Microsomal function in biliary obstructed rats: effects of S-adenosylmethionine

S-adenosylmethionine has been reported to have beneficial effects in the treatment of different chronic liver diseases and to protect against different hepatotoxic agents. The aim of this study was to investigate whether S-adenosylmethionine treatment might contribute to improved microsomal function in chronically biliary obstructed rats. Methods: Secondary biliary cirrhosis was induced by 28 days of bile duct obstruction. Groups of control and Cirrhotic animals received S-adenosylmethionine (10 mg/kg per day) through the experimental period. Results: Bile duct obstruction resulted in a marked incrase in lipid peroxidation levels and decreases in glutathione concentration, microsomal membrane fluidityy, microsomal cytochrome P-450 content, NADPH-cytochrome P-450 reductase activity and the activities of the aniline hydroxylase, aminopyrine demethylase and ethoxycoumrin deethylase. Reductions in glutathione and cytochrome P-450 concentration were not corrected by S-adenosylmethionine, but lipid peroxidation, the decrease in the activities of the various microsomal monooxygenases and the reduction in microsomal membrane fluidity were partially prevented. A significant relationship was found between membrane fluidity and aniline hydroxylase, aminopyrine demethylase or ethoxycoumarin deethylase activities. Conclusions: S-adenosylmethionine administration partially preserves microsomal function. This effect could be associated to the protection of membrane function by restoring transmethylation reactions.