大鼠脑出血后血肿周围凝血酶与脑细胞凋亡和脑水肿的关系

目的 研究大鼠脑出血后血肿周围脑组织中凝血酶的变化及其与脑细胞凋亡和脑水肿的关系.方法 105只成年雄性SD大鼠随机均分为脑出血组、生理盐水组和正常对照组.每组再随机均分为7个时相,分别为6 h、12 h、24 h、48 h、3 d、5 d、7 d;用立体定向脑内注射法制备脑出血模型;用ELISA法检测脑组织中凝血酶-抗凝血酶复合物的含量;用流式细胞仪检测脑细胞的凋亡率;用干-湿重法检测脑组织的含水量;用透射电镜观察脑组织的形态学变化.结果 制备动物模型后,脑出血组各时相血肿周围脑组织中凝血酶含量、脑细胞凋亡率、脑组织含水量均明显高于生理盐水组和正常对照组;血肿周围脑组织中凝血酶-抗凝血酶复合物的含量与脑细胞凋亡率和脑组织含水量之间均呈正相关;电镜下,在脑出血组各时相脑组织切片中均可见大量的脑细胞凋亡和毛细血管周围大片组织间隙水肿,以及神经纤维脱髓鞘改变.结论 脑出血后,血肿周围脑组织中凝血酶含量明显升高,可导致脑细胞凋亡和脑水肿,凝血酶的含量与脑细胞凋亡率和脑组织含水量呈正相关;尽早清除血肿有望改善凝血酶引起的继发性脑损伤.

The relationship between thrombin and apotosis of brain cells and brain edema around the hematoma after intracerebral hemorrhage in rats

Objective To study the development of thrombin (TB) following experimental intracetebral hemorrage(ICH) in rats, and to analyze the relationship between TB and the apoptosis of brain cells as well as brain edema around the hematoma. Method 105 adult male SD rats were randomly divided into 3 groups:ICH group,physiological saline group and normal control group. Each of the three groups was randomly divided into 7 time phases:6 h, 12h,24h, 48 h,3 d, 5 d and7 d. A model of ICH was established by using stereotactical injection technique Thrombin-anti-Thrombin(TAT) complex in brain tissue around the hematoma was determined with ELISA assay, the brain cell apoptosis rate was analyzed by flow cytometry, the brain moisture rate observed with a dry -wet -weighing technique, and the morphological change observed with electron microscope. Results (1) At 6th hour after ICH model finished, the concentration of TAT and the apoptosis rate of brain cells around hemaotoma in ICH group was obviously higher than that in physiological saline group and that in normal control group(P <0. 05);at the phase of 48th hour after ICH model finished, they reached their maximum(P <0.01); on the 3rd day, they began reducing(P <0.01);on the 7th day, they were still higher than that in the other two groups(P <0.01). (2)At 6th hour after ICH model finished, the brain moisture rate around hematoma in ICH group was obviously higher than that in the other two groups(P <0.05); on the 3rd day, it got to its maximum(P <0. 01); on the 7th day, it began going down(P <0.01) ,and was still remarkably higher than that in the other two groups(P <0.01). (3)There was a significant correlation between the concentration of TAT and the apoptosis rate of brain cells, and the brain moisture rate in ICH group(r :0.627,0.315; both of P <0.01). (4) Using electron microscope,we observed brain cells apoptosis , remarkable edema around capillary vessel, and nerve fiber demyelination ;These changes in ICH group were obviously more than that in the other two groups. Conclusions FollowingICH, the concentration of TB, the apoptosis rate of brain cells, and the brain moisture rate around hematoma go up and exhibited with timedepended change. TB may result in brain cells apoptosis and brain edema(vasogenic brain edema). If the hematoma were removed earlier , it may be improved that the problem of secondary brain injury result from TB.