鼻腔给予外源性胰岛素样生长因子后成年大鼠脑梗死体积及Bcl-2蛋白表达的变化

Changes of the volume of cerebral infarction and the expression of Bcl-2 protein after the administration of exogenous insulin-like growth factor through nasal cavit in adult rats

目的:观察经鼻腔给予外源性胰岛素样生长因子对成年大鼠局灶性脑缺血后脑梗死体积及凋亡抑制基因Bcl-2蛋白表达的影响。方法:实验于2003-12/2004-05在中国医科大学动物实验室进行,取70只雄性SD大鼠随机分为4组:①正常组(n=5):不干预。②假手术组(n=5):只分离颈总动脉及颈外动脉,不插入尼龙线。③缺血组(n=30):采用线栓法制备大鼠持续性局灶性脑缺血模型,缺血后0.5h经鼻腔给予生理盐水5μL,间隔2min后再次给药,共10次50μL。缺血后24,48,72,96,120h,7d麻醉状态下处死动物。④胰岛素样生长因子组(n=30):造模同模型组,缺血后0.5h经鼻腔滴注胰岛素样生长因子50μL,给药方法和处死时间同模型组。计算各组不同时间点脑梗死灶体积、Bcl-2阳性细胞数用免疫组化方法测定。结果:经补充后70只大鼠进入结果分析。①脑梗死灶体积:缺血组24,72h最大,120h变小,7d更小犤(283.72±40.58),(288.74±42.03),(141.97±28.34),(101.28±19.42)mm3犦,胰岛素样生长因子组以上各个时间点均小于缺血组犤(202±32.66),(200.83±36.80),(98.97±32.76),(78.92±23.24)mm3,P<0.01犦。②Bcl-2阳性细胞数:正常组及假手术组未见,缺血组24h少量出现,72h达高峰,120h减少,7d更少犤(9±3),(28±3),(17±2),(3±3)个/视野犦,胰岛素样生长因子组以上各个时间点均多于缺血组犤(22±3),(37±6),(26±4),(8±3)个/视野,P<0.01犦。结论:脑缺血后经鼻腔给予胰岛素样生长因子能减少模型大鼠脑梗死灶体积,上调Bcl-2蛋白表达,抑制细胞凋亡,起到脑保护作用。

AIM： To observe the effect of the administration of exogenous insulin-like growth factor （IGF） through nasal cavit on the volume of cerebral infarction and the expression of apeptosis suppressor gene Bcl-2 protein in rats with focal cerebral ischemia. METHODS： The experiment was conducted in the Animal Laboratory of China Medical University from December 2003 to May 2004. A total of 70 male SD rat were selected and randomly divided into 4 groups： ① Normal group （n=5）： without intervention, ② Sham operated group （n=5）： common carotid artery and external carotid artery were separated, without the insert of nylon line; ③ Ischemia group （n=30）： Using line-lock method to make rat lasting focal cerebral ischemia model, 0.5 hours after ischemia 5 μL saline were given through nasal cavit, 2 minutes after administrated again totally 50 μL for 10 times. After ischemia 24, 48, 72, 96, 120 hours, and 7 days the animals were sentenced to death under the drugged state; ④ IGF group： Models were made as the model group, 0.5 hours after ischemia 50 μL IGF was dribbled through nasal cavit. The administration method and death time were the same as the model group. The focal volum of cerebral infarction at different time points was calculated, and the number of Bcl-2 positive cells was detected with immunohistochemical method. RESULTS： After supplement,70 rats were involved in the result analysis. ① The focal volume of cerebral infarction： It was the biggest at the 24^th and 72^nd hours, at the 120^th hours became small, and at the 7^th days became smaller [（283.72±40.58）, （288.74±42.03）, （ 141.97±28.34）,（101.28±19.42）mm^3]. It was less in IGF group at the above time points than that in ischemia group [（202±32.66）, （200.83±36.80）, （98.97±32.76）, （78.92±23.24）mm^3, P 〈 0.01]. ② The number of Bcl-2 positive cells： There were no Bcl-2 positive cells in normal group and sham operated group. At the 24^th hours a small quantity appeared, and at the 72^nd hours reached the peak, and at 7^th day became less [（9±3）, （28±3）, （17±2）, （3±3）per sight]. It was less in IGF group at the above time points than that in ischemia group [（22±3）, （37±6）, （26±4）, （8±3） per sight,P〈 0.01]. CONCLUSION： The administration of IGF factor through nasal cavit after the cerebral ischemia can decrease the focal volume of cerebral infarction in rat models, raise the expression of Bcl-2 protein, inhibit apeptosis and have the effect on the brain protection.