Loss of endothelium-dependent relaxation in abdominal aorta preserved in a co-storage system.

The potentially detrimental influence of parenchymal cells on endothelial function during preservation in UW solution was examined by co-storage of rat abdominal aortic rings with isolated liver cells. Cold storage of rings in UW solution alone for up to 96 h had no effect on the response to acetylcholine, though constriction was progressively lost. Co-storage of rings with liver cells resulted in no loss of sodium nitroprusside response, but the relaxation response to acetylcholine was reduced.

Prevention of contrast medium-induced renal vasospasm by phosphodiesterase inhibition.

Rationale And Objectives: This study investigated the involvement of cyclic 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 renal vasospasm.

Methods: Isometric contractions of rabbit renal artery rings were subjected to increasing concentrations of the ionic contrast medium sodium/meglumine diatrizoate (DIA) and the nonionic contrast media iopamidol (IOP) and iodixanol (IOD) and compared with a potassium chloride control. Subsequently increasing concentrations of the nonselective phosphodiesterase inhibitors theophylline and papaverine and the following selective phosphodiesterase inhibitors were applied: vinpocetine, trequinsin, zardaverine, rolipram, and dipyridamole (subtypes I-V) before restimulation of the arterial tissue with contrast medium.

Histamine release and contrast media-induced renal vasoconstriction.

Rationale And Objectives: The authors' purpose was to investigate the role of histamine release causing renal vasoconstriction induced by application of contrast media, an important element in contrast medium-induced nephrotoxicity.

Materials And Methods: Isometric contractions in rabbit segmental renal arteries stimulated with KCl and increasing concentrations of the ionic contrast medium diatrizoate and the nonionic agents iomeprol and iodixanol were studied both with and without increasing concentrations of the histamine H1 and H2 blockers diphenhydramine and cimetidine. Histamine concentrations after contrast medium application were determined.

Effect of contrast medium on corpus cavernosum smooth muscle.

Rationale And Objectives: Changes in contractility of corpus cavernosum (CC) smooth muscle caused by radio contrast medium may result in misinterpretations of cavernosography used diagnostically in erectile dysfunction.

Methods: The authors investigated the direct effect of various contrast media on rabbit CC smooth muscle tissue strips in an in vitro model by adding contrast medium to the tissue in a perfusion bath and recording the resulting contractions. Glucose addition was used as control.