Secretory function of the Fallopian tube epithelial cells in vitro

The oviduct provides a specialized environment for the survival and transport of the mammalian gametes to the site of fertilization within well defined time limits. The oviduct environment facilitates the process of fertilization and development of the preembryo. Furthermore, the spermatozoa and the pre-embryo, which differ antigenically from the mother, are not attacked by the immune system, which differentiates them from pathogens. The mechanisms by which all these complex processes are controlled are not fully understood. The disadvantage of cell culture systems for physiological study is that the original histological appearance is lost along with some endocrine and paracrine activities. Cells cultured on glass or plastic surfaces lose the polarization normally present in intact tissues. Premature senescence and de-differentiation may occur. It has been shown that extracellular matrix may stimulate proliferation and prevent dedifferentiation. The use of polarized cell cultures also enable the study of cellular orientation and protein secretion. Culture systems for polarized and non-polarized Fallopian tube epithelial cells have been developed in our laboratory. The subsequent experimental studies have shown that the presence of oviduct epithelial cells has a specific and significant stimulatory effect on sperm capacitation, reversing effects on the blockage of blastocyst formation. The exact mechanism of how the co-culture system achieves this is yet to be elucidated and in this regard, the unique oviduct proteins are possible candidates. Further studies of the epithelial cell cultures directed at the nature of the secretory behavior of these cells, are necessary in order to determine how these cells behave in vitro.