Effect of Vitamin A and E on the Interaction Between 2-Acetylaminofluorene and Rat Liver DNA in Vivo

Binding of the hepatocarcinogen 2-acetylaminofluorene(AAF) to the DNA of rat liver homogenates was examined in vivo. Animals fed low and high concentrations vitamin A and E for 28 days and DNA isolated 2 hr following a single i.p. injection of[9-¹⁴C]acetylaminofluorene. The precipitated DNA was dissol-ved in MUP, blended and passed through an HAP column. UV-absorbing material eluted with 0.48M Nap. Following dialysis, the fraction was enzymatically hydrolyzed purified by Sephadex LH-20 chromatography and the adducts were separated by HPLC. The ability of vitamin A and E on the binding of AAF to liver DNA in vivo was markedly inhibited the formation of the proximate carcinogen, N-(deoxyguanosine-N²-yl) AAF(C-8 adduct). Vitamin A at higher concentration(2,000I.U.)exerted a stronger inhibitory effect on the formation C-8 adducts. A similar inhibition pattern was observed in higher concentration vitamin E administered rats. The data presented here demonstrated marked inhibits in the pattern of C-8 deoxyguanosine adduct formation during the premaligment phase of 2-AAF carcinogenesis.