title: Murine metabolism and disposition of iron:adriamycin complexes.
abstract: Previous studies have reported antitumor activity and reduced cardiotoxicity for a putative 3:1 complex of iron:Adriamycin (ADR). We have studied the tissue distribution and metabolism of a wide variety of freshly prepared and lyophilized iron:ADR preparations after administration to BALB/c mice (ADR, 16 mg/kg i.v.). Tissue concentrations of ADR given without iron were initially highest in kidney and liver, and ADR fluorescence was lost from all tissues except the spleen with a t1/2 of 15 to 18 hr. ADR remained the major fluorescent species in liver and kidney from 0.5 to 72 hr after treatment. Freshly prepared iron:ADR (1:1) behaved similarly to ADR except for a slightly longer tissue t1/2 in heart, liver, and kidney. The tissue distribution of freshly prepared 2:1 and 3:1 iron:ADR was very different from that of ADR without iron; lung containing the highest concentrations of ADR fluorescence. Administration of freshly prepared 1:1, 2:1, and 3:1 iron:ADR resulted in some increase in adriamycinol in the liver, but ADR was always the major fluorescent species present. The tissue distribution of 1:1 iron:ADR that had been aged for 48 or 96 hr was similar to that of fresh 2:1 and 3:1 iron:ADR rather than ADR or fresh 1:1 iron:ADR. When lyophilized iron:ADR preparations were reconstituted and administered, the 0.5-hr tissue distribution of 0.1:1, 0.2:1, 0.25:1, and 0.33:1 iron:ADR was the same as ADR alone, but 0.5:1, 1:1, 2:1, and 3:1 iron:ADR were all accumulated primarily in the lung. Physicochemical studies confirm the production of microaggregated iron:ADR complexes and light microscopy allows visualization and sizing of these aggregates. We feel that trapping of these iron:ADR aggregates in the pulmonary vascular bed accounts for the observed dramatic alteration in tissue distribution. Light and electron microscopic studies confirm the intravascular sequestration of iron in pulmonary capillaries.
mesh_terms: D000818:Animals; D004317:Doxorubicin / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D005453:Fluorescence; D006651:Histocytochemistry; D007275:Injections, Intravenous; D007501:Iron / Q000032:analysis; D008168:Lung / Q000032:analysis / Q000098:blood supply; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D013194:Staining and Labeling; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: C018376:quelamycin; D004317:Doxorubicin; D007501:Iron