丁苯酞联合肢体缺血后处理对脑缺血再灌注损伤大鼠的保护作用

Protection of Dl-3-n-Butylphthalide and limb ischemic postconditioning against cerebral ischemia reperfusion injury in rats

目的:研究丁苯酞联合肢体缺血后处理(Limb ischemic postconditioning,LPostC)治疗大鼠脑缺血再灌注损伤的效果。方法:选取75只雄性SD大鼠随机分为假手术组(Sham组)、缺血再灌注组(I/R组)、丁苯酞(Dl-3-n-Butylphthalide,NBP)后处理组(NBP组)、肢体缺血后处理组(LPostC组)和同时予NBP+LPostC的联合后处理组(NL组),每组15只。采用石蜡线栓法建立大鼠大脑中动脉缺血再灌注模型;以夹闭双侧股动脉5 min、松开5 min为一次循环,重复3次进行LPostC处理。NBP组和NL组大鼠分别于脑缺血2 h后腹腔注射丁苯酞80 mg•kg-1,剩余各组大鼠腹腔注射等体积生理盐水。再灌注24 h后,运用分光光度计法测定脑组织中丙二醛(Malondialdehyde,MDA)和超氧化物歧化酶(Superoxide dismutase,SOD)水平;以免疫组化测定脑组织半胱氨酸蛋白酶Caspase-3和Caspase-9的表达。结果:与Sham组相比,I/R组SOD活性降低,MDA含量增加,Caspase-3和Caspase-9表达明显升高(P<0.05)。与I/R组相比,NBP组、LPostC组和NL组MDA含量降低且SOD活性升高,Caspase-3和Caspase-9的表达明显降低(P<0.05)。与NBP组和LPostC组比较,NL组MDA含量更低且SOD活性更高,Caspase-3和Caspase-9的表达更低(P<0.05)。结论:丁苯酞后处理和肢体缺血后处理的神经保护作用可能与抑制氧化应激和减少细胞凋亡有关;且联合应用的保护效果优于两者单独应用。

Objective:To investigate the protection of Dl-3-n-Butylphthalide and limb ischemic postconditioning(LPostC)against cerebral ischemia reperfusion injury in rats.Methods:Seventy-five male Sprague Dawley(SD)rats were randomly divided into sham-operation(Sham)group,ischemia reperfusion(I/R)group,Dl-3-n-Butylphthalide postconditioning(NBP)group,limb ischemia postconditioning(LPostC)group and NBP+LPostC(NL)group(n=15).I/R model was established by line embolism with paraffin to block the middle cerebral artery.LPostC was induced via three cycles of bilateral femoral artery occlusion and non-occlusion.After 2 h of ischemia,the NBP and NL groups were intraperitoneal injected with butylphthalide 80 mg•kg-1 immediately,and the remaining groups were given an equal volume of normal saline.After 24 h reperfusion,spectrophotometer was used to measure malondialdehyde(MDA)content and superoxide dismutase(SOD)activity in brain tissue.Immunohistochemistry was used to measure Caspase-3 and Caspase-9 levels.Results:The SOD activity was lower whereas MDA content was higher in I/R group than that in Sham group,meanwhile the expression of Caspase-3 and Caspase-9 increased (P<0.05). Compared with I/R group, SOD activity increased and MDA content decreased in NBP group, LPostC group and NL group, and the expression of Caspase-3 and Caspase-9 decreased (P<0.05). Compared with NBP group or LPostC group, NL group had higher SOD activity and lower MDA content, and the expression of Caspase-3 and Caspase-9 were lower (P<0.05). Conclusion: Dl-3-n-Butylphthalide postconditioning and LPostC have a certain protective effects on cerebral ischemia-reperfusion injury, and the mechanism may be related to the inhibition of oxidative stress and apoptosis;and the protective effect of the combined application is better than each alone.