Objective：To investigate the protective effect of S-adenosylmethionine on liver injury secondary to severe acute pancreatitis (SAP) in rats and its mechanisms.
Methods：Forty-eight rats were equally randomized into sham-operated group, SAP model group and SAP model with two doses (100 mg/kg, 200 mg/kg) of SAM pretreatment groups. Eighteen hours after the models were established, the blood samples of each group were collected to meassure the serum levels of amylase (AMY), alanine transaminase (ALT) and aspartate aminotransferase (AST), and the liver tissues were also harvested to detect the TNF-α expression level by RT-PCR and Western blot methods, respectively.
Results：Comparison to the sham-operated group, the TNF-α mRNA expression in the liver as well as the serum levels of AMY, ALT and AST of other 3 groups all significantly increased to different extents (all P＜0.05). SAM pretreatment of both doses significantly inhibited the elevation of TNF-α expression in the livers, and decreased the serum levels of AMY, ALT and AST, comparing with the SAP rats (both P＜0.05). Moreover, these effects presented in a dose dependent manner (P＜0.05).
Conclusions：Supplemental exogenous SAM  has protective effect on liver injury secondary to SAP, and the mechanism may probably be related to its inhibitory effect on TNF-α expression in the liver.