Aryl Hydrocarbon (benzo[a]pyrene) Hydroxylase: a Mixed-function Oxygenase in Mouse Skin

Mouse skin contains aryl hydrocarbon (benzo[a]pyrene) hydroxylase activity which is inducible by aromatic polycyclic hydrocarbons and benzoflavones. The duration and magnitude of induction, but not the initial kinetics, are dependent on the inducer dose. The cutaneous hydroxylase activity is inhibited by carbon monoxide and requires the presence of NADPH, indicating that the enzyme is one of the mixed-function oxygenases. The highest enzyme activity was found in the superficial layer of skin which contains the sebaceous glands and the upper pilary canals. Enzyme activities were intermediate in the epidermis and lowest in the deeper dermal layers.