Differentiation of Vaginal Epithelium in the Normal and Hormone-Treated Rhesus Monkey1

Abstract

In ovariectomized, juvenile, or progesterone-treated animals, the vaginal epithelium consists of 2–3 layers of cuboidal cells. The basal cells rest on a comparatively straight basal lamina and have extensive interdigitation, but few desmosomes. None of the vaginal cells contain glycogen granules. The superficial cells synthesize mucous granules in close association with the Golgi complex. When estrogen is administered to spayed animals, and in the normal animals during the follicular phase of the cycle, the epithelium hypertrophies to as many as 50 layers of cells. A conspicuous basal lamina separates the epithelium from the connective tissue. As the basal cells move upward, they synthesize large amounts of glycogen, which eventually occupies extensive areas of the superficial cells. Besides glycogen, the cells synthesize keratohyalin, membrane-coating granules, and thickened plasma membranes—typical products of keratinization. The exfoliated cells, not completely keratinized, have disintegrating nuclei, some organelles, and large quantities of glycogen. If progesterone is given with estrogen to spayed animals or during the luteal phase of the normal cycle, the epithelium forms mucus rather than keratohyalin, membrane-coating granules, or thickened plasma membranes. These results can be explained by the inhibiting action of progesterone on estrogen.