RATIONALE AND OBJECTIVES. The authors compared the physiologic and nephrotoxic effects of the magnetic resonance imaging contrast medium gadopentetate with two conventional radiographic contrast media.
METHODS. Rabbits were injected intravenously with one of the following solutions: 1) gadopentetate (0.1 M); 2) iohexol (300 mg I/mL); 3) metrizoate (300 mg I/mL); and 4) NaCI (0.9%). Blood samples were taken before and 5, 15, 45, 90, and 180 minutes after injection of the solutions and were analyzed for creatinine, aldosterone, and contrast media levels. Urine was sampled before and 1, 2.5, and 5 hours after injection of the solutions, and creatinine, leucine amino peptidase (LAP), alkaline phosphatase (ALP), gamma glutaryl transferase (GGT), and N-acetyl β-D-glucosaminidase (NAG) activities were quantified.
RESULTS. Contrast media clearance was similar for gadopentetate, iohexol, and metrizoate. Plasma aldosterone was significantly higher in the two groups injected with iodinated contrast agents compared with the gadopentetate and saline groups in the 3-hour samples. During the 5 hours after injection, the excretion of brushborder enzymes LAP, ALP, and TGT was significantly higher for all contrast media compared with pre-contrast values and 0.9% NaCI controls. NAG, a lysosomal enzyme from tubular cells, showed a significant increase compared with pre-contrast values for all contrast media.
CONCLUSIONS. Intravenous injection of gadopentetate in rabbits showed nephrotoxicity of the same order as that of conventional iodinated contrast media.
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