地塞米松对大鼠脑出血后血肿周围细胞凋亡及半胱氨酸蛋白酶mRNA表达的影响

Effect of Dexamethasone on brain cells apoptosis around hematoma and expression of caspase-3 mRNA after intracerebral hemorrhage in rats

目的探讨地塞米松对大鼠脑出血（ICH）后血肿周围细胞凋亡及半胱氨酸蛋白酶（caspase-3）mRNA表达的影响。方法采用自体血注入法制作大鼠ICH模型;将制模成功的大鼠分为ICH组和地塞米松治疗组（治疗组）,另设假手术组,每组40只;各组大鼠分别在造模后6 h、12 h、24 h、72 h断头取脑组织行TUNEL染色及RT-PCR法检测caspase-3 mRNA的表达。结果与假手术组相比,ICH组和治疗组从6 h开始出现凋亡细胞,12~72 h逐渐增加（均P〈0.01）;与ICH组比较,治疗组12~72 h细胞凋亡数明显增多（均P〈0.01）,各时间点caspase-3 mRNA的表达均明显高于ICH组（均P〈0.01）。结论地塞米松可加重ICH后血肿周围细胞凋亡,应用地塞米松治疗ICH应慎重。

Objective To study the effect of Dexamethasone on brain cells apoptosis and the expression of caspase-3 mRNA around hematoma after intraeerebral hemorrhage （ICH） in rats. Methods ICH model was produced in adult rats by infusion of 50 μl of autologous blood into the nucleus caudatus. The ICH model rats were randomly divided into Dexamethasone treared group （treated group ） and ICH group. And propared other rats to be sham-operation group（40 rats in each group）. The brain of rats were removed at 6 h, 12 h, 24 h and 72 h after operation. The dUTP nick end labelling（TUNEL） method was used to detect DNA fragmentation and TUNEL-positive cells were quantified. RT-PCR was used to detect easpase-3 mRNA. Results Compared to sham-operation group, TUNEL-positive cells could be found at 6 h and increased gradually from 12 h to 72 h after haematoma formation both in the ICH group and the treated group（all P 〈0. 01 ）. The TUNEL-positive cells were more in the treated group at 12 h,24 h, 72 h than those in the ICH group （ all P 〈 0. 01 ）. The expression of easpase-3 mRNA was higher significantly in the treated group at 6 -72 h than those in the ICH group （all P〈 0.01 ）. Conclusion Dexamethasone can increase brain cells apoptosis around hematoma following ICH and it should be taken carefully for therapy of ICH.