7-ethoxycoumarin O-deethylation activity in viable basal and differentiated keratinocytes isolated from the skin of the hairless mouse.

Epidermal cells in suspension were prepared from the skin of hairless mice by digestion of skin strips with pronase. The viability of cells in such suspensions was routinely greater than 75%. Fractions enriched in different cell types were prepared from the original cell suspensions using metrizamide gradients and elutriation techniques. These fractions were studied histologically and enzymically. The cells of greater size both were more differentiated and had higher xenobiotic metabolizing enzyme activities. Also increasing in parallel with cell size were parameters such as protein to DNA ratios. Lowest in all respects were basal cells (size, enzyme activities, protein/DNA ratios, etc.). The present techniques seem superior to previously described methods for isolating skin cells for study of xenobiotic metabolisms and possible distribution of these metabolisms in different cell types.