The activity of aryl hydrocarbon hydroxylase in adult human skin.

1 Aryl hydrocarbon hydroxylase (AHH), a mixed-function oxidase system, has been identified in microsomal preparations of adult breast skin and foreskin. 2 Separation of dermis from epidermis by stretching, showed that AHH activity in human skin is almost exclusively located within the epidermis. 3 Preincubation of whole chopped skin with benzanthracene (5 muM to 100 muM) using a tissue culture system was accompanied by a concentration dependent increase in AHH activity. 4 Although there was no significant difference in AHH activity between the two sites, individuals differed markedly from one another in activity at any one site. Activity was observed to be positively correlated with age.