32P-postlabelling determination of DNA adducts of malonaldehyde in humans: total white blood cells and breast tissue.

DNA adducts of malonaldehyde (MA) were measured in total white blood cells (TWBC) of healthy individuals from both sexes and different ages, as well as in breast tissue (BT) samples obtained from healthy females undergoing reduction mammaplasty. A large interindividual variation in adduct levels was observed. The average adduct level found in TWBC, considering both sexes and all ages was 2.6 +/- 1.2 adducts/10(7) nucleotides (n = 26). A similar average DNA adduct concentration was found in BT and amounted to 3.0 +/- 1.3 (n = 7) adducts/10(7) nucleotides. Our results show that DNA adducts of MA can be measured in humans using 32P-postlabelling in combination with nuclease P1 and reversed-phase HPLC as adduct enrichment procedures, and further validate these adducts as suitable biomarkers for the measurement of DNA damage inflicted by endogenously induced oxidative processes such as lipid peroxidation.