Electron microscopic observations of vaginal development in untreated and neonatally estrogenized balb/c Crgl mice

Abstract

Light and electron microscopic examinations of developing Mullerian vaginae were performed on untreated and neonatally estrogenized mice 1 to 12 days old. Vaginae of 1-day-old mice have a n undifferentiated, pseudostratified columnar epithelium which slowly differentiates in untreated mice into an apparently mucus-secreting epithelium. By day 12 the rough endoplasmic reticulum (RER), Golgi, and secretion granules are poorly developed features of the apical epithelial cells. In contrast, the stromal cells develop prominent RER and Golgi zones which in part are involved in the synthesis and secretion of collagen, which accumulates in the intercellular spaces.The effect of estradiol on developing vaginal epithelium is observed after 24 hours of exposure as an increase in RER and the Golgi. Estradiol (El accelerates the differentiation of mucus-secreting apical epithelial cells, whose apices become filled with secretory granules, and also promotes the formation of a cornifying epithelium from the underlying basal cells. This latter process is associated with a n increase in cellular proliferation, an increase in the occurrence of desmosomes and associated tonofilaments, and the development of extensive interdigitation of plasma membranes.In untreated and E-treated mice, the vaginal epithelium is separated from the stroma by a continuous, intact basal lamina. Transport of basal laminar material appears to occur via the processes of endo-and/or exocytosis in adjacent epithelial and stromal cells.

Development of the human female reproductive tract

“…One potential explanation is differential growth of Müllerian versus urogenital sinus epithelia, with UGE out-competing Müllerian epithelium. Another possibility may involve differential adhesion of basal epithelial cells of Müllerian versus urogenital sinus origin to the epithelial basement membrane mediated via hemidesmosomes (Cunha et al, 1978).…”

Electron-microscopic study on the development of permanently proliferated and cornified vaginal epithelium in mice treated neonatally with androgen

“…Ultrastructural changes in the vaginal epithelium of neonatally estrogenized mice have been reported by Takasugi and Kamishima [1973] and Cunha et al [1978], but no such changes have been reported in neonatally androgenized mice. The present experi ments, therefore, were designed to study ultrastructural changes occurring during the development of perma nently altered vaginal epithelium in neonatally androgenized mice.…”

The Role of Fgf Signaling on Epithelial Cell Differentiation in Mouse Vagina

“…In particular, cell proliferation and differentiation of female reproductive organs, such as mammary gland, uterus and vagina, are tightly regulated by estrogens (1). In vagina, estrogens induce epithelial cell proliferation in the basal layer (2). The suprabasal cells are no longer mitogenic and differentiate while moving up through the epithelium (2).…”

“…In vagina, estrogens induce epithelial cell proliferation in the basal layer (2). The suprabasal cells are no longer mitogenic and differentiate while moving up through the epithelium (2). The apical cells exhibit keratinization, and they lose their nuclei and cytoplasm, which are eventually shed from the surface (2).…”

“…The suprabasal cells are no longer mitogenic and differentiate while moving up through the epithelium (2). The apical cells exhibit keratinization, and they lose their nuclei and cytoplasm, which are eventually shed from the surface (2). The fully stratified and keratinized epithelium in the vagina resembles epidermis in the skin; however, unique and comprehensive process of this epithelial cell differentiation in mouse vagina, which is again regulated by estrogens, remains elusive.…”