Effects of the magnetic resonance contrast medium ferrioxamine methanesulfonate on systemic and renal hemodynamics in the anesthetized dog.
Ferrioxamine methanesulfonate (S-FDF) is a new magnetic resonance (MR) contrast agent developed to improve magnetic resonance imaging of the abdomen and pelvis. This stable complex of deferoxamine methanesulfonate and iron is excreted in the urine by glomerular filtration modified by active renal tubular resorption. This study examines the acute systemic and renal hemodynamic responses to this agent after intravenous administration either as an infusion of 25 mg/kg over 5 minutes or as a rapid bolus at a dose of 50 mg/kg. In eight anesthetized dogs, renal plasma flow (RPF) was measured with an electromagnetic flowmeter, and GFR was determined by the renal extraction of technetium-99m-DTPA. Mean arterial pressure (MAP), pulse rate, and a lead II ECG were assessed. At a dose of 25 mg/kg over 5 minutes, MAP decreased significantly (control 146.0 +/- 6.5 mm Hg vs. 107 +/- 18 mm Hg at 2 minutes; P less than .05). In two of the eight animals, the MAP dropped below 60 mm Hg. Significant decreases in GFR and RPF also were noted. All four of the animals receiving the rapid injection of S-FDF experienced profound hypotension (MAP less than 50 mm Hg). The drop in heart rate from 152 +/- 11.6 bpm to 121 +/- 4.9 bpm was associated with a marked depression of the ST wave in the lead II ECG. Further animal studies are needed to assess the mechanism of toxicity and a potential synergism of action with pentobarbital anesthesia.
Niedrach
W L
WL
Department of Urology, University of Rochester Medical Center, New York 14642.
Tonetti
F W
FW
Katzberg
R W
RW
Morris
T W
TW
Ventura
J A
JA
Totterman
S
S
Cos
L R
LR
D000818:Animals; D003287:Contrast Media / Q000494:pharmacology*; D003676:Deferoxamine / Q000494:pharmacology*; D004285:Dogs; D005260:Female; D005290:Ferric Compounds / Q000494:pharmacology*; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D008279:Magnetic Resonance Imaging; D008297:Male; D012079:Renal Circulation / Q000187:drug effects*
D003287:Contrast Media; D005290:Ferric Compounds; C002577:ferrioxamine B; D003676:Deferoxamine