Aryl ether O-dealkylase activity in the skin of untreated mice in vitro

Abstract

1. O-Dealkylation of p-nitroanisole and p-nitrophenetole in 10000g supernatant preparations of mouse skin is detectable and quantifiable. The reaction is NADPH-dependent and is mediated by cytochrome P-450.

2. The rate of p-nitroanisole O-demethylation in mouse skin preparations is 2% of that in mouse liver preparations on a mg protein basis, but only 0.23% on a g of tissue basis.

3. For p-nitrophenetole O-deethylation, the cutaneous V _max is 3.8% of the hepatic V _max on a mg protein basis. The K_m values for the reaction in these two tissues are in a 3 : 1 ratio, suggesting that there are no marked qualitative differences between cutaneous and hepatic cytochrome P-450.