Characterization and induction of aryl hydrocarbon (benzo(a)pyrene) hydroxylase in rabbit bone marrow.

Benzo(a)pyrene hydroxylase activity was found in the bone marrow of control and 3MC-induced New Zealand white rabbits. This activity was localized in the microsomal fraction, was NADPH dependent and CO sensitive. The reaction was inhibited by 7,8-benzoflavone indicating that it was mediated by the 3MC-inducible form of cytochrome P-450. BP hydroxylase activity in rabbit bone marrow was located primarily in white cells, and was considerably higher than that previously reported for cultured human lymphocytes and monocytes. A possible role for the bone marrow mixed-function oxygenase in the production of hemopoietic toxicity is considered.