脑出血后水蛭素干预对水通道蛋白4表达的影响

Effect of hirudin intervention on expression of aquaporin-4 after intracerebral hemorrhage

目的:在脑出血后不同时段应用凝血酶抑制剂水蛭素干预,观察其对脑水肿、水通道蛋白4(aquaporin-4,AQP4)及其mRNA表达的影响。方法:将40只健康雄性大鼠随机分为4组,每组10只,采用自体动脉血注入尾状核法制成大鼠脑出血模型,其中1组作为对照组,造模后不予水蛭素干预,另3组分别于造模后6h、12h、18h在血肿内注入水蛭素进行干预,32h后提取脑组织,应用反转录聚合酶链反应(RT-PCR)检测AQP4mRNA在脑水肿组织的表达,并采用Western blot和免疫组化检测AQP4蛋白在脑水肿组织中的表达,同时用干重、湿重法计算脑组织含水量来表示脑水肿程度。结果:与对照组相比,凝血酶抑制剂水蛭素能减轻脑出血后脑组织的水肿程度,并降低脑组织中AQP4mRNA及AQP4蛋白的表达,在6h和12h干预组中其抑制作用最为明显(P<0.05),且AQP4mRNA及AQP4蛋白的表达减少与脑水肿变化趋势一致。18h干预组的脑水肿程度、AQP4mRNA及AQP4蛋白的表达虽有低于对照组的趋势,但差异无统计学意义。结论:脑出血后,凝血酶抑制剂水蛭素能减少脑组织水肿的程度、降低AQP4mRNA和AQP4蛋白的表达,水蛭素干预组中以6h及12h干预组的作用最为明显。

Objective To investigate the effect of thrombin inhibitor, hirudin, on brain edema and expression of aquaporin-4 （AQP4） after intracerebral hemorrhage. Methods Forty male Wistar rats were randomly divided to 4 groups. Self nonheparinized fresh blood was injected into nucleus caudate to construct intracerebral hemorrhage model. No intervention was transected in the control group, while in the other three groups hirudin solution was injected into the hematoma at 6, 12 and 18 h, respectively, as intervention. The brain tissue was taken at 32 h and the expressions of AQP4 mRNA and AQP4 protein were determined by RT-PCR and Western blot, respectively： the wet and dry weight of the brain tissue was determined to assess the degree of brain edema. Results Compared with the control group, thrombin inhibitor hirudin intervention ameliorated the brain edema and decreased the expression of A QP4 mRNA and AQP4 protein after intracerebral hemorrhage. This effect was most prominent in 6 h and 12 h intervention groups （P〈0.05）. Although difference was also seen between control group and 18 h intervention group, yet it was not statistically significant. Conclusions Hirudin intervention could reduce the brain edema and suppress the expression of AQP4 mRNA and AQP4 protein in brain tissues after intracerebral hemorrhage, especially given within 6 h and 12 h after formation hematoma.