Alterations in the transcriptional capacity of hepatic DNA-dependent RNA polymerase I and II by N-hydroxy-2-acetylaminofluorene.

Using hepatic RNA polymerases I and II, acetylaminofluorene modification of DNA in vitro results in reduction of RNA elongation but not in an altered frequency of incorporation of [alpha32P]ribonucleotides. In contrast, in vivo modification of RNA polymerases by a single dose of N-2-hydroxy-2-acetylaminofluorene results in an alteration of their capacity for transcribing a normal RNA product but does not affect the product size transcribed from normal or carcinogen-modified templates.