Morphology of rabbit endocervical mucosa after mating.

The distribution and morphology of rabbit endocervical mucous cells before and after mating were studied histochemically with Alcian blue, pH 2.5, and periodic acid-Schiff (AB-PAS) and by scanning and transmission electron microscopy. Before mating, the lower and upper segments of the endocervical canal contained approximately 75% and 93% of cells engorged with AB-PAS positive granules. Two hours after mating, the percentage of histochemically positive cells decreased to less than 46% and 85%, respectively. Before insemination, mucous cells were prominent among ciliated cells and contained numerous secretory granules some of which appeared to be undergoing release through exocytosis. Granule-engorged apices of mucous cells were rarely seen after insemination. Instead, cells displayed a markedly reduced complement of mucous granules and their apical surface contained numerous exocytotic pits. In many areas, a blanket of mucous material covered mucous and ciliated cells. As for the observed variation in mucous cell distribution, these changes were predominant in the endocervical mucosa of the lower cervix. We have previously shown that both native and isolated mucous cells respond to serum with rapid and massive granule release. Degranulation of endocervical mucous cells in response to semen may play an important role in regulating sperm access to the upper reproductive tract under physiologic and pathologic conditions.