大鼠糖尿病视网膜病变模型建立及超微结构观察

目的建立链脲佐菌素（STZ）诱导的糖尿病大鼠视网膜病变模型并观察视网膜微血管及视细胞的超微结构,评价其应用价值。方法选择健康成年雄性清洁型SD大鼠60只,随机分为正常对照组、糖尿病1个月组、糖尿病3个月组、糖尿病6个月组。大鼠一次性腹腔注射STZ诱发糖尿病模型,观察各组大鼠的生理指标,并对糖尿病模型大鼠进行视网膜组织学检查及微血管超微结构观察。结果STZ腹腔注射糖尿病大鼠成模率为100%,死亡率为4.4%。早期糖尿病大鼠视网膜厚度变薄,视细胞数目随月龄增加而逐渐减少。毛细血管内皮细胞水肿,线粒体肿胀。毛细血管基底膜增厚,管腔狭窄,甚至闭塞。视细胞外节膜盘间隙扩大,排列紊乱。内节线粒体水肿,排列不规则。结论STZ诱导的糖尿病大鼠视网膜病变模型成模率高、方法可靠;糖尿病大鼠视网膜病变在发生发展、病理变化等方面与人类糖尿病视网膜病变具有相同或相似的特征,应用此模型可对糖尿病视网膜病变的病理学、发病机制和药物治疗等多方面进行研究。

ESTABLISHMENT OF DIABETIC RETINOPATHY IN RAT AND OBSERVATION OF THE RETINAL UNTRASTRUCTURAL CHANGES

ObjectiveTo establish a model of early diabetic retinopathy in rat and study the retinal ultrastructural changes.MethodsSixty adult male SD rats were divided into four groups: normal control group(CON),diabetes for 1 month(DM1),diabetes for 3 months(DM3),diabetes for 6 months(DM6).The diabetic rat model was induced by intra-peritoneal injection of streptozotocin(STZ).Physiological factors of the rats were examined and the retinal pathology and ultrastructural changes studied.ResultsDiabetes was induced in all of the rats.The mortality of the rats was 4.4%.Ultrastructural study showed that the retina became thinner in early diabetic rats.The number of visual cells became decreased along with duration of the experiment.The capillary endothelial cells and mitochondria became swollen.The basement membrane of capillaries became thicker.There was narrowing and even occlusion of the capillary lumen.The membrane disc space of visual cell outer segment was enlarged and arranged disorderly.The mitochondria of inner segments was swollen and arranged irregularly.ConclusionThe diabetic retinopathy rat model induced by intra-peritoneal injection of streptozotocin(STZ) shows similarities in the development of retinal lesions and ultrastructural changes to human diabetic retinopathy.With its easy manipulation and higher succes rate,the model can be potentially used for pathological,etiologic and therapeutic study of retinopathy.