DRUG-METABOLISM IN SKIN - COMPARATIVE ACTIVITY OF THE MIXED-FUNCTION OXIDASES, EPOXIDE HYDRATASE, AND GLUTATHIONE S-TRANSFERASE IN LIVER AND SKIN OF THE NEONATAL RAT

  • 1 January 1981
    • journal article
    • research article
    • Vol. 9  (4) , 311-314
Abstract
Aryl hydrocarbon hydroxylase (AHH) activity in the skin of neonatal rats was compared to that in epidermis, dermis and other body tissues. Following topical application of benzo[a]pyrene (BP) or the polychlorinated biphenyl mixture Aroclor 1254 there was induction of AHH in each tissue studied. There was a greater increase in the activity of skin enzyme as compared to other extrahepatic tissues. When whole-organ activity (pmol of 3-OH-BP/min per whole organ) was considered, skin represented 2, 21 and 27% of whole body activity in control, BP-treated and Aroclor 1254-treated animals, respectively. Skin microsomes from control rats exhibited 2, 0.5, 24 and 6% of corresponding liver microsomal AHH, 7-ethoxycoumarin deethylase, NADPH-cytochrome c reductase and epoxide hydratase activities, respectively. Glutathione S-transferase activity in skin cytosol was 15% of the corresponding hepatic activity. Following topical application of Aroclor 1254 there were increases in the activity of AHH and 7-ethoxycoumarin deethylase in the skin and the liver. Glutathione s-transferase (40-60%) and epoxide hydratase (83-94%) activities in neonatal rat liver were induced by skin application of Aroclor 1254.