title: Rat liver S9 preparations contain comutagenic activity.
abstract: Rat liver S9 preparations contain material which causes enhancement of UV mutagenesis in Escherichia coli WP2. This comutagenic activity is present in S9 preparations from both uninduced and Aroclor-induced rats. Strains of E. coli which are defective in the uvr-dependent excision repair pathway fail to show comutagenic action by S9. The comutagenic material is heat-labile and non-dialyzable, suggesting that it might be protein. This differs from the small amount of mutagenic material present in rat liver S9, as the latter is dialyzable and can be demonstrated in the repair-deficient strain E. coli WP2s (uvrA).
mesh_terms: D000818:Animals; D001711:Biotransformation; D004260:DNA Repair; D004926:Escherichia coli / Q000235:genetics; D008862:Microsomes, Liver / Q000502:physiology*; D008970:Molecular Weight; D009152:Mutagenicity Tests; D051381:Rats