Penetration of the basal lamina of the uterine luminal epithelium during implantation in the rat
Article first published online: 8 FEB 2005
Copyright © 1985 Wiley-Liss, Inc.
The Anatomical Record
Volume 212, Issue 1, pages 47–56, May 1985
How to Cite
Schlafke, S., Welsh, A. O. and Enders, A. C. (1985), Penetration of the basal lamina of the uterine luminal epithelium during implantation in the rat. Anat. Rec., 212: 47–56. doi: 10.1002/ar.1092120107
- Issue published online: 8 FEB 2005
- Article first published online: 8 FEB 2005
- Manuscript Accepted: 5 DEC 1984
- Manuscript Received: 13 AUG 1984
During early stages of implantation in the rat, as in other species that form a hemochorial placenta, there is a progressive increase in intimacy between blastocyst and endometrium. After initial invasion of the uterine luminal epithelium by trophoblast cells and displacement of epithelial cells, the trophoblast comes to lie adjacent to the residual basal lamina of the displaced epithelium but does not penetrate it. After a pause at the basal lamina, this temporary barrier is breached. To study the interrelation of trophoblast, uterine epithelium, and decidual cells with the epithelial basal lamina during the time of penetration of the basal lamina, implantation sites collected on day 7 of pregnancy were oriented so that the implantation chamber could be sectioned either longitudinally or transversely. Neither trophoblast nor uterine epithelial cells have processes that extend through the basal lamina. However, flange-like processes from the decidual cells penetrate the basal lamina and underlie both trophoblast and, more rarely, epithelium. Smaller folds of the surface of decidual cells partially surround bundles of collagen fibrils oriented parallel to the long axis of the implantation chamber. Initially the area of penetration of basal lamina by decidual cell processes is quite restricted; as implantation proceeds the basal lamina becomes displaced and is sometimes not discernibl, extracellular materials accumulate, and the relationships become more difficult to follow. It is concluded that the initial breaching of the basal lamina is an activity of the decidual cells, and that contact of basal lamina with trophoblast is not necessary to permit this penetration.