摘要
目的:糖尿病视网膜病变早期改变与视网膜毛细血管结构损伤有关。动态观察病程12周和24周糖尿病大鼠视网膜微血管超微结构的病理变化。方法:实验于2002-05/2003-08在锦州医学院中心实验室完成。选用30只2月龄雄性SD大鼠。实验组大鼠按60mg/kg尾静脉一次性注射链脲佐菌素溶液,注射后第2,7天采尾血测血糖,以后每2周测1次血糖、尿糖,将血糖浓度>16.7mmol/L,尿糖阳性的大鼠定为糖尿病模型。实验组造模成功15只,实验12,24周时分别为8,7只。对照组大鼠未造成糖尿病模型,只注射等容积缓冲液,实验12,24周时各5只。取大鼠视网膜组织,实验组和对照组大鼠饲养12,24周时视网膜微血管超微结构及视网膜毛细血管基底膜厚度的变化经透射电镜下观察。结果:实验组和对照组纳入结果分析大鼠分别为15和10只。①视网膜微血管超微结构:对照组大鼠视网膜微血管内皮细胞和周细胞内异染色质分布均匀,细胞器、细胞核形态正常,基底膜结构清楚,连续完整。实验组大鼠实验12周时视网膜微血管内皮细胞水肿,线粒体肿胀变性,核染色质边集。周细胞改变较内皮细胞重,基底膜增厚。24周时视网膜微血管内皮细胞肿胀、变形,管腔明显狭窄,甚至闭塞。周细胞内结构消失,仅残留少许细胞器,基底膜明显增厚。②糖尿病大鼠视网膜毛细血管基底膜厚度:实验组大鼠实验12,24周时明显对应时间的对照组[(245.5±11.9),(310.6±28.0)nm;(214.1±16.1),(238.3±13.2)nm,P<0.01]。随着病程进展,与12周时糖尿病组比较,24周时糖尿病组视网膜毛细血管基底膜进一步增厚(P<0.05)。对照组大鼠视网膜毛细血管基底膜厚度不随实验进行而变化。结论:当糖尿病视网膜病变早期即出现视网膜内皮细胞及周细胞的改变,且基底膜增厚,随着病程延长病变进一步加重。
AIM: The early changes of diabetic retinopathy are related with the injury of retinal capillary structure. This paper is to dynamically observe the pathologic changes of the retinal microvascular ultrastructure in diabetic rats at 12 weeks and 24 weeks. METHODS: The experiment was carried out in the central laboratory of Jinzhou Medical College from May 2002 to August 2003. Thirty male SD rats of 2 months old were used. Rats in the experimental group were injected with streptozotocin (60 mg/kg) via caudal veins all at once, blood sample was drawn from tail to detect blood glucose at the 2nd and 7th days after injection, and than the blood glucose and uric glucose were detected once every two weeks; Rats with blood concentration > 16.7 mmol/L and positive uric glucose were taken as diabetic models, and 15 rats in the experimental group were successfully made into diabetic models, there were 8 and 7 rats at 12 and 24 weeks respectively. Rats in the control group were not made into diabetic models, and only injected with buffer of the same volume, there were 5 rats at 12 and 24 weeks respectively. Their retinal microvascular ultrastructure were taken, the retinal microvascular ultrastructure and retinal capillary basement membrane thickness changes were observed under transmission electron microscope in the experimental group and control group at 12 and 24 weeks respectively. RESULTS: Fifteen rats in the experimental group and 10 rats in the control group were involved in the analysis of results. ① The retinal microvascular ultrastructure: In the control group, the heterochromatine distributed evenly in both retinal microvascular endothelium and pericyte, the shapes of organelle and nucleus were normal, the structure of basement membrane displayed clear and integrity. In the experimental group, there was edema of endothelium, swelling and degenerated mitochondrion, limited nuclear chromatin in retinal microvessel at 12 weeks; At 24 weeks, there was swelled and deformed endothelium in retinal microvessel, vascular lumen was obviously constricted and even blocked, inner structure of pericyte disappeared, only a bit of organell remained, and basement membrane was obviously thickened. ② The retinal capillary basement membrane thickness in diabetic rats: It was obviously thicker in the experimental group than in the control group both at 12 and 24 weeks [(245.5±11.9), (310.6±28.0) nm; (214.1±16.1), (238.3±13.2) nm, P < 0.01]; With the process of disease, compared with at 12 weeks, the retinal capillary basement membrane was further thickened at 24 weeks in the experimental group (P< 0.05); The retinal capillary basement membrane thickness was not changed with the experimental process in the control group. CONCLUSION: There are changes of retinal capillary endothelium and pericyte at the early period of diabetic retinopathy, and the capillary basement membrane is thickened, it is further aggravated with the process of disease.
出处
《中国临床康复》
CSCD
北大核心
2005年第23期126-127,共2页
Chinese Journal of Clinical Rehabilitation
