Ultrastructural study of the mucification of the stratified epithelium of the mouse vagina.

After transplacental treatment of mice with estrogens, a heavy mucification was found in the fornices of the vaginae of the offspring. The resulting mucified stratified epithelium is described by light and electron microscopy. It consists of two different cell types: cells forming mucus on top of cells forming tonofilaments. Mucus formation is usually attributed to treatment with progestagens, or with the estrogens combined with vitamin A. Estrogen treatment per se has been shown to be responsible for tonofilament formation. Our unexpected findings are discussed against the background of different theories of development of vaginal epithelium as well as their possible interpretation as beginning of adenosis.