Effect of Pyruvate on Polyol Pathway and Lens Epithelial Cells Apoptosis in Diabetic Rats

A poptosis of lens epithelial cells (LECs) is considered as pathogenesis of several types of cataract formation1]. Some studies have shown that apoptosis of lens epithelial cells plays an important role in the development of diabetic cataract2]. Recently, it has been re- ported that apoptosis of lens epithelial cells isinduced when lens epithelial cells are cultured in mediumcontaininghigh glucose3]. In the pre- sent study, rats were used to analyse apoptosis of lens epithelial cells in th…

Effect of Pyruvate on Polyol Pathway and Lens Epithelial Cells Apoptosis in Diabetic Rats

PURPOSE: To investigate the effect of polyol pathway on lens epithelial cells apoptosis and the activity of caspase-3 and its reversal by pyruvate in diabetic rats. METHODS: 220 Wister rats were divided into 3 groups: control group, model group and treatment group. After streptozotocin (STZ) induced cataract, the treatment group received 2% pyruvate in the diet and drinking. The opacification of lens was detected by microscope every 2 weeks. On 4W, 8W and 12W of the experiment, glucose and sorbitol in the lens were quantified by high-performance liquid chromatography. The percentage of lens epithelial cells undergoing apoptosis was measured by Annexin V/PI staining. The activity of caspase-3 was analyzed by Western-blot. RESULTS: Studies show that there was significant increase of glucose, sorbitol in lens of model group, the apoptosis rate and caspase-3 activity of lens epithelial cells were also gradually increase. Pyruvate treatment decreased the levels of sorbitol, glucose, lens epithelial cells apoptosis and caspase-3 activity. The progress of cataract was also significantly delayed. CONCLUSIONS: Polyol pathway, possibly through regulation of the activity of caspase-3, can induce apoptosis of lens epithelial cell. Pyruvate ingested orally can effective inhibit diabetic cataractogenesis in rats through inhibit polyol pathway.