Some Ultrastructural Observations on Cellular Interaction Between Trophectoderm and Uterine Epithelium During Preimplantation in Rat

Abstract: The blastocystic trophoblast cells consist of different types of cells according to their structural architecture and their functional specialisation: a) supporting, preventing and feeding functions; b) signalization, polarisation, and depolarisation functions between blastocyst and uterine; c) immunological acceptance or rejection and secreting functions. The aim of this study was to investigate the ultrastructure of cellular interaction between mural trophoblast/trophectoderm cells of blastocyst and uterine epithelium in rat. Tissue samples obtained from rats on day 5 of pregnancy were studied ultarstructurally. In contrast to the polar trophoblast cells exhibiting degeneration according to implantataion progress, some mural trophoblast cells play an important role in the cellular interaction taking place between the uterine epithelium and blastocyst. The ultrastructural evidence, that structural diversification in blastocystic ring change according to the implantation period and these ultrastructural properties, suggests that the functional diversification is very important for implantation