雌激素对肠缺血再灌注损伤时MDA、MPO影响的研究

Protective effect of estrogen on intestinal ischemia-reperfusion injury in pubertal rats and its possible action on MPO and MDA

目的探讨雌激素对肠缺血再灌注损伤(I/R)的保护作用以及对MDA含量、MPO活性的影响。方法选择青春期大鼠60只,随机分为4组(n=15)。假手术组未切除卵巢,其余3组行双侧卵巢切除术,术后隔天分别皮下注射蓖麻油(对照组)、雌二醇(E2,100μg/kg,E2组)、高剂量雌二醇(E2,500μg/kg,5E2组),连续4周。各组均行肠系膜上夹闭30min,再灌注时间分别为1h(n=5)、6h(n=5)和24h(n=5)。采集血清标本测定E2浓度、血清MDA含量、MPO活性;采集组织标本测定MPO活性。结果对照组、假手术组、E2组和5E2组的血清雌二醇浓度依次增加,差异有统计学意义(P<0.01)。对照组术后MPO活性、MDA值含量高于术前,而其他3组术后MPO活性、MDA含量低于术前。E2组的血清MPO值、MDA值与对照组、假手术组相比,差异有统计学意义(P<0.01)。结论雌激素对大鼠肠I/R损伤有保护作用,该保护作用与抑制中性粒细胞浸润、活化、减少脂质氧化程度有关。

Objective This study investigated the role of 17 beta-estradiol （E2 in intestinal ischemia-repeffusion （I/R） injury in pubertal rats and its possible effect on Myeloperoxidase （MPO） activity and Malondialdehyde （MDA）concentration in serum. Methods The 60 rats were randomly divided into 4 groups （each group,n = 15）. Rats of pubertal age were ovafieetomized and injected subcutaneously with castor oil vehicle （control group）, 100 u g / kg E2 group（E2 group）,500 u g / kg high dosage E2 group（5 E2 group） every other day for 4 weeks. Other rats of the same age underwent sham ovariectomy as sham-op group.The rats in each group were subjected to 30 minutes occlusion of superior mesenterie artery followed by 1 hour （n = 5）,6 hours （n = 5）,or 24 hours （n = 5） reperfusion. The blood samples of rats were obtained for the determination of E2 concentration, content of MDA and the activity of MPO . The activity of MPO in tissue was determinated by chemical measurement. Results The serum concentration of E2was increased from control to E〉5 E2 groups in proper order （P 〈 0.01）, Compared with control and 5 E2 group,the activity of MPO in tissue in E2 group was lower （P 〈 0.01）.The activity of MPO and content of MDA in serum after I / R injury were lower than that of MPO and MDA before I / R injury in sham-op,E：,and 5 E2 groups ,but reversely in control group .Compared with eontrol,sham-op group,the serum MPO and MDA values in E2 group were lower （P 〈 0.01）. Conclusions Estrogen may plays a protective effect on intestinal I / R injury in pubertal rats,probably by inhibiting MPO and MDA.