Oxidant stress due to non ionic low osmolar contrast medium in rat kidney.

Background & objectives: Contrast media may cause contrast-induced nephropathy (CIN) in risk group. This study was taken up to establish possible effects of non ionic low osmolar contrast medium administration on oxidant/antioxidant status and nitric oxide (NO) levels in rat kidney tissues. Methods: Fourteen female, 14 wk old Wistar-albino rats were divided into 2 groups of 7 rats each (control and contrast groups). Non ionic low osmolar contrast medium was administered iv to the animals in the contrast group. The day after, animals were sacrificed and malondialdehyde (MDA) and NO levels and activities of antioxidant [superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT)] and oxidant [xanthine oxidase (XO)] enzymes were measured in kidney tissues. Serum creatinine levels were measured to evaluate kidney functions. Results: Contrast medium administration caused an increase in MDA levels and a decrease in NO levels in kidney tissues. Interpretation & conclusions: The results suggest that non ionic low osmolar contrast medium administration leads to accelerated oxidant reactions and decreased NO level in rat kidney tissues. Further studies need to be done to assess the role of these changes in CIN.

Reduced antioxidant potential & sensitivity to oxidation in plasma low density lipoprotein fraction in type 2 diabetes mellitus patients.

BACKGROUND & OBJECTIVES: The aim of this study was to investigate LDL oxidation in the ethiopathogenesis of diabetes mellitus. Diabetes mellitus a disease caused due to severe insulin dysfunction, is associated with lipid and protein metabolic disorders. METHODS: A total of 90 type 2 diabetes patients were grouped according to their glycoted haemoglobin (HbA1c) values as regulated (<5.7%), poorly regulated (5.7 - 7.7%) and unregulated (>7.7%). Further, a healthy control group of 37 individuals was included for comparison in terms of sensitivity of low density lipoprotein (LDL) to oxidation and measurements of antioxidant potential (AOP). A heparin - citrate precipitation method was used to obtain LDL from the serum samples of patients and control groups. The LDL fractions were exposed to oxidation with CuSO4 and sensitivity to oxidation was evaluated. Ten patients each from regulated and unregulated groups, and 10 healthy controls were examined for antioxidant potential. RESULTS: The sensitivity of LDL fraction to oxidation was significantly lower in all diabetic groups compared to the control group. AOP was significantly decreased in unregulated diabetic group compared to the control group. INTERPRETATION & CONCLUSION: We hypothesize that oxidant stress increases in diabetes mellitus and oxidant defense systems weaken during the chronic course of the illness. Due to decreased antioxidant potential, that probably shortens the LDL oxidation lag phase, the sensitivity to oxidation appears to be lower in diabetes mellitus patients.