Dietary hypercholesterolemia aggravates contrast media-induced nephropathy.
BACKGROUND
Contrast media administration can result in severe nephrotoxicity under pathological conditions such as diabetic nephropathy, congestive heart failure, dehydration, et al. The purpose of this study was to evaluate the effects of dietary hypercholesterolemia on contrast media-induced changes in renal function, blood flow, and histopathology.


METHODS
Rats were fed either on a normal rodent diet (group N) or a high-cholesterol supplemented diet (group H; 4% cholesterol and 1% cholic acid) for 8 weeks. Half of the animals (n = 6) from each diet group were then given a tail vein injection of 60% diatrizoate (6 ml/kg; group NC and group HC) and the other half were administered saline. Total serum cholesterol, triglyceride, serum creatinine, creatinine clearance rate, fractional excretion of sodium and potassium, and cortical nitric oxide production were determined one day following contrast media administration. Renal blood flow was determined by color Doppler flow imaging and pulsed-mode Doppler. Renal histopathology was observed by light microscopy.


RESULTS
Total serum cholesterol and resistance indices of renal blood vessels increased significantly, while creatinine clearance rate and production of nitric oxide in the renal cortex decreased markedly in group HC and group H when compared to group N and group NC. The creatinine clearance rate decreased significantly in group HC compared to group H. Serum creatinine levels and fractional excretion of sodium and potassium in group HC were significantly higher than those in the other three groups. Severe tubular degeneration and necrosis, protein cast accumulation, and medullary congestion were found in group HC.


CONCLUSIONS
Hypercholesterolemia is a risk factor for contrast media-induced nephropathy. Hypercholesterolemia aggravates contrast media-induced nephrotoxicity through the reduced production of nitric oxide.
Yang
Ding-Wei
DW
Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan 430060, China.
Jia
Ru-Han
RH
Yang
Ding-Ping
DP
Ding
Guo-Hua
GH
Huang
Cong-Xin
CX
D000818:Animals; D002791:Cholesterol, Dietary / Q000633:toxicity*; D003287:Contrast Media / Q000633:toxicity*; D007674:Kidney Diseases / Q000139:chemically induced*; D008055:Lipids / Q000097:blood; D008297:Male; D009569:Nitric Oxide / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D012079:Renal Circulation
D002791:Cholesterol, Dietary; D003287:Contrast Media; D008055:Lipids; D009569:Nitric Oxide