Effects of Extrahepatic Cholestasis on Liver and Serum $\beta$-D-Mannosidase Activities in Ethanol Intoxicated Rats

Liver and serum $\beta$-D-mannosidase activities were determined in ethanol intoxicated rats with extrahepatic cholestasis induced by common bile duct ligation (CBD) to manifest the biochemical background of alcohol drinking hazard under the hepatobiliary disease. Liver $\beta$-D-mannosidase activity and its Vmax value in CBD ligated rats with chronic ethanol intoxication were found to be significantly decreased than that in CBD ligation alone. However, the difference of Km value on above hepatic enzyme was not found between the experimental groups. On the other hand, serum $\beta$-D-mannosidase activity in CBD ligated rats with chronic ethanol intoxication was increased more than that in CBD ligation alone. These results indicate that the biosynthesis of the hepatic $\beta$-D-mannosidase decreases and the serum $\beta$-D-mannosidase activity increases in cholestasis combined with chronic ehtanol intoxication, reflecting damage of aggravated hapatocytic membrane. Accordingly, the resulting data supported the fact that alcoholic drinks were enzymologically harmful to the hepatobiliary disease.