Protective Effect Of N-acetylcysteine Against Ischemia-reperfusion Injury On The Liver

Objective:To investigate the protective effect of N-acetylcysteine (NAC) against ischemia-reperfusion injury and the possible mechanism.Methods:Fourty patients needed to block porta hepatis undergoing liver operation, were randomly allocated into two groups (n=20 each): (1)normal saline were given(Group A); (2)150mg/kg NAC were given IV during operation(Group B). The levels of MDA,SOD,NO and TNF-a were measured before porta hepatic blocking(T0),thirty minutes after porta hepatic blocking(T1), 1 hour(T2), 6 hours(T3), 24 hours(T4)after porta hepatic opening. The liver function variables including ALT,AST were measured before operation, 6 hours and 24 hours after porta hepatic blocking.Results:The operation time, the amount of bleeding and the blocking time have no significant difference in two groups. Compared with T0, the levels of ALT,AST, MDA,SOD,NO and TNF-a in other time points were significantly increased(P<0.05) in three groups. ALT,AST were significantly higher at T2 than other time points(P<0.01), MDA,SOD,NO andTNF-a were significantly higher at T3 than other time points(P<0.01). The variations were significantly lower in group B than in group A(P<0.05). Compared with group B, the levels of ALT,AST at T2, MDA,NO and TNF-a at T3 were significantly different in groupA (P<0.05).Conclusion : Administrating N-acetylcysteine before operation can obviously inhibit the ischemia-reperfusion injury in the liver. The possible mechanism are related with eliminating oxygen free radical, enhancing the concentration of NO and inhibiting inflammatory response. N-acetylcysteine infusion at 150mg/kg provides better protective effects than the contrast and can be safely applied in clinic.