亚低温对局灶性脑缺血大鼠血管新生的影响

The effects of mild hypothermia on angiogenesis in rats with focal cerebral ischemia

目的探讨亚低温对局灶性脑缺血大鼠血管新生的影响。方法采用改良的线栓法制作大鼠永久性大脑中动脉闭塞模型，将造模成功的大鼠分为常温组和亚低温组。造模后14d通过股静脉注射异硫氰酸荧光素右旋糖酐（FITC-dextran）标记微血管，结合共聚焦显微镜和3DDoctor3．5版软件分析梗死灶周围区微血管的直径、面积及血管分支数目，并采用TTC染色观察脑梗死灶体积的变化。结果脑梗死后14d，梗死侧微血管直径明显小于对侧，但是血管分支数目及面积较对侧增加，且亚低温组梗死侧微血管直径、面积及分支数目明显大于常温组梗死侧；亚低温组梗死体积也明显小于常温组，差异均具有统计学意义（P〈0.05）。结论亚低温治疗能减小脑梗死灶体积并促进脑梗死后血管新生：

Objective To investigate the effects of mild hypothermia （MH） on angiogenesis in rats with focal cerebral ischemia （FCI）. Methods Unilateral middle cerebral artery occlusion （MCAO） models were established in male Sprague Dawley rats, which were then randomly divided into a normothermic group （N group） and a mild hypothermia group （MH group）. Microvessel diameters, numbers of branch points and vessel areas were analyzed in cerebral microvessels at the ischemic boundary perfused with fluorescein isothiocyanate （FITC） dextran on the 14th day after ischemia using laser scanning confocal microscopy （ LSCM ） and 3D Doctor 3.5 software. Infarct volumes were examined with 2,3,5 triphenyltetrazolium chloride（TTC） staining. Results Compared with the contra-lateral hemisphere, microvessel diameter was significantly decreased in the ipsilateral hemisphere at the 14th day post MCAO. The total number of branch points and vessel areas had increased in the ipsilateral hemisphere. Mierevessel diameters, the number of branch points and vessel areas were significantly increased and infarct volumes wece.signifieantly reduced in the MH group compared to the N group. Conclusion MH can reduce infarct volume and improve angiogenesis at the ischemic boundary.