Title: Flow cytometry reveals subpopulations of murine epidermal cells that are refractory to induction of cytochrome P-4501A1 by beta-naphthoflavone.

Authors: Stauber, K L; Laskin, J D; Yurkow, E J; Thomas, P E; Laskin, D L; Conney, A H

Published In J Pharmacol Exp Ther, (1995 May)

Abstract: Topical application of beta-naphthoflavone to CD-1 mice induced an 87-fold increase in epidermal 7-ethoxyresorufin O-dealkylation activity per cell and a many-fold increase in epidermal cytochrome P-4501A1 (CYP1A1) concentration. Flow cytometric analysis of individual epidermal cells from acetone-treated and beta-naphthoflavone-treated mice using a monoclonal antibody for CYP1A1 indicated that 50% to 60% of the isolated epidermal cells were refractory to beta-naphthoflavone induction of CYP1A1. Examination of the differences between responsive and nonresponsive epidermal cells from beta-naphthoflavone-treated mice revealed that 70% of the low CYP1A1-containing cells (noninduced) separated by flow cytometry were basal cells and only 12% were suprabasal differentiated cells. In contrast, about 50% of the high CYP1A1-containing induced cells separated by flow cytometry from the epidermis of mice treated with beta-naphthoflavone were suprabasal cells and 35% were basal cells. These results indicate that topical application of beta-naphthoflavone increased the level of CYP1A1 in about 80% of the separated suprabasal cells and in about 35% of the separated basal cells.

PubMed ID: 7752102

MeSH Terms: Animals; Benzoflavones/pharmacology*; Blotting, Western; Cell Separation; Cytochrome P-450 Enzyme System/biosynthesis*; Enzyme Induction; Epidermis/cytology; Epidermis/drug effects*; Epidermis/enzymology; Female; Flow Cytometry; In Vitro; Mice; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.; beta-Naphthoflavone