[Alcoholism: biology].

This article discusses biochemical changes of ethyl alcohol in human organism, concentrating especially on the negative influence on the metabolism of liver. The authors describe the process of oxidation of alcohol with alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) and emphasize the role of ADH i ALDH isoenzymes in creating individual tolerance of ethanol. Two other ways of ethanol metabolism are also presented. These are: microsomal ethanol oxidation system (MEOS) connected with cytochrome P-450 and peroxisome catalase system. The article also describes the influence of alcohol and its products of metabolism on the structure of liver proteins, on different metabolic processes taking place in this organ, and on the changes in the immunological system in the course of the alcoholic liver disease. Moreover, the authors present some information about the changes in histopathological picture of liver as the result of alcohol abuse.