Relationship of aryl hydrocarbon hydroxylase activity to benzo(a)pyrene-metabolizing activity of cells in culture.

The basal level of aryl hydrocarbon hydroxylase (AHH) activity was high in cultures of low passage hamster embryo (HE) cells but AHH inducibility by benz(a)-anthracene (BA) was low; in R72/3 rat liver cells, basal activity was low and inducibility was high. The metabolism of 3H--benzo(a)pyrene was similar in cultures of BA-induced R72/3 cells and uninduced HE cells. Thus, low AHH inducibility may not always be an indication of the cells' absolute hydrocarbonmetabolizing capacity.