3-Methylcholanthrene-induced ethoxyresorufin O-deethylase activity in alveolar type II cells of rabbit lung

Lungs of 3-methylcholanthrene-treated rabbits and those of untreated rabbits were digested with protease, and the cells were separated into an alveolar type II cell-rich fraction and a Clara cell-rich fraction by the use of counter-flow centrifugal elutriation. Drug oxidation activities of the cell homogenate of each fraction were examined. Marked elevation of ethoxyresorufin O-deethylase activity was found mainly in the cell homogenate of the alveolar type II cell-rich fraction after 3-methylcholanthrene treatment. The activity increased 6-fold with the drug treatment. Coumarin hydroxylase activity was found mainly in the cell homogenates of the Clara cell-rich fraction of the 3-methylcholanthrene-treated and untreated rabbits. The activity increased 3.5-fold with the drug treatment.