TY - JOUR T1 - Target cells for the polychlorinated biphenyl metabolite 4,4'-bis(methylsulfonyl)-2,2',5,5'-tetrachlorobiphenyl in lung and kidney. JF - Drug Metabolism and Disposition JO - Drug Metab Dispos SP - 490 LP - 496 VL - 13 IS - 4 AU - I Brandt AU - J Lund AU - A Bergman AU - E Klasson-Wehler AU - L Poellinger AU - J A Gustafsson Y1 - 1985/07/01 UR - http://dmd.aspetjournals.org/content/13/4/490.abstract N2 - Light microscope autoradiography was used to determine the cellular localization of the polychlorinated biphenyl metabolite 4,4'-bis([14C] methylsulfonyl)-2,2',5-5'-tetrachlorobiphenyl ([3H]TCB) in the lung and kidney of mice and rats. Microautoradiograms prepared from thaw-mounted freeze sections showed that the radioactivity in the lung was localized in the bronchiolar lumen and epithelium. In methacrylate sections (74-82% of radioactivity extracted), a highly selective labeling was registered in the apical cytoplasm of the Clara cells. A pronounced labeling was present also in certain goblet-like cells containing periodic acid-Schiff-positive granules. Gel permeation chromatography and density gradient centrifugation showed that 80-95% of the radioactivity in lung lavage fluid was bound to a specific protein previously characterized in rat and mouse lung cytosol. The protein appeared to be enriched in the lavage fluid, as compared to lung cytosol. These data suggest that [3H]TCB binds to a protein residing in the Clara and goblet-like cells and that the labeled TCB-protein complex is subsequently secreted into the airway lumen. As shown by microautoradiography, the radioactivity in the kidney was confined to a restricted portion of the nephron, predominantly to the apical region of the proximal tubular cells. ER -