PREVENTION OF CONTRAST MEDIUM-INDUCED RENAL VASOSPASM BY PHOSPHODIESTERASE INHIBITION

RATIONALE AND OBJECTIVES. This study investigated the involvement of c yclic adenosine monophosphate (cAMP) in contrast medium-induced renal vasomotor effects and the efficacy of selective phosphodiesterase (PDE ) inhibitors influencing cAMP in preventing contrast medium-induced re nal vasospasm, METHODS. Isometric contractions of rabbit renal artery rings were subjected to increasing concentrations of the ionic contras t medium sodium/meglumine diatrizoate (DIA) and the nonionic contrast media iopamidol (IOP) and iodixanol (IOD) and compared with a potassiu m chloride control, Subsequently increasing concentrations of the nons elective phosphodiesterase inhibitors theophylline and papaverine and the following selective phosphodiesterase inhibitors mere applied: vin pocetine, trequinsin, zardaverine, rolipram, and dipyridamole (subtype s I-V) before restimulation of the arterial tissue with contrast mediu m, RESULTS. Diatrizoate, iopamidol, and iodixanol induced contractions up to 30%, 15%, and 3.5% of the potassium chloride control, respectiv ely, All phosphodiesterase inhibitors markedly inhibited the contrast medium-induced contractions in a dose-dependent manner. The selective phosphodiesterase inhibitors rolipram and trequinsin attenuated these contractions significantly more (92% and 94%) than did zardaverine, di pyridamole, and vinpocetine, with an inhibitory potency of 37%, 41%, a nd 62%, respectively. CONCLUSIONs. Nonionic contrast media induced ren al vasoconstriction less potently than ionic contrast media. Significa nt differences in the ability to prevent contrast medium-induced vasoc onstriction were observed among the various phosphodiesterase subtypes studied. selective phosphodiesterase inhibition with inhibitor subtyp es II and IV showed the most promising results in specifically prevent ing contrast medium-induced renal vasospasm.