胰蛋白酶抑制剂在大鼠局灶性脑缺血再灌注损伤中脑保护作用及其分子机制的研究

The Study of Effect and Mechanism of Trypsin Inhibitor on Reperfusion Injury After Cerebral Focal Ischemia

目的 研究胰蛋白酶抑制剂在大鼠局灶性脑缺血再灌注损伤中的脑保护作用及其分子机制。方法 采用线栓法建立大鼠大脑中动脉 (MCAO)缺血 1h再灌注 2 4h模型 ,2 4只雄性大鼠随机分为假手术组、生理盐水对照组和胰蛋白酶抑制剂治疗组。采用Zea -Longa评分法观察神经功能缺损程度 ,采用免疫组织化学方法、TUNEL法分别观察各组P53 蛋白表达和细胞凋亡。结果 神经功能缺失评分假手术组为 0分 ,生理盐水对照组为 2 8± 1 0分 ,胰蛋白酶抑制剂治疗组为 1 3± 0 7分 ;P53 蛋白染色阳性细胞数假手术组为 0个 ,生理盐水对照组为 12 3± 2 5个 /高倍视野 ,胰蛋白酶抑制剂治疗组为 5 5± 1 3个 /高倍视野 ;凋亡细胞数假手术组为 0个 /高倍视野 ,生理盐水对照组为 7 6± 1 0个 /高倍视野 ,胰蛋白酶抑制剂治疗组 3 5± 0 9个 /高倍视野。胰蛋白酶抑制剂治疗组各项数据均较生理盐水对照组显著减少 ( P <0 0 1)。结论 胰蛋白酶抑制剂可明显减轻局灶性脑缺血再灌注损伤 ,抑制神经细胞P53 蛋白的表达 ,抑制细胞凋亡 ,是脑保护作用的分子机制之一。

Objective To study the protective effect and molecular mechanism of trypsin inhibitor on reperfusion injury after cerebral ischemia. Methods The model of ischemia for 1h and repufusion for 24h of rat cerebrum was set by ligating MCAO described by zea-longa. 24 male rats were divided randomly into the sham operation group, the control group and trypsin inhibitor group. The presence of neurological function deficit was measured by Zea-Longa method, and the immunohistochemical staining and TUNEL were used to detect p53 protein expression and cell apoptosis in the brain tissues respectively. Results The score of neurological function deficit was zero in the sham operation group, 2 8±1 0 in the control group and 1 3±0 7 in trypsin inhibitor group. There were 12 3±2 5 p53 immunostaining positive cells in the control group and 5 5±1 3 in trypsin inhibitor group. The number of apoptotic cells was zero in the sham operation group, 7 6±1 0 in the control group, and 3 5±0 9 in trypsin inhibitor group. There was a significant difference in all above observing indices between the control group and trypsin inhibitor group(P<0 01). Conclusions Trypsin inhibitor may protect the ischemia brain from reperfusion injury, and reducing the expression of p53 protein and cell apoptosis could be one of its effective mechanisms.