%0 Journal Article %A MANNFRED A. HOLLINGER %A SHRI N. GIRI %A MICHAEL ALLEY %A EDWIN R. BUDD %A FREDA HWANG %T TISSUE DISTRIBUTION AND BINDING OF RADIOACTIVITY FROM 14C-THIOUREA IN THE RAT %D 1974 %J Drug Metabolism and Disposition %P 521-525 %V 2 %N 6 %X Radioactivity from 14C-thiourea has been shown to bind selectively to liver, kidney, and lung resulting in elevated radioactivity half-lives in these tissues compared to that of plasma. Binding of 14 to tissue protein parallels tissue retention of radioactivity. The 102,000g supernatant fraction of lung contains the highest proportion of radioactivity both in terms of absolute counts and disintegrations per min per 100 µg of protein. The majority of radioactivity in the 105,000g supernatant fraction appears to be bound to a small polypeptide with a molecular weight of approximately 1000-1500. The edematogenic effect of thiourea may, therefore, involve binding of the drug or a metabolite to a lung polypeptide. This interaction may directly or indirectly lead to increased permeability of capillary endothelial and alveolar barriers. Copyright © 1974 by The American Society for Pharmacology and Experimental Therapeutics %U https://dmd.aspetjournals.org/content/dmd/2/6/521.full.pdf