Hydrocarbon-based oils as inducers of cutaneous aryl hydrocarbon hydroxylase

Petroleum-based oils applied to the skin of rats induced cutaneous aryl hydrocarbon hydroxylase activity. A heavy oil like Kuwait Crude induced benzo(a)pyrene (BaP) hydroxylase and diphenyloxazole (PPO) hydroxylase activities to levels obtained with Aroclor 1254, while a light oil like Fuel Oil No. 2 was less effective. Intraperitoneal injection of these oils to rats also induced hepatic aryl hydrocarbon hydroxylase activities. Inhibition of these activities by alpha-naphthoflavone, but not by metyrapone, suggests that the cytochrome induced is of the P448 type.