急性不完全脑缺血大鼠心房特殊颗粒变化的形态学及形态计量学研究

THE STUDY OF MORPHOLOGY AND MORPHOMETRY OF THE ATRIAL SPECIFIC GRANULES IN RATS WITH ACUTE INCOMPLETE CEREBRAL ISCHEMIA

本实验应用形态计量学的方法研究了心房特殊颗粒的变化与脑缺血的关系。实验用中老年 Wistar大鼠 ,采取双侧颈总动脉夹闭 2 h后去夹再灌流的方法制作急性不完全性脑缺血模型。于再灌后 6h、2 4h、3 d及 7d,处死大鼠 ,在 10 0 s内取出右心耳 ,常规超薄切片及染色 ,电镜观察心房特殊颗粒的变化并进行形态计量学研究。结果显示 :脑缺血再灌后 6h,心房特殊颗粒几乎释放殆尽 ,2 4h及 3 d数量明显减少 ,颗粒变小 ;形态计量研究表明 ,缺血再灌组大鼠心房特殊颗粒的体积密度、面数密度、数密度及颗粒的平均直径 ,除 7d者外 ,其余均比假手术组有不同程度的减小 ( P<0 .0 1,P<0 .0 5 )。本实验结果表明 ,心房特殊颗粒内所含的心房肽参与早期脑缺血缺氧的病理生理过程 。

The relationship between the change of atrial specific granules(ASG) and cerebral ischemia was studied with the method of morphometry. The model of acute incomplete ischemia was made with middle aged Wistar rats by the method of reperfusion after 2 h of bilateral common carotid occlusion. The rats were sacrificed 6 h, 24 h, 3 d and 7 d respectively after reperfusion and the right atrial appendage was removed within 100 seconds. The material were ultra thin sectioned and stained to observe the change of the ASG with electron microscope, and morphometry study was performed. The result showed that ASG were almost all released 6 h after reperfusion, the number and diameter of the ASG were decreased obviously after 24 h and 3 d. The morphometry results indicated that the volume density, numerical density of area, numerical density and average diameter of the ASG were reduced differently in degrees(P<0.01, P<0.05), except those that were sacrificed after 7 d. The experiment showed that the atrial natriuretic polypeptide(ANP) within the ASG was involved in the process of the early stage cerebral ischemia pathophysiology, and ANP made positive contributions in preventing the damage of the brain cells. (Figures A～H on plate 12)