Distribution, retention, and fate of 2-aminoanthracene in rats after inhalation

The distribution, retention, and fate of 2[3H]aminoanthracene (2-AA) were determined in male Fischer-344 rats after inhalation exposure (70 micrograms/liter; activity mass median diameter = 2.1 micron) for 30 min. Radioactivity was found in the turbinates, trachea, lungs, liver, kidneys, and gastrointestinal tract 20 min after exposure. Lower quantities of radioactivity were found in fat, brain, testes, and muscle. Inhaled 2-AA was excreted predominantly in feces (80%). The remaining 2-AA was excreted in urine. Organic soluble radioactivity was released from urinary conjugates after treatment of urine with acid and with beta-glucuronidase. This result suggests that glucuronides of both ring- and N-hydroxy-2-AA were excreted. The remaining radioactivity was water soluble and accounted for approximately one-half of the total urinary radioactivity. The organic soluble radioactivity found after hydrolysis indicated that inhaled 2-AA is extensively metabolized by rats after inhalation and excreted as conjugated metabolites. Eighty-three percent of orally administered material was absorbed into the body from the GI tract; thus, material cleared by mucociliary action after inhalation would contribute to total body burden. 2-AA, a nitrogen substituted polycyclic aromatic hydrocarbon (PAH), was very similar to other PAHs in its rapid distribution throughout the body and in its route of excretion after inhalation.