Contrast media injection in the rat after multiple renal insults. No evidence of additional nephrotoxicity

A new animal model for testing renal tolerance of contrast agents

RATIONALE AND OBJECTIVES

To develop a new animal model for the evaluation of the renal tolerance of contrast agent and its application to diatrizoate and iotrolan injections in comparison to saline and mannitol solution.

MATERIALS AND METHODS

The nephrotoxic potential of intravenously injected contrast agents in Beagle dogs was determined from the effects on the pharmacokinetics of creatinine injected immediately after these agents in comparison with the kinetics of creatinine injected alone. The kinetic parameters evaluated included plasma half-life, volume of distribution, and clearance. In a series of studies, the experimental conditions were optimized in terms of creatinine dose and the effects of diatrizoate, iotrolan, saline, and mannitol solution on the pharmacokinetic parameters of creatinine were determined.

RESULTS

Bolus injection of creatinine into dogs followed a dose-linear pharmacokinetic behavior with a terminal half-life of 90 minutes (10 mg/kg) and 108 minutes (20 mg/kg), respectively, and a clearance of 5 mL/min/kg. Injection of diatrizoate decreased the clearance and the half-life of creatinine significantly. A mannitol solution with the same osmolality as diatrizoate showed the same effect whereas physiological saline did not affect pharmacokinetic parameters of creatinine. The isotonic iotrolan was intermediate between saline and diatrizoate in its effects on creatinine clearance.

CONCLUSION

The effect of contrast agents on pharmacokinetic parameters of creatinine injected immediately after the administration of the agents in dogs might be a useful model for the evaluation of renal tolerance. In a cross-over study, iotrolan was not statistically separable from diatrizoate.

Use of near-infrared reflection spectroscopy to study the effects of X-ray contrast media on renal tolerance in rats: effects of a prostacyclin analogue and of phosphodiesterase inhibitors

RATIONALE AND OBJECTIVES

Use of near-infrared reflection spectroscopy (NIR-RS) as a new model to assess renal tolerance of contrast agents and determination of the effects of a prostacyclin analogue and of two phosphodiesterase inhibitors on renal tolerance.

MATERIALS AND METHODS

NIR-RS was used to measure total hemoglobin, oxygenated hemoglobin and tissue oxygen saturation in the renal cortex of rats and the effect of diatrizoate, iopromide and iotrolan injected at 1 g iodine/kg alone or together with the prostacyclin derivative, iloprost, or the phosphodiesterase inhibitors, rolipram and mesopram, on these parameters.

RESULTS

Injection of the contrast media alone resulted in a 10% to 35% depression of total hemoglobin, oxygenated hemoglobin, and tissue oxygen saturation approximately 40 to 100 seconds after administration, whereas saline showed no effect and mannitol solution only a minor effect. Coadministration of iloprost or pretreatment with the phosphodiesterase inhibitors, rolipram or mesopram, significantly attenuated the contrast media-induced effects.

CONCLUSION

NIR-RS might be useful for the determination of contrast media-induced side effects. Stable prostacyclin analogues or phosphodiesterase inhibitors have the potential to mitigate these side effects.