Effects of piperonyl butoxide on hydroxylation of 2-acetylaminofluorene in hamster liver.

Single i.p. injection of piperonyl butoxide induces a dose dependent and prolonged inhibition of hamster liver acetylaminofluorene hydroxylation. However, this slight inhibition is the result of a 61% inhibition of acetylaminofluorene-7-hydroxylase activity and a 10 fold stimulation of acetylaminofluorene N-hydroxylase activity. This was confirmed by in vivo experiments. The DNA and RNA binding of acetylaminofluorene-C14 increased 2.1 and 2.4 fold, respectively, 16 hrs after treatment with acetylaminofluorene-C14 in combination with piperonyl butoxide.