Enhancement of sulfanilamide N4-hydroxylase activity in kidney and liver microsomes of rats by pretreatment with 3-methylcholanthrene type-polychlorinated biphenyl.

N4-Hydroxylation of sulfanilamide was studied with kidney and liver microsomes of rats by means of high performance liquid chromatography. In kidney microsomes, both contents of cytochrome P-450 (448) and activity of N4-hydroxylase were markedly increased by pretreatment with 3,4,5,3',4'-pentachlorobiphenyl (PenCB) (about 4 times), although neither one was increased by 3-methylcholanthrene (3-MC) and phenobarbital (PB) pretreatments. In liver microsomes, on the other hand, both N4-hydroxylase activity and cytochrome P-450 (448) contents were increased by either PenCB or 3-MC pretreatment, whereas by PB pretreatment, N4-hydroxylase activity was not changed although cytochrome P-450 contents was increased 2-fold.