Taurocholic Acid 부하에 의한 쥐 담즙울체간에서 5'-nucleotidase의 유도

Abstract

Possible mechanisms of increase of 5' -nucleotidase (5'-NT) activity in cholestatic rat liver and serum were studied. The hepatic subcellular and serum 5'-NT activities in experimental rats with choledocho-caval shunt (CCS) or bile duct obstruction (BDO) were determined. The Michaelis-Menten constants of these hepatic enzymes were measured. The activities of serum and hepatic cytosolic and microsomal 5'-NT as well as Vmax values of 5" -NT were found to be significantly increased in both CCS plus taurocholic acid (TCA) injected group and BDO plus TCA injected group, compared with the CCS and BDO groups, respectively. However, Km values of the above hepatic 5' -NT did not change in any experimental group. The above results suggest that TCA stimulates biosynthesis of 5'- NT in the liver and the elevated 5' -NT activity in the serum is most likely due to an increase in membrane permeability of hepatocytes upon TCA mediated liver cell necrosis.