Vascular response to gadolinium-containing contrast media in an ex vivo rabbit arterial model.

RATIONALE AND OBJECTIVES. To assess the influence of gadolinium-containing magnetic resonance contrast agents on contractility of the arterial vessel wall. METHODS. Bilateral segments of rabbit carotid arteries were mounted in flow chambers, surrounded by aerated (95% O-2, 5% CO2) Krebs' solution, and per fused at a constant rate by separated and aerated Krebs' solution. Therefor e, changes in pressure of the circulating Krebs' solution indicated alterat ions of vessel wall contractility. Viability of the artery was tested by 12 4 mmol/L KCI, 3 x 10(-5) mol/L phenylephrine, and 10(-5) mol/L acetylcholin e. After a washout phase, gadopentate (n = 10) or gadoteridol (n = 10) was added to the perfusate of one carotid artery in increments of 0.1, 0.3, and 0.6 mmol/L. Concentrations up to 0.9 mmol/L and 1.2 mmol/L were tested, re spectively. The contralateral artery served as a control. To assess potenti al relaxing effects of the media, vessels were brought into a contracted st atus with 3 X 10(-5) mol/L phenylephrine and then received gadolinium chela tes. RESULTS. Potassium chloride and phenylephrine increased and acetylcholine d ecreased the pressure, indicating vasoconstriction and vasodilatation, resp ectively. After gadopentate and gadoteridol infusion, no statistically sign ificant pressure changes could be detected, ruling out any vasoconstrictor or vasodilator effect. CONCLUSIONS. Gadopentetate and gadoteridol in doses of up to 1.2 mmol/L did not alter vessel wall tone. The impact of contrast media on blood pressure , as has been shown in some clinical trials, probably is not due to direct changes in arterial wall tone.