Lysosomal enzyme activity in the bile and blood serum was compared in mice with experimental intrahepatic cholestasis induced by alpha-naphthyl isothiocyanate and Triton WR 1339. Triton WR 1339 increases the synthesis of cholesterol (fatty acid precursor) in liver cells. The development of intrahepatic cholestasis was confirmed by the increase in activities of alkaline phosphatase and gamma-glutamyltransferase in blood serum. Administration of Triton WR 1339 in a dose of 100 mg/100 g was followed by a 10-fold increase in beta-galactosidase activity (hepatocyte lysosomal enzyme) in the bile, but not in the serum of mice. beta-Galactosidase activity significantly increased in the bile, but decreased in the serum of mice after treatment with a-naphthyl isothiocyanate in a dose of 200 mg/kg. Our results indicate that intrahepatic cholestasis is manifested in increased secretion of lysosomal glycosidases into the bile. Bile components can aggravate damage to liver cells by affecting the processes of hepatocyte apoptosis and necrosis.