Absorption and metabolism of intratracheally instilled cortisol and beclomethasone dipropionate in the isolated perfused rat lungs.

The fate of [4-14C]-cortisol and [16,16 alpha-3H]-beclomethasone dipropionate following intratracheal application of the substrates into isolated perfused rat lungs was studied. Both substrates were transferred to the perfusion medium, cortisol at a much higher rate than beclomethasone dipropionate. The proportion of different metabolites of the total radioactivity was larger with beclomethasone dipropionate in both the perfusion medium and the lung tissue. The lungs are considered to have a catabolic role in cortisol metabolism.