Autoradiographic analysis of hormone-independent development of the mouse vaginal epithelium in organ culture.

Abstract

Epithelial development was studied in organ cultures of vaginas from ovariectomized mice. In defined medium without estrogen, basal cell proliferation and formation of a stratified squamous epithelium occurred spontaneously in a high percentage of cases. During this “spontaneous” development, the length of the cell cycle and duration of DNA synthesis were the same as those occurring in vivo in response to estrogen. RNA synthesis was also stimulated. Thus, spontaneous development in vitro appears to resemble estrogen-induced development in vivo both qualitatively and quantitatively. In vitro, estrogen was found to have no detectable effect on the atrophic epithelium. In addition, estrogen was unable to halt degeneration of the fully developed epithelium on explants that had been estrogen-primed in vivo. The results suggest that both hormone-dependence and ability of hormones to induce a response are dependent on cell environmental factors.