大鼠急性脑缺血再灌注后血管源性水肿MRI与脑组织VEGF表达

MRI manifestations of vasogenic brain edema in acute ischemia reperfusion rats and VEGF expression of ischemic brain tissue

目的 :探讨缺血再灌注后血管源性水肿 (VBE)的MRI表现及其与脑组织血管内皮细胞生长因子 (VEGF)表达的相关性。方法 :线栓法制作缺血再灌注后VBE模型 ,MRI动态观察VBE征象 ,免疫组化染色观察血管内皮细胞生长因子 (VEGF)表达。结果 :VBEMRI表现为缺血脑组织体积增加T2 WI信号增高 ,在缺血后 1～ 2d达到高峰。 12h～ 3d免疫组化染色见缺血区神经细胞、血管内皮细胞及胶质细胞阳性染色 ,血管内皮细胞染色强度在 12h～ 3d呈递增趋势 ,与VBEMRI征象改变呈正相关 (r =0 .82 0～ 0 .994)。结论 :MRI可动态观察脑缺血后VBE ,缺血再灌注后脑组织VEGF表达与VBEMRI征象的进展密切相关。

Objective:To investigate the correlation of MRI findings of vasogenic brain edema (VBE) after ischemia reperfusion of rats and its VEGF expression of brain tissue.Methods:The thread occlusion of right middle cerebral artery (MCA) was made to set up VBE models in rats.Dynamic evaluation with MRI was performed to evaluate VBE.The specimen were analyzed at various time immunohistochemisically after reperfusion.Results:The signs of VBE were most prominent at 1～2d after ischemia,these signs included volume enlargement and increase of signal intensity on T 2WI.On immunohistochemistry examintaion, positive plasma brown stain in neurocytes,endothelium and gliocytes in ischemic brain tissue were detected.And the stain was intensified gradually from 12h to 72h.The score of immunohistochemistry positive stain of specimen correlated with MRI signs of VBE ( r =0.820～0.994).Conclusion:VBE could be evaluated dynamically with MRI.VEGF expression of brain tissue was positive correlated with MRI signs of VBE in ischemia reperfusion model of rats.