[Effect of pyruvate on polyol pathway and lens epithelium apoptosis in diabetic rats]
March 16th, 2008 | by admin |[Effect of pyruvate on polyol pathway and lens epithelium apoptosis in diabetic rats]
OBJECTIVE: To investigate the effect of polyol pathway on the lens epithelium apoptosis and caspase-3 activity and its reversal by pyruvate in diabetic rats. METHODS: Two hundred and twenty Wistar rats were divided into 3 groups: control group (60 rats), experiment group (80 rats) and treatment group (80 rats). After streptozotocin (STZ) induced cataract, the treatment group received 2% pyruvate in the diet and drinking. Lens opacification was detected by microscope every 2 weeks. Amounts of glucose and sorbitol in the lens were quantified by high-performance liquid chromatography 4, 8 and 12 weeks after the treatment. The percentage of lens epithelium undergoing apoptosis was measured by Annexin V-PI staining. The activity of caspase-3 was analyzed by Western-blot. RESULTS: Present study showed that there was significant increase of glucose and sorbitol in the lens in the experiment group, the apoptosis rate and caspase-3 activity of lens epithelium were also gradually increased. Pyruvate treatment decreased the levels of sorbitol, glucose, lens epithelium apoptosis and caspase-3 activity. The progress of cataract was also significantly delayed. CONCLUSIONS: Activation of polyol pathway, possibly through regulation of the activity of caspase-3, can induce apoptosis of the lens epithelium. Pyruvate ingested orally can effectively inhibit diabetic cataractogenesis in rats through inhibit polyol pathway.
Qi YX, Yu HL, Meng DX, Zhang D, Zhang JS.
Department of Ophthalmology, the Fourth Affiliated Hospital, China Medical University, Shenyang 110001, China.