雌激素对大鼠肝缺血再灌注损伤中SOD和MDA及细胞凋亡的影响

Effects of estrogen on SOD and MDA and apoptosis in hepatic ischemia-reperfusion injury of rats

目的:探讨雌激素对大鼠切除肝缺血再灌注损伤的肝脏超氧化物歧化酶(SOD)、丙二醛(MDA)及细胞凋亡的影响。方法:制作肝切除缺血再灌注损伤动物模型,雄性SD大鼠随机分为3组,即假手术组(Sham组),肝切除缺血再灌注组(I/R组)和肝切除缺血再灌注+雌激素组(I/R+E2组)。分别在缺血再灌注后1、3、6 h于光学显微镜下观察肝组织病理学改变,检测血清ALT的水平、肝组织MDA的含量及SOD的活性,并应用流式细胞仪检测细胞凋亡率。结果:I/R+E2组在各时相点血清ALT、肝组织MDA和SOD及肝细胞凋亡率的变化幅度明显低于I/R组。在光学显微镜下观察I,/R组肝小叶结构紊乱,肝窦淤血,肝细胞水肿变性,肝细胞片状坏死。Sham组和I/R+E2组上述改变明显减轻。结论:雌激素对肝切除缺血再灌注损伤有显著保护作用,其作用机制可能与雌激素减少氧自由基产生、减轻脂质过氧化反应及抑制细胞凋亡有关。

Objective： To investigate the effects of estrogen on supemxide disnlutase（SOD）,malondialdehyde（MDA） and apoptosis in hepatic ischemia reperfusion injury of rats.Methods： Models of rats with hepatic ischemia-reperfusion were established.Male S-D rats were randomly divided into three group： sham group,I/R group and I/R＋E2 group.After 1,3 and 6 h of reperfusion,alanine aminotransferase in the serum were observed;the superoxide dismutase（SOD） activity and levels of malondialdehyde（MDA） in the hepatic tissue were detected;histologic changes of liver were compared;cell apoptosis were measured by flow cytometry.Results： The levels of ALT,MDA and cell apoptosis index in I/R＋E2 group were lower than that in I/R group,but the activity of SOD increased.The obvious ischemia-reperfusion injury was observed under light microscope in I/R group,including congestion in liver sinusoids,hepatocyte swelling,inflammatory cell infiltration and necrosis of hepatocytes in some areas of the livers.In Sham group and I/R＋E2 group,hepatic tissue injury was significantly improved.Conclusions： Estrogen significantly protects liver from hepatic ischemia-reperfusion injury.The mechanism of protection may be associated with its scavenging of radical,inhibition of lipid peroxidation and decrease of the hepatocellular apoptosis.