实验性糖尿病视网膜病变超微结构改变与 碱性成纤维细胞生长因子表达

目的探讨实验性糖尿病大鼠视网膜病变超微结构改变与碱性成纤维细胞生长因子( basic fibroblast growth factor, bFGF )表达的关系。方法用链脲佐菌素 (streptozotocin, STZ)建立糖尿病大鼠模型，随机分为正常对照组，糖尿病1、3、5个月组。分别行视网膜超微结构的透射电镜观察及视网膜石蜡切片上bFGF原位杂交、免疫组织化学检查。结果透射电镜观察：正常对照组大鼠视网膜血管未见异常，糖尿病1个月大鼠视网膜血管基底膜节段性增厚，内皮细胞肿胀，指状突明显，周细胞异染色质分布不均，可见肿胀的线粒体；3个月大鼠可见视网膜血管内皮细胞肿胀明显加重，管腔狭窄几乎接近闭塞；5个月大鼠视网膜血管基底膜明显厚薄不均，有些明显增厚，有些断裂甚至缺失。糖尿病大鼠视网膜bFGF原位杂交及免疫组织化学染色均从糖尿病3个月时开始有表达。糖尿病3个月时bFGF原位杂交的阳性率为 77.8%，免疫组织化学染色阳性率为 55.6%，糖尿病5个月时均增加到88.9 %。结论STZ大鼠视网膜超微结构改变在先，视网膜中bFGF的表达要晚于超微结构的改变。(中华眼底病杂志,2003,19:348-351)

Ultrastructural changes and expression of basic-fibroblast growth factor of diabetic retinopathy

Objective To investigate relationship between ultrastructural changes and expression of basic fibroblast growth factor of diabetic retinopathy in rats. Methods Diabetes was induced in rats with a single injection of streptozotocin (STZ) and divided into normal control group and 1-, 3- and 5-month diabetes group. The paraffin slide was observed by in-situ hybridization and immunohistochemistry, and retinal ultrastructure was examined by transmission electron microscopy. Results No change of retinal ultrastructure was found in the control group. Different degrees of ultrastructure lesion were found in 1-month diabetic rats with fragmental increase of thickness of basement membrane, swelling of endothelial cells and obvions finger-like processes in the capillary cavity, disconcentration of heterochromatin both in endothelium and pericyte, and swelling and degeneration of mitochondrion. The edema of endothelial cells of 3-month diabetic rats was more serious than that of 1-month ones, and the capillary cavity was nearly occluded. In 5-month diabetic rats, the basement membrane was unevenly thickened, or obviously split. The positive rate of in-situ hybridization in 3-month diabetic rats was 77.8% while the positive rate of immunohistochemical stain was 55.6%, which increased to 88.9% in 5-month diabetic rats. Conclusions The occurrence of the ultrastructural changes in STZ rats with diabetic retinopathy is earlier than that of the expression of bFGF.