Renal Handling and Physiologic Effects of the Paramagnetic Contrast Medium Gd-DOTA

Gadolinium DOTA (Gd-DOTA) is a magnetic resonance (MR) contrast agent similar to Gd-DTPA but with greater stability in vitro. The effects of a high intravenous dose (0.5 mmol/kg) of Gd-DOTA (1360 mOsm/kg) on renal excretory function and its general systemic effects are examined in this animal study. This dose was selected to accentuate and better define the qualitative nature of these effects. A decrease in arterial pressure of 8% (131.9 ± 6.8 at 120 minutes versus a control of 142.8 ± 3.7 mm Hg, mean ± standard error of mean, no significant change in electrocardiogram (ECG) lead II, a 16% increase in renal blood flow (106.0 ± 5.4 at 7.5 minutes versus 91.2 ± 3.2 ml/min), and a decrease in arterial hematocrit of 9% (38.9 ± 1.5 at 120 minutes versus 41.9% ± 1.7%) were noted. In general, qualitatively similar effects have been noted as a nonspecific effect of other hyperosmolar solutions. The filtration fraction decreased (0.23 ± 0.01 at 7.5 minutes versus 0.28 ± 0.02) followed by a rapid return to baseline values. No significant change was noted in glomerular filtration rate throughout the experimental protocol. Urine flow increased nearly 1.5-fold and osmolal clearance (Cm) increased approximately 1.5 times. A natriuresis occurred as the fractional excretion of sodium (FENa increased from a control value of 3.5 ± 0.3 to 5.2 ± 0.5 at 7.5 minutes. The systemic and renal physiologic effects of high-dose intravenous Gd-DOTA on the kidney reflects a nonspecific, osmotically induced alteration. These data suggest that the main systemic and renal physiologic actions of Gd-DOTA are a nonspecific response to agent osmolality that is similar qualitatively to conventional, water-soluble contrast media.