缺血后处理对鼠肺缺血-再灌注损伤中氧化状态的影响

目的 研究缺血后处理对于肺缺血-再灌注损伤早期内源性氧化/抗氧化系统及一氧化氮水平的影响.方法 24只雄性SD大鼠,分为假手术组(S),缺血-再灌注组(I/R)以及缺血后处理组(IPO)(每组8只),分别检测肺组织中谷胱甘肽(GSH)、丙二醛(MDA)及一氧化氮(NO)的水平;黄嘌呤氧化酶(XO)及髓过氧化物酶(MPO)的活性;抗氧化酶包括:超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化酶(GPX)的活性.结果 IPO组与I/R组相比较,其抗氧化系统:SOD(41.4±4.4)U/mg vs(19.6±2.8)U/mg、CAT(19.5±1.6)U/mg vs(8.4±0.8)U/mg、GPX(168±13)U/mg vs(72±8)U/mg)和GSH(1.72±0.26)mg/g vs(0.89±0.07)mg/g蛋白的水平明显升高(均P＜0.05);氧化状态指标:XO(50±6)U/g vs(83±8)U/g,MPO(5.0±0.5)U/g vs(7.6±0.7)U/g和MDA(0.91±0.08)nmol/mg vs(1.58±0.17)nmol/mg的水平显著降低(均P＜0.05);并且内源性NO[(93±7)μmoL/g vs(22±4)μmol/g]的水平也明显升高(P＜0.01).结论 在再灌注初期的后处理可以减轻肺缺血-再灌注损伤,其保护作用一定程度上是通过抑制氧化剂的产生以及氧化作用,并且内源性NO也许和后处理的保护作用有关.

Modulation of lung oxidant/antioxidant status by ischemic post-conditioning during ischemia/ reperfusion injury: experiment with rats

Objective To investigated the effects of ischemic post-conditioning (IPO) on the lung endogenous oxidant-antioxidant system and nitric oxide level during the early stage of ischemia/reperfusion (I/R) injury.Methods Twenty four male Sprague-Dawley rats were randomly divided into 3 equal groups:sham-operation(S) group,I/R Group,undergoing ischemia by blocking the lung hilus for 1 h and then reperfusion for 30 min,IPO Group,undergoing blocking the lung hilus for 1 h and then 3 cycles of 10 s ischemia and 10 s reperfusion.Then the rats were killed with their lungs taken out.The levels of glutathione (GSH),nitric oxide(NO),malondialdehyde (MDA),xanthine oxidase(XO),and endogenous antioxidant enzymes,i.e,superoxidase dismutase (SOD),and catalase (CAT),and activities of guhathionine peroxidase (GPX) and myeloperoxidase (MPO),a neutrophil accumulation marker,were measured respectively.Results In IPO group,Compared with I/R group,antioxidant systems such as The levels of SOD,CAT,GPX,and GSH of IPO Group were (41.4 ±4.4) U/mg,(19.5 4±1.6)U/mg,(168±13) U/mg,and (1.72±0.26) U/g,all significantly higher than those of I/R Group[(19.6±2.8) U/mg,(8.4±0.8) U/mg,(72±8) U/mg,and (0.89±0.07) mg/g respectively,all P<0.05);and the levels of XO,MPO,and MDA of Group IPO were (50±6) U/g,(5.0±0.5) U/g,and (0.91±0.08) nmol/mg respectively,all significantly lower than those of I/R Group[(83±8) U/g,(7.6±0.7)U/g and (1.58±0.17) nmol/mg respectively,all P<0.05).The endogenous NO level of IPO Group was (93±7) umol/g,significantly hisher than that of I/R Group [(22±4) umol/g,P<0.01].Conclusion Post-conditioning at onset of reperfusion reduces lung I/R injury.The lung protection of IPO may be mediated,in part,by inhibiting the oxidant generation and oxidizing,and may be associated with the increasing of the endogenous NO level.