Hepatic transport of the magnetic resonance imaging contrast agent Fe(III)-N-(3-phenylglutaryl)desferrioxamine B.

We have studied the hepatic transport of Fe(III)-N-(3-phenylglutaryl)desferrioxamine B (Fe-PGDF). Using 59Fe-PGDF in biliary cannulated rats we have shown that 32 +/- 2% of an iv bolus dose was excreted into the bile. In animals pretreated with a saturating dose of taurocholate, oxyphenonium, or bromosulfophthalein (BSP), 25 +/- 6%, 23 +/- 1%, or 1.6 +/- 0.8% of the dose, respectively, was excreted into the bile. Magnetic resonance images indicated that BSP blocked uptake of Fe-PGDF by the hepatocytes. Possible enterohepatic recycling of 59Fe-PGDF was investigated in linked rat experiments. All of the material excreted into the bile of the donor, 28 +/- 10% of the dose, was recovered in the gastrointestinal tract of the recipient, but none was found in its bile or urine. These results suggested that uptake of Fe-PGDF by the hepatocytes occurred via the BSP transporter and that no enterohepatic recycling of the contrast agent occurred.