RT Journal Article SR Electronic T1 Binding of radioactivity from (14C)thiourea to rat lung protein. JF Drug Metabolism and Disposition JO Drug Metab Dispos FD American Society for Pharmacology and Experimental Therapeutics SP 119 OP 123 VO 4 IS 2 A1 M A Hollinger A1 S N Giri A1 F Hwang YR 1976 UL http://dmd.aspetjournals.org/content/4/2/119.abstract AB Binding of radioactivity from [14C]thiourea (TU) to rat lung protein was found to occur in vitro. Two binding sites are present. One possesses low affinity/high capacity while the other is characterized by high affinity/low capacity. In vitro binding of [14C]TU to lung protein can be antagonized by the presence of either unlabeled congeners (alpha-napthylthiourea or phenylthiourea) or thiol-containing compounds (cysteine, reduced glutathione). Conversely, depletion of lung-reduced glutathione by means of diethyl maleate administration results in elevated protein binding. Prior administration (24 hr) of a sublethal dose of TU (which renders tolerance to a subsequent lethal dose in vivo) results in a decrease in in vitro binding of radioactivity from [14C)TU to lung protein. In addition, immature rats, which are less sensitive to the edematogenic effect of TU, bind less radioactivity from [14C]TU to lung protein when the drug is administered in vivo. These results suggest a correlation between [14C]TU binding to lung protein and the pathophysiological effect of the drug in the lung.