Pathogenesis of diabetic cataract in rats induced by streptozotocin

    DING Zhengª²Hua, YAN Hong, GUO Yong, HA Wenª²Jing, WANG Jianª²Wei

    Department of Opthalmology, Tangdu Hospital, Fourth Military Medical University, Xi¬ðan 710038, China

    ¡¾Abstract¡¿ AIM: To set up the diabetic cataract model and to explore the mechanism of diabetic cataract in rats induced by streptozotocin (STZ). METHODS: Diabetic rats were made by a single intaperitoneal injection of STZ (65 mg/kg). The changes of plasma glucose, urine glucose and body weight were monitored and the progression of lens opacification was recorded using the slit lamp every week. At 13th week, the levels of glutathione reductase (GR), catalase (CAT), glutathione (GSH) and glycated protein in lens were determined. RESULTS: About 70% (14/20) of the rats responded to the streptozotocin injection and the diabetic symptoms were observed in these rats. Only one rats (1/14) was rejected for the decrease of plasma glucose (<14 mmol/L). Lens opacification progressed in a biphasic manner in the diabetic rats, an initial slow progression during the first 8 weeks of diabetes followed by a steep increased lens opacification in the next 5 weeks. There was statistically significant difference between the diabetic group and the normal group in the level of CAT (nkat, 479.3¡À339.0 vs 1002.0¡À467.6), GSH (mg/g, 55.2¡À32.6 vs 102.7¡À39.1) and glycated protein (mmol glycation per mol protein, 5.4¡À0.5 vs 4.17¡À0.4) (P<0.05). CONCLUSION:The diabetic model induced by a single intaperiª²toneal injection of streptozotocin was reliable for study in diabetic cataract. Lens protein glycation and oxidative damage may play some significantcant roles in the development of diabetic cataract. ......