Influence of contrast media on the response of rat renal arteries to endothelin and nitric oxide: influence of contrast media.
OBJECTIVE
Contrast media (CM) such as diatrizoate meglumine (DTZ) or iohexol can cause renal vasoconstriction in vivo, and this may initiate CM-induced nephropathy. Endothelin-1 (ET-1), a vasoconstrictor, and nitric oxide, a vasodilator, are key modulators of renal circulation. We tested the hypothesis that CM enhances arterial responses to ET-1, or diminishes responses to nitric oxide.


METHODS
A video dimension analyzer continuously recorded changes in diameter of isolated, pressurized rat interlobar renal arteries (200-400 microm diameter) superfused with combinations of CM, ET-1, nitric oxide, and other vasoactive agents.


RESULTS
Superfusion of arteries with 3.3% DTZ, but not with 3.3% iohexol, enhanced their sensitivity to ET-1 by approximately twofold, as assessed by shifts in concentration-response curves. Both DTZ and iohexol decreased the sensitivity of arteries to nitric oxide by approximately threefold. Neither DTZ nor iohexol affected arterial sensitivity to other vasoconstrictors (phenylephrine, potassium) or vasodilators (forskolin, diltiazem).


CONCLUSIONS
Diatrizoate meglumine and iohexol may induce or augment renal vasoconstriction in part by causing selective alterations in arterial sensitivity to ET-1 and to nitric oxide.
Murphy
M E
ME
Department of Pharmacology, The Albany Medical Center, New York 12208, USA. MMurphy@ccgateway.amc.edu
Tublin
M E
ME
Li
S
S
D000704:Analysis of Variance; D000792:Angiography / Q000295:instrumentation; D000818:Animals; D003287:Contrast Media / Q000494:pharmacology*; D003974:Diatrizoate Meglumine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D019332:Endothelin-1 / Q000494:pharmacology*; D007472:Iohexol / Q000494:pharmacology; D008297:Male; D009569:Nitric Oxide / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012077:Renal Artery / Q000187:drug effects* / Q000502:physiology; D012680:Sensitivity and Specificity; D014661:Vasoconstriction
D003287:Contrast Media; D019332:Endothelin-1; D009569:Nitric Oxide; D003974:Diatrizoate Meglumine; D007472:Iohexol