Differential expression of cytochrome P-450 in proliferating and quiescent cultures of murine lung epithelial cells

Expression of the cytochrome P-450 monooxygenase activity 7-ethoxyresorufin O-deethylase (7-ERD) was surveyed in proliferating and quiescent cultures of murine cell line C-10, a non-tumorigenic line of presumed alveolar type II origin. 7-ERD activities were undetectable in subconfluent/proliferating cultures but became detectable once the cultures had become confluent and their growth had arrested due to contact inhibition. Serum deprivation of subconfluent cultures resulted in a rapid inhibition of cell proliferation and the subsequent expression of 7-ERD. These results suggest that 7-ERD expression is regulated as a function of the proliferative status of C-10 cells.