• Oestradiol;
  • olfactory nasal mucosa;
  • rats

Abstract: The metabolism of 4–14C–oestradiol in the rodent respiratory tract has been investigated in vitro. Using thin–layer radiochromatography, at least 3 and 2 metabolites were found at incubation with slices from the rat olfactory mucosa and lung, respectively. Autoradiography of the nasal region of rats injected intravenously with 4–14C–oestradiol showed a high level of radioactivity in the mucosa covering the respiratory region, and in the subepithelial parts of the olfactory mucosa. Autoradiography of rat and mouse lung slices incubated with 4–14C–oestradiol showed that a selective localization of radioactivity occurred in the bronchial mucosa. The radioactivity in the mucosa of the respiratory tract was reversibly bound and could be extracted with organic solvents