PARENT SESSION
Preimplantation Embryo/Fetal Development
185
BOVINE TROPHOBLAST CELLS EXPRESS OXYTOCIN RECEPTORS (OTR) AND MATERNAL CARUNCLES EXPRESS INTERFERON-
(IFN) THROUGHOUT GESTATION .
Fuchs, Anna-Riitta1, Dantzer, Vibeke2, Pfarrer, Christiane 3, Balvers, Marga 4, Ivell, Richard4, 1 2 3 4
ABSTRACT- Placentomes were obtained from dairy cows on days 22, 26, 35, 42, 48, 90, 120, 180, 185, 218, 220, 250 and at parturition. Tissues were fixed in 4% buffered formalin and embedded in paraffin. Serial sections were cut and mounted on APES-coated slides. Immunohistochemistry for OTR was performed using a monoclonal antibody (2F8) and for IFN- using a polyclonal antibody (Gift from Dr. A.P. Alexenko). In situ/ hybridization was carried out for OTR using a digoxigenin labeled probe. Strong staining for ir OTR was seen on all days in the cells of the trophoblast and chorionic villi, arcades in particular. There was no expression of OTR in maternal epithelial cells until mid and late pregnancy when diffuse staining appeared also in the connective tissue. Strong staining for ir IFN was seen in the maternal epithelium in early and mid pregnancy, at later stages ir IFN staining was weaker and more diffuse and present also on the fetal side. We have reported earlier that binding of labeled OT to caruncles remains low during pregnancy while in noncaruncular endometrium it is rising throughout gestation. The presence of IFNin the caruncular tissues during pregnancy explains the low levels of OTR in that tissue.
KEY WORDS: interferon-tau , maternal placenta , bovine pregnancy, oxytocin receptors