Protective effects of 17β-estradiol on ischemia-reperfusion injury in rat orthotopic liver transplantation

Objective To observe the effect of 17β-estradiol (E2) on ischemia-reperfusion injury (IRI) in rat orthotopic liver transplantation.Methods Thirty-six SD male rats were randomized into three groups:sham group,I/R group,I/R + E2 group.The rate in I/R group and I/R + E2 group were subjected to liver transplantation by modified two-cuffed methods.Six h after reperfusion,the recipients were sacrificed.The levels of ALT,AST and MDA were measured.Liver ultrastructures were observed under the electron microscopy.The levels of tumor necrosis factor ( TNF)-α were detected by using immuneohistochemistry.Results In I/R group and I/R + E2 group,the levels of ALT ( 950.83 ± 65.20 ) U/L and (271.67 ±22.29) U/L,AST (2436.67 ±89.70) U/L and ( 1152.83 ±85.37) U/L and MDA (0.63 ±0.03) nmol/mg and (0.40 ±0.02) nmol/mg protein were significant higher than in sham group (60.32 ±7.31 ) U/L,(38.12 ±4.33 ) U/L,and (0.30 ±0.04) nmol/mg protein,respectively ( all P ＜0.05 ),especially higher in I/R group.Immunohistochemistry revealed the the levels of TNF-α were highest in I/R group,and those of TNF-α in I/R + E2 group were lower than in I/R group.Under the electron microscopy,the injury of hepatocytes in I/R group was significantly severer than in I/R + E2 group.Conclusion Estradiol can decrease ischemia-reperfusion injury in rat liver transplantation probably by decreasing the levels of TNF-α and MDA. Key words: Liver transplantation;  Ischemia;  Reperfusion injury;  17β-Estradiol