Effects of Short- and Long-Term Hypercholesterolemia on Contrast-Induced Acute Kidney Injury

<i>Background:</i> Whether hypercholesterolemia is a risk factor for contrast-induced acute kidney injury (CI-AKI) remains unclear. In the present study, the effects of short- and long-term dietary hypercholesterolemia on contrast media-induced nephrotoxicity were evaluated. <i>Methods:</i> Rats were fed either a normal rodent diet (N) or high-cholesterol diet (H). At the end of 2 and 8 weeks, 8 rats from each diet group were given a tail vein injection of either iohexol (group NC and group HC) or vehicle (group N and group H). Blood lipids, renal function and renal hemodynamics were evaluated 1 day after contrast media administration. Renal and urinary prostaglandin E₂ (PGE₂) and thromboxane B₂ (TXB₂) were detected by radioimmunoassay. Renal nitric oxide and malondialdehyde (MDA) were measured by the Griess reaction and thiobarbituric acid method, respectively.<i> Results:</i> Contrast media administration increased serum creatinine levels and induced severe renal tubular necrosis in rats fed the high-cholesterol diet for 8 weeks but not in rats fed the normal diet or high-cholesterol diet for 2 weeks. The renal and urinary PGE₂ and TXB₂ levels increased significantly in rats in group H and group HC at the end of 8 weeks. Renal nitric oxide production decreased, and MDA levels increased markedly in group HC and group H at the end of 8 weeks. <i>Conclusions:</i> We conclude that long-term hypercholesterolemia appeared to be a risk factor for CI-AKI, which might be associated with disorders in intrarenal prostaglandins and abnormalities in renal nitric oxide system induced by lipid peroxidation.