title: Effect of diethylstilbestrol on the frequencies of sister chromatid exchange in vitro and in vivo.
abstract: The influence of diethylstilbestrol (DES) on the SCE frequency was studied in various cell systems (V79, HTC, DON, WI-38, human lymphocytes) differing in their ability to metabolize the two promutagens benzo(a)pyrene and cyclophosphamide as well as after incubation with exogenous metabolic systems (S9 mix and peroxidase/H2O2) and in vivo on cells from the bone marrow of the Chinese hamster. DES concentrations from 10(-6) to 10(-4) M were tested. Slight SCE induction was observed only at the highest concentration (10(-4) M) of DES in human lymphocytes treated with DES for the entire culture period of 72 h and in DON cells. No increase of the SCE rate was determined in the other cell lines and in vivo. The combination with S9 mix or peroxidase/H2O2 also had no influence on the SCE frequency. These findings cast doubt on the assumption that DES is metabolized to a DNA-damaging compound subsequently leading to SCE induction. The positive findings in the SCE test are more likely to be products of an indirect and rather unspecific effect.
mesh_terms: D000818:Animals; D001564:Benzo(a)pyrene / Q000633:toxicity; D002460:Cell Line; D002869:Chromosome Aberrations; D006224:Cricetinae; D003412:Cricetulus; D003520:Cyclophosphamide / Q000633:toxicity; D004247:DNA; D004054:Diethylstilbestrol / Q000378:metabolism / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000648:ultrastructure; D008297:Male; D051381:Rats; D012854:Sister Chromatid Exchange / Q000187:drug effects*
chemical_list: D001564:Benzo(a)pyrene; D004054:Diethylstilbestrol; D003520:Cyclophosphamide; D004247:DNA