Diabetes-induced biochemical changes in rat lens: attenuation of cataractogenesis by pyruvate.

Summary Aim: Studies have been conducted to determine the effect of pyruvate administration on the biochemistry of rat lens and the status of its transparency as affected by diabetic conditions. Methods: Sprague-Dawley rats were rendered diabetic by intravenous (i.v.) injection of streptozotocin (55 mg/kg body weight (b.w.)) and treated with sodium pyruvate (2%) in drinking water. The levels of glucose, fructose, sorbitol, ATP, GSH, MDA as well as glycated proteins in the lenses were determined at various intervals after the onset of diabetes and the values compared with untreated diabetic controls. The progress of cataract formation and associated histological changes in the tissue were also monitored. Results: Studies show that the pyruvate treatment decreased the extent of several biochemical changes known to be associated with cataract formation, such as the elevation in the levels of glycated proteins, sorbitol, lipid peroxidation (MDA) and inhibition of the cation pump. The progress of cataract was also significantly delayed. Conclusion: Exogenous administration of this compound hence was found to exert an overall protective effect against cataract formation induced by the diabetic conditions.