Evidence of oxidative stress in the renal cortex of diabetic rats: favourable effect of vitamin E.
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.
Jacheć
W
W
Department of Biochemistry, Silesian Medical Academy, Zabrze, Poland.
Tomasik
A
A
Tarnawski
R
R
Chwalińska
E
E
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology / Q000378:metabolism*; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D007672:Kidney Cortex / Q000201:enzymology / Q000378:metabolism*; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress; D051381:Rats; D013311:Streptozocin; D013482:Superoxide Dismutase / Q000378:metabolism; D014810:Vitamin E / Q000008:administration & dosage*
D001786:Blood Glucose; D014810:Vitamin E; D008315:Malondialdehyde; D013311:Streptozocin; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005982:Glutathione Transferase