Evidence of oxidative stress in the renal cortex of diabetic rats: favourable effect of vitamin E

Scand J Clin Lab Invest. 2002;62(1):81-8. doi: 10.1080/003655102753517244.


The aim of this study was to determine whether there are any disturbances of red/ox balance in the renal cortex of rats during the course of experimental diabetes. In the renal cortex of rats with streptozotocin-induced diabetes, the activity of superoxide dismutase (SOD) isoenzymes, glutathione peroxidase (GSH-Pox). glutathione S-transferase (GST) and glutathione reductase (GSH-RED) was measured in the 5th, 10th and 15th weeks of diabetes. Free radical cell damage was assessed on the basis of malonyldialdehyde (MDA) concentration. The influence of lipophilic antioxidant vitamin E on these analytes was also studied. An increase in MDA concentration in the 10th and 15th weeks of diabetes correlated significantly with plasma glucose concentration (r=0.47; p<0.001). Moreover, MDA concentration was influenced by time (+); p<0.001, diabetes (+); p<0.001, vitamin E (-) p<0.001 (ANOVA). Plasma creatinine concentration in rats was elevated by diabetes (p<0.001), whereas vitamin E decreased the concentration (p<0.05). Vitamin E lowered the activity of GSHPox (p<0.001) and GST (p<0.01) (ANOVA). Our results indicate that during experimental diabetes, disturbances of red/ox balance lead to disturbance in renal function manifested as increased creatinine blood concentration. We suggest that oral supplementation of vitamin E protects the renal cortex of rats during experimental diabetes.

MeSH terms

  • Animals
  • Blood Glucose / analysis
  • Diabetes Mellitus, Experimental / enzymology
  • Diabetes Mellitus, Experimental / metabolism*
  • Glutathione Peroxidase / metabolism
  • Glutathione Reductase / metabolism
  • Glutathione Transferase / metabolism
  • Kidney Cortex / enzymology
  • Kidney Cortex / metabolism*
  • Malondialdehyde / metabolism
  • Oxidative Stress*
  • Rats
  • Streptozocin
  • Superoxide Dismutase / metabolism
  • Vitamin E / administration & dosage*


  • Blood Glucose
  • Vitamin E
  • Malondialdehyde
  • Streptozocin
  • Glutathione Peroxidase
  • Superoxide Dismutase
  • Glutathione Reductase
  • Glutathione Transferase