脑缺血再灌注高血压大鼠神经肽Y和超微结构变化

目的观察易卒中型肾血管性高血压大鼠(RHRSP)脑缺血再灌注过程中不同时间点脑组织神经肽Y(NPY)表达和细胞超微结构的动态变化。方法制作RHRSP模型,用线栓法制作左侧大脑中动脉闭塞模型,用放射免疫法、干湿重法、图像分析和透射电镜等技术检测脑缺血6h再灌注6、72、168h时脑组织NPY、水含量、梗死面积百分率和超微结构的动态变化。结果再灌注组脑组织NPY和含水量均明显高于对照组和假手术组(P<0·01),72h达高峰;脑梗死面积百分率显著增高,168h时开始下降,但仍高于对照组和假手术组(P<0·01)。再灌注不同时间点分别出现不同程度的神经元和血管壁超微结构损害。结论NPY可能参与了RHRSP缺血再灌注脑损伤的病理学过程。

The Changes of Neuropeptide Y and Ultrastructure During Cerebral Ischemic Reperfusion in Hypertensive Rats

Objective: To observe the dynamic changes of neuropeptide Y (NPY) and ultrastructure in brain tissues in stroke-prone renovascular hypertensive rats (RHRSP) at the different time points after reperfusion. Methods : RHRSP model was established, and left middle cerebral artery occlusion was induced by the suture method. NPY, water content, percentage of infarcted area, and dynamic changes of ultrastructure in brain tissues after 6 hours of cerebral ischemia and followed by 6, 72 and 168 hours of reperfusion were detected with radioimmunity, dry and wet weight method, image analysis, and transmission electron microscope. Results: The levels of NPY in the reperfusion groups was significantly higher than that of the control group and the sham-operated group (P<0.01). NPY level reached to the peak after 72 hours of reperfusion, the percentage of the infarcted area is significantly high, then it decreased after 168 hours of reperfusion, but it is still higher than that of the control group and the sham-operated group ( P< 0.01). Different degrees of ultrastructure injuries were showed in neurons and vascular walls at the different time points after reperfusion. Conclusions: NPY may participate in the pathologic process of RHRSP in acute cerebral ischemic reperfusion injury.