老年大鼠大脑中动脉永久性缺血与缺血再灌注对大脑损伤的比较研究

Comparison of middle cerebral artery permanent ischemia and ischemia reperfusion in aged rats

目的探讨老年大鼠缺血再灌注对大脑的影响。方法将30只健康雄性老年(18~20月龄)SD大鼠随机分为假手术组(Sham组)、永久性缺血组(I组)及缺血再灌注组(I/R组),除Sham组外,其余两组采用线栓法复制老年大鼠大脑中动脉局灶缺血再灌注损伤模型。术后24 h,2,3,5-氯化三苯基四氮唑检测大鼠脑梗死体积,ELISA法检测脑组织高迁移率族蛋白-1(HMGB1)和丙二醛(MDA)含量及超氧化物歧化酶(SOD)活性,Western blotting检测脑组织HMGB1的表达。结果与Sham组比较,I组脑梗死体积增加,SOD活性降低(P <0.05),MDA含量和HMGB1相对表达量升高(P <0.05)。与I组比较,I/R组大鼠脑梗死体积百分比减少,SOD活性上升(P<0.05),MDA含量和HMGB1相对表达量下降(P<0.05)。结论与永久性缺血相比,老年大鼠大脑中动脉缺血再灌注可减轻大脑损伤。

Objective To study the effect of ischemia/reperfusion on brain in aged rats. Methods Thirty male aged SD rats (18 to 20 months) were randomly divided into 3 groups: sham operation group (Sham group), permanent ischemia group (I group), ischemia/reperfusion group (I/R group). Except the Sham group, the other groups were established by using ligation of middle cerebral artery. Twenty-four hours after the operation, cerebral infarction volume was detected by TTC staining;the activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) were measured by ELISA test;the expression of high mobility group protein 1 (HMGB1) was examined by ELISA test and western blot analysis. Results Compared with Sham group, cerebral infarction volume was increased, SOD activity and cerebral blood flow were decreased (P < 0.05), the level of MDA and the expression of HMGB1 were up-regulated in I group (P < 0.05). Compared with I group, cerebral infarction volume was decreased, SOD activity was increased (P < 0.05), the level of MDA and the expression of HMGB1 were downregulated (P < 0.05) in I/R group. The differences were statistically significant. Conclusions Compared with middle cerebral artery permanent ischemia, the brain damage could be alleviated after middle cerebral artery ischemia/ reperfusion in aged rats.