胃酶抑素A通过上调p-ERK1/2的表达来保护大鼠脑缺血再灌注损伤

目的 探讨胃酶抑素A(Pepstatin A)保护大鼠脑缺血再灌注损伤的潜在机制。方法 将48只成年雄性健康Sprague-Dawley大鼠随机分配至假手术组(16只)、生理盐水对照组(16只)及Pepstatin A干预组(16只); 大鼠大脑中动脉缺血再灌注模型遵照Zea longa线栓法制备,即缺血2 h即恢复血流灌注,再灌注24 h后处死大鼠; 干预组及对照组在脑缺血再灌注即刻分别经腹腔注射Pepstatin A配置液(0.2 mL/10 g)或等体积生理盐水; 脑缺血2 h再灌注24 h时采用标准评分法行神经功能缺损评分; 假手术组、对照组及干预组中随机各取8只检测脑梗死体积,余下8只大鼠行western blot检测p-ERK1/2及Caspase-3的表达水平。结果 神经功能缺损评分显示,假手术组大鼠行为学表现正常,评分为0分,干预组大鼠的评分均显著低于对照组(P<0.05)。TTC染色显示,假手术组脑组织无梗死灶,干预组大鼠的相对脑梗死体积显著低于对照组(P<0.05)。Western blot检测显示,对照组p-ERK1/2蛋白的表达水平显著高于假手术组(P<0.05); 干预组该蛋白的表达水平较对照组显著增加(P<0.05); 干预组Caspase-3蛋白的相对表达水平显著低于对照组(P<0.05)。结论 Pepstatin A可能通过上调p-ERK1/2的表达来减少脑梗死体积及细胞凋亡发生,从而保护大鼠脑缺血再灌注。

Pepstatin A can protect against cerebral ischemia-reperfusion in Rat by upregulating the expression of p-ERK1/2

ObjectiveTo investigate the neuroprotective mechanism of pepstatin A for cerebral ischemia-reperfusion injury in rat.Methods Forty-eight adult male healthy Sprague-Dawley rats were randomly divided into three groups: sham operation group(n=16), saline control group(n=16)and pepstatin A intervention groups(n=16). The Zea longa suture method was used to make the model of middle cerebral artery ischemia-reperfusion in rats. After 2 h of ischemia, reperfusion was resumed, then the rats were sacrificed at 24 h after reperfusion. The corresponding doses of pepstatin A(0.2 mL/10g)or the same volume of saline were injected intraperitoneally at the time of ischemia for 2 h and reperfusion in the pepstatin A intervention group and the saline control group. Longa's of five standard scoring method was used to evaluate the neurological deficit of the rats at ischemia for 2 h and 24 h after reperfusion. Eight rats were choosed randomly from eath groups of the sham operation group, saline control group and pepstatin A intervention group to detect the infarct volume. Western blot was used to detect the expression of p-ERK1/2 and Caspase-3 in the remaining eight rats.Results The neurological deficit score was 0 in the sham operation group because their behavior is normal. The neurological deficit score in the pepstatin A intervention group was significantly lower than saline control group(P<0.05). TTC staining showed that there was no infarction in the brain tissue of the sham operation group. The relative infarction volume in the pepstatin A intervention group was significantly lower than the saline control group(P<0.05). The expression level of p-ERK1/2 in the pepstatin A intervention group was significantly more than the saline control group(P<0.05). Compared with the saline control group, the expression level of this protein was significantly increased in the pepstatin A intervention group(P<0.05). The relative expression level of Caspase-3 in the pepstatin A intervention group was significantly lower than that in the saline control group.Conclusion Pepststin A could upregulate the expression level of the p-ERK1/2 possibly, to reduce brain infarction volumes and cell apoptosis, then protect the cerebral ischemia reperfusion rats.