α-D-Mannosidase and β-D-mannosidase activities in cholestatic rat liver induced by bile duct ligation

Abstract

Activities of α-D-mannosidases and β-D-mannosidase under cholestasis were measured. And activities of their serum isozyme activities were also measured. Golgi α-D-mannosidase, microsomal α-D-mannosidase, and lysosomal β-D-mannosidase activities in the cholestatic liver increased after common bile duct(CBD) ligation. Cytosolic α-D-mannosidase, and lysosomal α-D-mannosidase activities in the cholestatic liver decreased after CBD ligation. α-D-Mannosidases and β-D-mannosidase activities in the serum increased after CBD ligation. It is suggested that the increase of glycoproteins under the cholestasis are caused by increased activities of Golgi, and microsomal α-D-mannosidases. α-D-mannosidase and β-D-mannosidase in the liver flow into the blood in large quantities becase of the increased permeability of the cell membrane caused by the cholestasis. And it is suggested that the increase in lysosomal β-D-mannosidase activity in due to increased secondary lysosomes for scavenge of necrotic cells.