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

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