Effect of methylene chloride upon hepatic ischemic reperfusion injury

Abstract

To investigate the effects and mechanisms of methylene chloride (MC) in hepatic ischemic reperfusion injury. Eighty SD-rats were divided equally into 4 groups: control group (n = 20), donors without any treatment; CoPP group (n = 20), donors injected with CoPP (5 mg/kg, ip) at 24 h; ZnPP group (n = 20), donors injected with ZnPP (20 mg/kg, ip) at 24 h; MC group (n = 20), donors fed with MC (500 mg/kg) per day for 7 days before graft procurement. Syngeneic orthotopic liver transplantation was performed in rats with modified Kamada's two-cuff technique. And SD rats were used as donors (n = 10)and recipients respectively. 5 recipients in each group were sacrificed and the grafts were procured at day 3 after transplantation, the post-operative survival time was observed in the remnant. The tests were determined as following: the level of serum ALT, AST in recipients; heme oxygenase-1 (HO-1) expression of graft was tested by immunohistochemistry and Western blot; the index of graft apoptosis examined by TUNEL method; the pathology of graft assessed by Suzuki's criteria. The level of serum ALT [(65 +/- 28) U/L], AST [(187 +/- 43) U/L] in CoPP and ALT [(75 +/- 16) U/L], AST [(185 +/- 42) U/L] in MC group was significantly lower than that ALT [(346 +/- 45) U/L], AST [(474 +/- 90) U/L] in control group and ALT [(578 +/- 75) U/L], AST [(1084 +/- 128) U/L] in ZnPP group (P < 0.01). The median expression of HO-1 in MC group was no significantly different with that in control group (P > 0.05). While the median expression of HO-1 in CoPP group was higher than that in control group (P < 0.05). The index of graft apoptosis in MC group and CoPP group, 4.1% +/- 0.6% and 3.2% +/- 0.8% respectively, was significantly lower than that (12.5% +/- 2.4%) in control group and (25.8% +/- 3.1%) in ZnPP group (P < 0.05). Compared with the other two groups, MC and CoPP groups had lesser neutrophil infiltration and a lower grade of hepatocytic injury in grafts. Suzuki's scores in grafts of MC and CoPP groups were lower than that in control and ZnPP groups (P < 0.05). The median post-transplantation survival time of the recipients in MC and CoPP groups was 100 and 93 days respectively while that in control and ZnPP groups was 85 and 12 days (P < 0.05). Over-expression of HO-1 and MC both have protective effects in hepatic ischemic reperfusion injury.