P-32 POSTLABELED DNA-ADDUCTS IN LIVER OBTAINED FROM WOMEN TREATED WITH TAMOXIFEN

P-32-Postlabelling of DNA extracted from the livers obtained from seve n women receiving tamoxifen (20 mg either once or twice daily) was com pared with liver DNA from seven individuals not receiving this drug. I n all but one of the treated women, tamoxifen and its N-desmethyltamox ifen metabolite could be detected in liver extracts by high performanc e liquid chromatography; none was detected in control samples. The tot al level of P-32-postlabelled DNA adducts extracted from the tamoxifen treated women ranged between 18-80 adducts/10(8) nucleotides. The pat tern of P-32-postlabelled adducts was not the same as those seen in ra ts dosed with this drug. There was no significant difference in the le vel of DNA damage between the tamoxifen treated and control groups. Al though only a small number of subjects has so far been examined it app ears that women are less susceptible to liver DNA damage caused by tam oxifen than rats.