MEASUREMENT BY P-32 POSTLABELING OF (+ ANTI-BENZO[A]PYRENE-DIOLEPOXIDE-N-2-DEOXYGUANOSINE ADDUCT PERSISTENCE IN UNSTIMULATED HUMAN PERIPHERAL-BLOOD LYMPHOCYTES/

In order to study the relative importance of endogenous and environmen tal factors for the individual relation between DNA damage and DNA exc ision repair, a method was developed for measuring quantitatively the persistence of N-2-deoxyguanosine adducts formed in non-stimulated iso lated human peripheral blood lymphocytes after in vitro incubation wit h 0.2 mu M (+/-)anti-BPDE, applying P-32-postlabeling. Total binding o f radiolabeled (+/-)anti-BPDE to DNA and its removal has been studied previously in human peripheral blood lymphocytes, but the method prese nted here enables the direct investigation of repair of the main (+/-) anti-BPDE-DNA adduct, which is implicated in benzo[a]pyrene-induced mu tagenesis. Using this method, it was found that in lymphocytes, obtain ed from 5 individuals, most (+/-)anti-BPDE-N-2-dG adducts are removed within the first 24 h after treatment, while interindividual differenc es appear to exist in both adduct formation and rate and extent of rem oval.