AN IMPROVED P-32 POSTLABELING HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY METHOD FOR THE ANALYSIS OF THE MALONDIALDEHYE-DERIVED 1,N-2-PROPANODEOXYGUANOSINE DNA ADDUCT IN ANIMAL AND HUMAN TISSUES/

Malondialdehyde (MDA) is a major lipid peroxidation product that is mu tagenic and tumorigenic. The MDA-modified DNA adduct, 3-(2-deoxy-beta- D-erythro-pentofuranosyl)pyr [1,2-alpha]purin-10(3H)-one (M(1)G), has been detected in human tissues and may be a marker of human cancer ris k. In this paper, we describe an improved P-32-postlabeling/HPLC metho d for sensitive detection and quantitation of this MDA-modified 2'-deo xyribonucleotide adduct. Specific improvements include (i) unequivocal structural identification of the postlabeling products, both the 3',5 '-bisphosphate of M(1)G (MDA-3',5'-dGDP) and the 5'-monophosphate of M 1G (MDA-5'-dGMP); (ii) efficient separation of the P-32-postlabeling p roducts by HPLC; and (iii) the incorporation of a synthetically prepar ed MDA-modified DNA (or the 3'-monophosphate of M(1)G) with a known mo dification level as an internal standard. This improved quantitative m ethodology provides high intra- and inter-assay reproducibility and ha s been applied to the analysis of this adduct in rodent and human samp les.