Estrogen Effects on Sister Chromatid Exchanges in Mouse Uterine Cervical and Kidney Cells

Uterine cervical fibroblasts and kidney cells from 3-to 4-day-old, previously untreated or phenobarbital [(PBA) CAS: 50-06-6]-treated female NMRI mice were cultured in vitro in the presence of diethylstilbestrol [(DES) CAS: 56-53-1] or 17β-estradiol [(E2) CAS: 50-28-2]. DES at 10−7 M in the culture medium increased the number of sister chromatid exchanges (SCE); no further increase was obtained with higher concentrations of DES. Pretreatment of the females with PBA resulted in an increase in SCE when DES was used in the range of 10−7 to 10−5 M. The level of this increase was significantly higher than that in fibroblasts from untreated females. E2 had no effect. DES had no effect on SCE in kidney cells from PBA-treated females. Indomethacin and α-naphthoflavone reduced the number of SCE in PBA-exposed fibroblasts to an intermediate level. The presence of both enzyme inhibitors in the medium depressed the number of SCE to the control level.