EFFECTS OF NEONATAL DIETHYLSTILBESTROL EXPOSURE ON THE GROWTH OF MOUSE VAGINAL EPITHELIAL-CELLS IN SERUM-FREE COLLAGEN GEL CULTURE

Vaginal epithelial cells isolated from ovariectomized ca. 40-day-old BALB/cCrgl mice treated with 1-mu-g diethylstilbestrol (DES) or with oil vehicle alone for the first 5 days after birth were purified by Percoll density gradient centrifugation and grown as primary cultures in collagen gel matrix (CGM) with serum-free medium. Three dimensional colonies of both control and DES-exposed vaginal epithelial cells developed in the CGM. The initial proliferation rate of DES-exposed vaginal epithelial cells was significantly lower than that of the controls. However, after 10 days in culture, approximately 6.3-fold and 7.6-fold increases in cell number occurred in control and DES-exposed vaginal epithelial cells, respectively, a difference that is not significant. Deletion of bovine serum albumin, bovine insulin or mouse epidermal growth factor (EGF) resulted in decreased growth of both control and DES-exposed vaginal epithelial cells. Estradiol-17-beta (180 fM to 18 nM) did not stimulate growth of control or DES-exposed vaginal epithelial cells. When concentrations of EGF and insulin are increased in the serum-free medium, a dose-related increase in growth was observed in vaginal epithelial cells from both control and DES-exposed mice. DES-exposed vaginal epithelial cells were significantly less sensitive to insulin at two concentrations and to EGF at one concentration than control cells. Thus, neonatal DES exposure results in alterations in vaginal epithelial cells as indicated by decreased initial rate of proliferation and by altered sensitivity to EGF and insulin in vitro.