Activity of glutathione-dependent enzymes in long term diabetes. II. Glutathione contents and activity of glutathione-dependent enzymes: S-transferase and peroxidase in the kidney cytosol of alloxan induced diabetic rats.

In the kidney of diabetic rats the elevated GSH concentration was accompanied with the 25% increase of cytosolic Se-dependent glutathione peroxidase (Se-GSHPx) activity. The activity of cytosol glutathione S-transferase (GST) was decreased to 55% of the control with p-nitrobenzyl chloride, and was unchanged with 1-chloro-2,4-dinitrobenzene, and ethacrynic acid. The activity of GST with cumene hydroperoxide (a good substrate for determination the activity of non Se-GSHPx) in diabetic animals stay unchanged too. Insulin treatment of diabetic rats restores the normal glycemia and the body weight, strongly reduces glucosuria and reverses the morphological changes observed in the kidney. The activity of GST and cytosol Se-GSHPx, as well as GSH content, returned to a normal values after insulin treatment, while the activity of non Se-GSHPx was reduced of about 50% in relation to the control values.