7,12-Dimethylbenz[alpha]anthracene-DNA adducts in cultured cells from mouse fetuses of different gestational ages.

Primary cell cultures prepared from individual litters of NIH Swiss mouse fetuses of different gestational ages were incubated with 7,12-[3H]dimethylbenz[a]anthracene (DMBA) for 24 h. Levels of binding of DMBA to DNA and the distribution of individual DMBA-deoxyribonucleoside adducts were similar in all cultures derived from fetuses of 13-15 days of gestation. However, in cells from fetuses at 17-19 days changes in DMBA-DNA binding were noted. In particular the syn bay region dihydrodiol epoxide of DMBA was responsible for a significantly greater fraction of the total DMBA-DNA binding in the cultures from the more mature fetuses.