S-adenosylmethionine treatment prevents carbon tetrachloride-induced S-adenosylmethionine synthetase inactivation and attenuates liver injury.

Administration of carbon tetrachloride to rats resulted in induction of hepatic fibrosis and a 60% reduction of hepatic S-adenosylmethionine synthetase activity without producing any significant modification of hepatic levels of S-adenosylmethionine synthetase messenger RNA. The reduction of S-adenosylmethionine synthetase activity was corrected by treatment with S-adenosylmethionine (3 mg/kg/day, intramuscularly). Administration of carbon tetrachloride also produced a 45% depletion of liver glutathione (reduced form) that was corrected by S-adenosylmethionine treatment. After the rats received carbon tetrachloride, a 2.3-fold increase in liver collagen was observed; prolyl hydroxylase activity was 2.5 times greater than that seen in controls. These increases were attenuated in animals treated with carbon tetrachloride and S-adenosylmethionine. The attenuation by S-adenosylmethionine treatment of the fibrogenic effect of carbon tetrachloride was associated with a decrease in the number of rats in which cirrhosis developed.