2型糖尿病对鼠缺血性卒中的影响

Effect of type 2 diabetes on middle cerebral artery occlusion-induced focal cerebral ischemia

目的 研究2型糖尿病大鼠诱导血管内皮生长因子（VEGF）和血管增生作用及其在大脑中动脉局灶性脑缺血后对梗死体积、梗死后出血的影响.方法 诱导制备2型糖尿病大鼠,糖尿病大鼠与正常血糖鼠均采用线栓法制备大脑中动脉局灶性脑缺血模型.应用墨汁灌注脑血管法观察脑内血管,2,3,5-三苯四氮唑（TTC）染色法检测梗死体积,免疫组织化学方法 检测VEGF与CD34的表达.结果 墨汁灌注脑血管后在糖尿病组可见细小血管明显增生.TTC染色见糖尿病组梗死局限在皮质下,成蚕豆样,正常血糖组梗死相对弥散,广泛累及皮质,且糖尿病组梗死体积[（80.07±11.21）mm3]明显小于正常血糖组[（98.91±14.86）mm3],差异具有统计学意义（t=2.48,P=0.0326）.糖尿病组可见明确的梗死后出血.免疫组织化学结果 显示VEGF与CD34的表达在糖尿病组明显高于正常血糖组,且差异均具有统计学意义.结论 糖尿病脑缺血性梗死后VEGF与CD34表达高于正常血糖组.糖尿病可明显诱导脑血管扭曲、重构及新生.这些病理性血管在脑缺血后可能会减小梗死体积但加重梗死后出血而影响预后.

Objective To study the function of vascular endothelial growth factor （VEGF） in type 2 diabetes model rats and its effect on focal cerebral ischemia induced by middle cerebral artel7 occlusion in these rats. Methods Focal cerebral ischemia was induced by middle cerebral artery occlusion for 6 hours in type 2 diabetes rats and normal control rats. Blood vessels morphology was examined by ink perfusion, infarct size was measured by TTC and expression of VEGF and CD34 were evaluated by immunohistochemistry staining. Results Ink perfusion revealed increased number of small vessels in type 2 diabetes rats. Infarct size was significantly smaller in type 2 diabetes rats （ （80. 07 -＋ 11.21 ）mm3 ） than that in normal controls （（98.91 -＋ 14. 86） mm3, t = 2. 48, P = 0. 0326）. There were more hemorrhage lesions in the ischemie hemisphere in type 2 diabetes rats when comparing with the controls. VEGF and CD34 showed significantly higher expression in type 2 diabetes rats than in normal controls. Conclusions High expression of VEGF and CD34 are found in type 2 diabetes rats after middle cerebral artery occlusion. There is cerebrolvascular remodeling in diabetes rats. While this diabetes-induced remodeling appears to prevent infarct expansion, the changes also increase the risk of hemorrhagic transformation. The latter may result in poor prognosis.