Chronic ethanol consumption alters the glutathione/glutathione peroxidase-1 system and protein oxidation status in rat liver
Chronic ethanol consumption alters the glutathione/glutathione peroxidase-1 system and protein oxidation status in rat liver
复制标题
DOI：
10.1111/j.1530-0277.2001.tb02273.x
复制
发表时间：
2001-05-01
影响因子：
3.2
通讯作者：
Cunningham, CC
中科院分区：
文献类型：
--
作者：
Bailey, SM;Patel, VB;Cunningham, CC
背景资料：酒精引起的肝损伤与氧化应激有关，这可能与肝脏抗氧化防御机制的紊乱有关。因此，在大鼠中研究了慢性乙醇消耗对线粒体和细胞溶质谷胱甘肽/谷胱甘肽过氧化物酶-1（GSHPx-1）系统和蛋白质氧化修饰的影响。方法：雄性Sprague-Dawley（（R））大鼠喂食液体饮食，提供36%的总热量作为乙醇至少31天。成对喂养的对照组接受等热量的饮食，用麦芽糖糊精代替乙醇热量。线粒体和胞质组分从肝脏和毛皮谷胱甘肽过氧化物酶-1和谷胱甘肽还原酶活性和总的谷胱甘肽和氧化浓度进行了测定。在线粒体后上清液中测定过氧化氢酶活性。通过蛋白质印迹分析测定GSH Px-1、乳酸脱氢酶和ATP合酶蛋白的F1部分的β亚基的水平。线粒体和胞浆蛋白羰基的浓度进行测量，以评估乙醇诱导的氧化protein.Results：慢性乙醇消耗显着降低细胞溶质和线粒体GSHPx-1的活性分别为40%和30%。GSHPx-1蛋白质在细胞质中的水平不受乙醇喂养，而有一个小的减少，GSHPx-1蛋白质水平从乙醇喂养的大鼠分离的线粒体。乙醇暴露的结果，在细胞内的隔室和过氧化氢酶的活性增加，谷胱甘肽还原酶的活性增加。胞浆总谷胱甘肽轻度减少，而乙醇喂养增加线粒体总谷胱甘肽水平。慢性乙醇喂养显着增加了30%和60%，respectively：本研究表明，慢性乙醇诱导的谷胱甘肽/GSHPx-1抗氧化系统的改变，可能会促进肝蛋白的氧化修饰，即那些的peptide，这可能有助于乙醇对肝脏的不利影响。
Background: Alcohol-induced liver damage is associated with oxidative stress, which might be linked to disturbances in liver antioxidant defense mechanisms. The effect of chronic ethanol consumption on the mitochondrial and cytosolic glutathione/glutathione peroxidase-1 (GSHPx-1) system and oxidative modification of proteins was therefore studied in the rat.Methods: Male Sprague-Dawley((R)) rats were fed liquid diets that provided 36% total calories as ethanol for at least 31 days. Pair-fed controls received isocaloric diets with ethanol calories substituted with maltose-dextrins. Mitochondrial and cytosolic fractions were prepared from livers and assayed fur GSHPx-1 and glutathione reductase activities and total and oxidized concentrations of glutathione. Catalase activity was measured in the postmitochondrial supernatant. Levels of GSHPx-1, lactate: dehydrogenase, and the beta subunit of the F, portion of the ATP synthase protein were determined by western blot analysis. Concentrations of mitochondrial and cytosolic protein carbonyls were measured to assess ethanol-induced oxidation of proteins.Results: Chronic ethanol consumption significantly decreased cytosolic and mitochondrial GSHPx-1 activities by 40% and 30%, respectively. Levels of GSHPx-1 protein in cytosol were unaffected by ethanol feeding, whereas there was a small decrease in GSHPx-1 protein levels in mitochondria isolated from ethanol-fed rats. Glutathione reductase activities were increased in both intracellular compartments and catalase activity was increased as a consequence of ethanol exposure. Cytosolic total glutathione was mildly decreased, whereas ethanol feeding increased mitochondrial levels of total glutathione. Chronic ethanol feeding significantly increased both cytosolic and mitochondrial concentrations of protein carbonyls by 30% and 60%, respectively.Conclusions: This study demonstrates that chronic ethanol-induced alterations in the glutathione/GSHPx-1 antioxidant system might promote oxidative modification of liver proteins, namely those of the mitochondrion, which could contribute to the adverse effects of ethanol on the liver.