Lin R C, Lumeng L
Department of Medicine, Indiana University School of Medicine, Indianapolis.
Alcohol Alcohol Suppl. 1991;1:265-9.
A liver protein with molecular weight of 37,000 can form adducts with acetaldehyde in vivo when rats are fed alcohol chronically. This 37KD protein is not directly involved in the hepatic metabolism of ethanol but it requires alcohol dehydrogenase activity to form adducts with acetaldehyde. The 37KD protein-AA is located in cytosol of the liver. However, under certain circumstances e.g. when fed an alcohol-containing liquid diet supplemented with cyanamide (an aldehyde dehydrogenase inhibitor that raises blood acetaldehyde concentrations), this 37KD protein-acetaldehyde adduct (protein-AA) becomes incorporated into liver plasma membranes. The same 37KD protein-AA can also form in vitro with cultured rat hepatocytes treated with ethanol. The formation of the 37KD protein-AA in the cultured liver cells increased with time and was dependent on concentrations of ethanol in the culture medium. Thus, protein-AAs can form in vivo and in liver cell culture upon chronic alcohol exposure, and a 37KD protein in liver is highly susceptible to chemical modification by acetaldehyde.
当大鼠长期摄入酒精时，一种分子量为37000的肝脏蛋白可在体内与乙醛形成加合物。这种37KD蛋白不直接参与乙醇的肝脏代谢，但它需要酒精脱氢酶活性才能与乙醛形成加合物。37KD蛋白-乙醛加合物位于肝脏的细胞质中。然而，在某些情况下，例如当给大鼠喂食补充了氨甲环酸（一种可提高血液乙醛浓度的乙醛脱氢酶抑制剂）的含酒精液体饮食时，这种37KD蛋白-乙醛加合物（蛋白-AA）会整合到肝细胞膜中。同样的37KD蛋白-AA也可在体外由经乙醇处理的培养大鼠肝细胞形成。培养的肝细胞中37KD蛋白-AA的形成随时间增加，且依赖于培养基中乙醇的浓度。因此，长期暴露于酒精时，蛋白-AA可在体内和肝细胞培养物中形成，肝脏中的一种37KD蛋白极易受到乙醛的化学修饰。
