缩宫素对大鼠肝脏缺血-再灌注损伤的保护作用及其机制

The protective effect and mechanism of oxytocin on hepatic ischemia-reperfusion injury in rats

目的探讨缩宫素对大鼠肝脏缺血-再灌注(I-R)损伤的保护作用及可能的机制。方法将48只雌性SD大鼠随机均分为假手术(S)组、I-R组和缩宫素处理(OT)组。建立大鼠70%I-R模型,缺血时间1 h。OT组分别于术前12 h,15 min及再灌注时经腹腔注射缩宫素0.5 mg/kg,S组及I-R组在相同时间注射等量生理盐水。各组大鼠分别于肝脏再灌注后2和6 h处死,取肝脏及血液标本,检测血清谷丙转氨酶(ALT)、谷草转氨酶(AST)、肿瘤坏死因子α(TNF-α)以及肝脏组织超氧化物歧化酶(SOD)、髓过氧化物酶(MPO)的活性及丙二醛(MDA)含量,并分别检测肝组织中核因子κB(NF-κB)的表达和肝脏组织的病理改变。结果与I-R组相比,OT组的ALT、AST、TNF-α水平及MPO、NF-κB阳性表达明显降低(P<0.05),肝脏病理损伤较轻,但是MDA及SOD变化不明显。结论缩宫素对大鼠肝脏I-R损伤具有保护作用。其机制可能与抑制炎症因子产生及活化有关。

Objective To investigate the protective effect and mechanism of oxytocin against hepatic ischemia-reperfusion（I-R） injury in rats.Methods Forty-eight SD female rats were randomly divided into 3 groups of sham operation（S）,I-R and oxytocin treatment（OT） with 16 rats each.The model of 70% hepatic I-R was established by 1 h ischemia in groups of I-R and OT.Group OT was administered intraperitoneally OT 0.5 mg/kg at 12 h and 15 min before ischemia and immediately after reperfusion.Rats were killed at 2,6 h after reperfusion.The serum tumor necrosis factor-α（TNF-α） and transaminases（ALT,AST） were assayed.The superoxide dismutase（SOD）,malondialdehyde（MDA） and myeloperoxidase（MPO） in liver tissues were measured.The expression of nuclear factor kappa B（NF-κB） in liver tissue was determined by immunohistochemistry,and histologic changes were observed by HE staining.Results Compared to group I-R,group OT was associated with lower serum ALT and AST,MPO activity,NF-κB expression（P0.05）.The injury of liver tissue in group OT was slighter.However,oxytocin treatment has litter effect on MDA and SOD activities（P0.05）.Conclusion The results suggest that oxytocin has a protective effect on hepatic I-R injury in rats.The mechanism of protection appears to be associated with its inhibiting the expressions of inflammatory cytokines.