Inducibility of drug-metabolizing enzymes in the rat skin.

The influence of systemic application of chemically unrelated drugs and xenobiotics (phenobarbital (PB), rifampicin (Rifa), pregnenolone-16 alpha-carbonitrile (PCN) and 3-methylcholanthrene (MC) on drug metabolizing enzymes was investigated in the skin of rats of both sexes. The results were compared with those obtained in the liver. PB, Rifa and PCN induced the aryl hydrocarbon hydroxylase (AHH) in the skin though to a lesser extent than MC. The basal enzymic activity as well as the inducibility were considerably lower in the skin than in the liver. The activity of cytochrome c reductase was similar in all rats independently from the pretreatment. Only slight sex differences were noted: generally, the activity was higher in males. Cytochrome P-450 content of the skin could not be detected as well as various dealkylation activities.