糖尿病大鼠视网膜视细胞超微结构病理变化的研究

目的:探讨糖尿病大鼠视网膜病变（diabetic retinopathy.DR.简称糖网病）,早期视细胞（视感受器）的超微结构病变,为糖网病光感受器功能障碍提供形态学依据。方法:选择清洁级SD大鼠随机分成正常对照组（CON）、糖尿病1月（DM1）、3月（DM3）和6月（DM6）。按60mg/kg腹腔内注射链脉佐菌素（STZ）诱导大鼠糖尿病,每组12只,取大鼠视网膜透射电镜观察。处死前每月测血糖和眼底镜检查1次。结果:病程1个月:视杆、视锥细胞的外节膜盘模糊不清,膜盘间隙略有扩大,椭圆体内中心粒和纤毛仍清晰可见,线粒体规则的排列在周围。病程3个月,视细胞外节膜盘间隙明显扩大,纵横交错,排列紊乱,并发生局灶性断裂,椭圆体内有部分线粒体肿胀、脱嵴。毛细血管扩张,神经纤维中心微管也有水肿。病程6个月:视细胞外节内膜盘断裂溃变,颜色淡,并出现许多泡沫状结构,椭圆体内的线粒体变小,排列不规则,有的脱嵴、水肿,毛细血管已有部分由扩张转为狭窄。结论:糖尿病早期毛细血管由局部扩张转为狭窄,视网膜因缺血、缺氧的加重导致视细胞超微结构的病理改变,并随病程的进展而加重。

Study on ultrastructural pathological change of visual cell in diabetic rats and its clinical significance

Objective: To investigate ultrastructural pathological change of photoreceptors in early diabetic retinopathy (DR) in rats,and to furnish the morphological evidence of visual dysfunction in DR. Methods; The SD rats were chosen and divided at random into normal group (CON) .diabetic groups 1 month (DM1) ,3 month (DM3) and 6 month (DM6) respectively (n = 12). Diabetic rat was induced by injected streptozotocin (60 rug/kg) into abdominal cavity. The blood sugar was tested the foundus was examined once a month before put to death. Then the retina were prepared into the ul-trathin sections and were observed by transmission electron microscope. Results; With blood sugar rising the condition of illnese worsened, the membrane disc of outer segment of visual cell had pathological change from indistinct to enlarged, the interspace of disc were enlarged,and arranged in confusion and crisscross,even broken locally, broken and festered in the middle. The capillaries were from dilated to narrowed. Conclusion;The ultrastructure pathological change of photoreceptor in retina and visual dysfunction are caused by the ischemia and hypoxia.