Effect of contrast medium on corpus cavernosum smooth muscle.
OBJECTIVE
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.


RESULTS
Application of high-osmolar, ionic contrast medium diatrizoate-induced CC smooth muscle contractions of 57% of the control potassium chloride (124 mM) induced contractions. The low-osmolar (862 mOsm/kg) nonionic monomer contrast medium, iohexol, and the iso-osmolar (300 mOsm/kg) nonionic-dimer contrast medium, iodixanol, elicited contractions of 34% and 36% of the potassium chloride control contractions, respectively. High- and Iso-osmolar glucose solutions caused contractions of 51%, 38%, and 24% of the control, respectively. Cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) regulate CC smooth muscle contractions. These are influenced by different drugs including phosphodiesterases (PDEs), forskolin, and 3-morpholinsydnonimine hydrochloride (SIN-1). The nonspecific PDE inhibitors papaverine (0.1 mM) and theophylline (1 mM) reduced the contrast medium-induced contractions to 66% and 69%, respectively. The specific PDE inhibitor milrinone (0.1 mM) reduced the contractions to 69%; 0.1 mM forskolin and SIN-1 reduced the contractions to 34% and 41%, respectively.


CONCLUSIONS
Contrast medium induces CC smooth muscle contractions, depending mainly on the osmolality of the solution. The contractions are reduced but not abolished by elevating the intracellular cAMP and cGMP concentrations. The clinical applications in cavernosography are discussed.
Rauch
D
D
Department of Surgery, University of Wisconsin, Madison 53705, USA.
Sparwasser
C
C
Drescher
P
P
Knes
J M
JM
Madsen
P O
PO
D000818:Animals; D005576:Colforsin / Q000494:pharmacology; D003287:Contrast Media / Q000494:pharmacology*; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D003973:Diatrizoate / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007472:Iohexol / Q000494:pharmacology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects* / Q000378:metabolism; D010413:Penis; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D011817:Rabbits; D014283:Triiodobenzoic Acids / Q000494:pharmacology
D003287:Contrast Media; D010726:Phosphodiesterase Inhibitors; D014283:Triiodobenzoic Acids; D003973:Diatrizoate; D005576:Colforsin; D007472:Iohexol; D000242:Cyclic AMP; D006152:Cyclic GMP; C044834:iodixanol