依达拉奉对脑缺血-再灌注损伤大鼠的抗细胞凋亡与神经保护作用

Anti-apoptotic and Neuroprotective Effects of the Antioxidant Edaravone in Rats Subjected to Cerebral Ischemia-Reperfusion Injury

目的研究自由基清除剂依达拉奉对脑缺血-再灌注损伤大鼠的抗细胞凋亡和神经保护作用。方法采用线栓法制备大鼠大脑中动脉缺血-再灌注模型。将SD大鼠分为假手术组、再灌注组和依达拉奉组。再灌注组和依达拉奉组按再灌注2,6,12,24,48 h分为5个亚组。依达拉奉组在缺血2 h后解除栓塞,给予依达拉奉3 mg.kg-1静脉注射,首次给药24 h后相同剂量再次给药。再灌注组给予0.9%氯化钠溶液,给药剂量、时间和方法同依达拉奉组。应用硫代巴比妥酸(TBA)比色法检测各组血清丙二醛(MDA)浓度,免疫组化染色及原位细胞凋亡检测法(TUNEL法)测定脑组织bcl-2蛋白表达和凋亡细胞数,并测量各组脑梗死体积。结果依达拉奉组再灌注后6,12,24,48 h的梗死体积、血清MDA浓度、TUNEL阳性细胞数均明显小于再灌注组(均P<0.05),各时间点bcl-2蛋白表达均高于再灌注组(P<0.01)。结论依达拉奉可以降低羟自由基水平,对抗细胞凋亡,对脑缺血-再灌注损伤大鼠有明显保护作用。

Objective To study the antiapeptotic and neuroprotective effects of the antioxidant edaravone in rats with a model of iscbemia-reperfusion injury. Methods 84 SD rats were randomly divided into 3 groups： （1）the sham operation group （ n = 4 ） , （2） ischemia-reperfusion （IR） group（ n = 40 ） , and （3） edaravone treatment group （ n = 40 ）. A model of cerebral ischemia-reperfusion injury was set up in each of the rats of groups （2） and group （3） by suture-tying and untying the middle cerebral artery. Rats of group（2） and group（3） were further divided into 2, 6, 12, 24 and 48 hour subgroups according to the time of reperfusion. Rats of group（3） were given each an Ⅳ injection of 3 mg·kg^-1 of edaravone following the 2 hour ischemia. 24 h later a second injection of the same close of edaravone was given to each of the rats of group（3） by the same route. Rats of group（3） were given each injections of equivalent amounts of physiologic saline solution at the same times and in the same manner as described above. The serum concentration of malonyldialdehydc（MDA） was determined with the colorimetric method. Bcl-2 immunohistocbemical method and TUNEL staining were used to determine the expression of the bcl-2 protein and number of TUNEL-pesitive apeptotic cells in the brain tissue. The sizes of the brain infarction were assessed as well. Results After 6, 12,24 and 48 hours of reperfusion, the sizes of brain infarction in rats of group（3） treated with edaravone were obviously smaller than those in rats of group（2）（ P 〈 0.05 ）, and the serum MDA concentrations in rats of group（3） were significantly lower than those in rats of group（2） （P 〈0.05）. In addition, there was an evident increase in the expression of bcl-2 protein （P 〈0.01 ） and a striking decrease in the number of TUNEL -positive apeptotic cells in the brain tissue of the rats in group（3） treated with edaravone as compared with those in rats of group（2） at the same time points （ P 〈 0.01 ）. Conclusion Edaravone was shown to have an excellent neuroprotective effect in rats subjected to an ischemia-reperfusion brain injury possibly by scavenging free radicals and a bcl-2 dependent anti-apeptotic mechanism.