Objective: The oxidative stress and renal vasoconstriction are considered to have an effect on the pathophysiology of contrast induced nephropathy. In this study, we aimed to evaluate the effects of contrast agents on serum creatinine, total antioxidant capacity and estimated glomerular filtration rate in patients undergoing coronary angiography with normal renal function.

Materials and Methods: Fourty-two patients undergoing coronary angiography were randomized to receive either non-ionic low-osmolar or iso-osmolar contrast agent. Serum total antioxidant capacity, serum creatinine levels were measured before and 6 hours after intravenous contrast agent administration. Estimated glomerular filtration rate was determined according to the Modification of Diet in Renal Disease formula. The patients were followed up for 3 to 9 months for a possible kidney injury.

Results: Serum total antioxidant capacity, estimated glomerular filtration rate values were significantly decreased and serum creatinine values were significantly increased in both of the study groups when the pre- and post-angiographic values were compared. No significant difference was demonstrated between the two groups regarding renal functions.

Conclusion: The early oxidative stress observed after administration of low doses of contrast media in patients with normal renal functions was not found to be the early sign for contrast induced nephropathy. Further studies are needed to assess the role of oxidative stress in the pathophysiology.