糖尿病大鼠视网膜毛细血管细胞凋亡——TUNEL法研究

目的： 确定早期糖尿病视网膜病变 （糖网病） 大鼠视网膜毛细血管细胞凋亡并观察凋亡特征。方法： 选成年ｗ ｉｓｔａｒ大鼠４０ 只， 随机分成正常对照（ Ｃ Ｏ Ｎ）、糖尿病１ 月 （ Ｄ Ｍ１）、３ 月 （ Ｄ Ｍ３） 及６ 月 （ Ｄ Ｍ ６） 组。采用链脲佐菌素腹腔内注射诱发大鼠糖尿病。取各组大鼠视网膜制备血管铺片， Ｔ Ｕ Ｎ Ｅ Ｌ法标记， 光镜观察。结果： Ｔ Ｕ Ｎ Ｅ Ｌ法标记的阳性周细胞核出现于 Ｄ Ｍ３ 和 Ｄ Ｍ６ 组，而内皮细胞见于 Ｄ Ｍ ６ 组。 Ｃ Ｏ Ｎ 和 Ｄ Ｍ１ 组未见阳性反应细胞。被标记的周细胞核小而圆， 位于毛细血管侧面， 稍突出于血管壁。而内皮细胞核大而呈现椭圆形， 位于毛细血管中央， 与血管平行， 阳性反应细胞染色质分布不均， 表现为环形核、新月形核等典型的凋亡细胞特征。结论： 早期糖网病大鼠视网膜毛细血管周细胞丧失的性质为细胞凋亡， 内皮细胞亦存在凋亡。

APOPTOSIS OF RETINAL CAPILLARY CELLS IN DIABETIC RATS A STUDY BY TUNEL METHOD

Objective:To determine apoptosis of retinal capillary cells in early diabetic retinopathy(DR)and observe apoptotic features Methods:Adult wistar rats were randomly divided into four groups of normal contrast(CON),one month(DM1),three month(DM3),and six months (DM6)of diabetes mellitus Diabetic rats were induced by streptozotocin intraperitoneally Retinal preparations of blood vessels of every group rats were labelled by TUNEL method and observed under light microscope Results:Positive pericyte nuclei labeled by TUNEL methods emerged in DM3 and DM6,but positive endothelial cell nuclei only in DM6 No positive reaction was seen in CON and DM1 Labelled pericyte nuclei was round and small,lying in the side of capillary walls protruding a bit But endothelial cell nuclei labelled by TUNEL method were situated in the middle of capillary walls shaped oval and parallel to the capillaries Chromatin of positive nuclei were distributed unequally showing apoptotic characteristics of ring like and crescent nuclei Conclusion:The nature of pericyte dropout in early DR of rats was apoptosis and apoptosis also existed in endothelial cells