Biliary excretion and distribution of 51Cr(III) and 51Cr(VI) in rats

The biliary excretion and distribution of 51Cr after intravenous administration of 51Cr(III) (61CrCl5) or 51Cr(VI) (Na252CrO4 . 4 H2O) was studied in rats. The cumulative biliary excretion of 51Cr reached 24 hrs after the injection was significantly higher after administration of 51Cr(VI) than after 51Cr(III) 3.51+/-0.7% and 0.51+/-0.05% of administered dose, respectively). This difference was especially due to a higher rate of biliary excretion of 51Cr in the first hours after 51Cr(VI) administration. The excretion of 51Cr via faeces was also higher after administration of 51Cr(VI) (7.35+/-0.45%) OF ADMINISTERED DOSE, AS AGAINST 4.23+/-0.23% after 51Cr(III). On the other hand, no significant difference in urinary excretion of 51Cr was found. Statistically significant differences were also observed in the distribution of 51Cr in the organism after administration of both valence states of the metal.