亚低温治疗对高血压脑出血后水通道蛋白-4表达的影响

Effect of Mild Hypothermia Therapy on Expression of Aquaporin-4 in Rats with Hypertensive Intracerebral Hemorrhage

目的探讨亚低温治疗对大鼠高血压脑出血后血肿周围脑组织水通道蛋白-4(AQP-4)表达的影响。方法将制成高血压脑出血模型的大鼠随机分为亚低温治疗组(40只)和常温对照组(10只),其中治疗组又根据从发病至亚低温治疗的时间间隔分为2、4、8、12h四个亚组,每亚组10只动物。大体观察动物行为学变化,3d后处死动物取脑组织进行脑含水量测定(干湿重法)及AQP-4表达的测定。结果对照组的脑含水量为(89.16±0.48)%,治疗组中出血后2h、4h和8h三个亚组的脑含水量分别为(81.42±0.58)%、(83.86±0.28)%和(86.95±0.29)%,与对照组相比有显著性差异(P<0.05),而出血后12h亚组的含水量与对照组相比无显著性差异(P>0.05)。对照组AQP-4的表达(以吸光度表示)明显高于出血后2h、4h及8h三个亚组(P<0.05),与出血后12h亚组相比无显著差别(P>0.05)。结论本研究提示高血压脑出血后早期应用亚低温治疗可以下调AQP-4的表达,并可有效控制脑水肿的发生。

Objectives To explore the effect of mild hypothermia therapy on the expression of aquaporin-4 （AQP-4） in the rats with hypertensive cerebral hemorrhage（HICH）. Methods Fifty rats with HICH were randomly divided into both the experimental group （n=40）, where the rats were treated with mild hypothermia, and the control group （n=10）, where the rats were treated with normal temperature. Forty rats with HICH in the experimental group were redivided into 4 subgroup of 10 rats each, where the mild hypothermia therapy began 2, 4, 8 and 12 hours respectively after HICH. The water content of the cerebral tissues and expression of AQP-4 in the cerebral tissues around the hematomas were determined respectively by dry-wet weight method, and immunohistochemical technique 3 days after HICH. The change in the neurological behavior was observed after HICH in all the rats. Results The water content of the cerebral tissues and the level of AQP-4 expression in the control group were significantly higher than those in the experimental subgroups where the mild hypothermia therapy began 2, 4 and 8 hours after HICH （P〈0.05）, but they were insignificantly higher than those in the experimental subgroup where the mild hypothermin therapy began 12 hours after HICH （P〉 0.05）. Conclusions It is suggested that the expression of AQP-4 can be downregulated, and the cerebral edema can be significantly attenuated by the mild hypothermia therapy in the rats with HICH.