Ultrastructural evaluation of lysosomes and biochemical changes in cathepsin D distribution in hepatocytes in methanol intoxication.

Methanol oxidation is accompanied by free radicals and formaldehyde formation. It is likely to cause damage of lysosomal membranes. Lysosomal ultrastructure under transmission electron microscope and biochemical localization of cathepsin D were estimated after rats intoxication with methanol. The examination was carried out 6, 12 and 24 h and 2.5 and 7 days after intoxication. Ultrastructural examination showed that methanol causes extension of Golgi apparatus cisterns and an increase in a number of lysosomes. From 12 h to 2 days lysosomes were characterized by damage of structure of membrane enclosing lysosomes. During the first days of intoxication activity of cathepsin D decreased in lysosomes and increased in cytosol. These changes may lead to uncontrolled extralysosomal proteolysis in the liver cells and to the onset of liver tissue destruction.