Biology of Reproduction, Vol 23, 677-686, Copyright © 1980 by Society for the Study of Reproduction

Effect of Estradiol-17 on Endocervical Cytodifferentiation and Glycoprotein Biosynthesis in the Ovariectomized Rabbit

¹ Division of Reproductive Biology, Department of Obstetrics and Gynecology and Department of Pathology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104

In this study we tested the hypothesis that estrogen affects the cytodifferentiation of endocervical cell types. Applying a unit gravity sedimentation procedure to pronase-dispersed endocervical cells, four cell types were isolated from estrous rabbits. Two of these cell types contained histochemically distinguishable (periodic acid-Schiff; PAS) glycoproteins and were designated vacuolated and granular PAS-positive cells. The third cell type, which did not contain secretory granules, was designated as vacuolated PAS-negative; the fourth cell population consisted of ciliated cells. These different cell populations and their biosynthetic capabilities were compared with endocervical cell populations from ovariectomized and ovariectomized estrogen-treated animals. As a result of ovariectomy, the endocervix was composed of ciliated cells and of a population of degranulated cells that were no longer involved in mucus glycoprotein biosynthesis, as indicated by negligible incorporation of a glycoprotein radiolabeled precursor ([¹⁴C]-N-acetyl-D-glucosamine). Estrogen administration (5 µg estradiol-17animal/12 h for 10 days) to ovariectomized rabbits resulted in the restoration of endocervical cell types whose morphological and biosynthetic characteristics were comparable to those of cells from estrous rabbits. Collectively, these data support the hypothesis that estrogen plays a significant role in maintaining both the cytoarchitecture and the biosynthetic activity of endocervical epithelium. This study also shows that the ovariectomized rabbit may represent a useful model in which to study the mechanism of estrogen action on endocervical mucus glycoprotein biosynthesis.

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ACKNOWLEDGMENTS This research was supported by NIH Grant HD-06274 (S.V.N.) and a grant from the Ford Foundation (B.S.C.). The authors gratefully acknowledge the assistance of Mrs. Janice Sowinski in preparing the electron micrographs and the secretarial assistance of Ms. Patricia Park. We also wish to thank Dr. George L. Flickinger for assistance in evaluation of steroid radioimmunoassay data and for helpful criticism of this manuscript.