesions for further investigations. Ethanol-related alterations in the polypeptide-phospholipid structure of the ATP synthetase will be determined. The ethanol-elicited changes in the ability of the NADH-ubiquionone reductase complex to drive the formation of an electrochemical proton gradient will be characterized in further detail. Experiments are also designed to determine the effects of the increased fragility of hepatic mitochondria from ethanol-fed rats. Included are measurements os hepatic mitochondria turnover. The above will be combined with investigations of ethanol-related alterations in liver energy metabolism carried out with hepatocytes and in situ liver. The degree to which the energy state of the liver is decreased by chronic ethanol consumption will be investigated in intact liver in situ and in hepatocytes, utilizing 31P NMR spectroscopy to determine cellular phosphorylation potential. Ethanol-elicited functional alterations in the mitochondrion in vivo will be assessed by measurements of the protonmotive force generated by mitochondria inside the hepatocyte.