LOCALIZATION OF ANTIGEN DEFINED BY A MONOCLONAL-ANTIBODY TO HUMAN 32-KDA INSULIN-LIKE GROWTH FACTOR-BINDING PROTEIN IN THE SHEEP UTERUS AT PREIMPLANTATION STAGES OF PREGNANCY

Employing a murine monoclonal antibody to pregnancy-associated endometrial α1-globulin, a 32-kDa insulin-like, growth factor-binding protein (IGF-BP) and major product of the decidualized endometrium in the human, reactivity has been detected in the luminal epithelium of the sheep endometrium during the preimplantation period of pregnancy. Staining was associated with supranuclear regions of the cytoplasm. Reactivity was restricted to the pregnant uterus and was distributed throughout the luminal epithelium in both caruncular and intercaruncular regions. The reactivity was absent from endometrial glands in intercaruncular regions. Staining was first detected at day 10, peaked at day 14 of gestation and was absent by day 16. The implications of the induction of the production of this protein by the preimplantation blastocyst in the luminal epithelium is discussed with reference to the potential role of IGF-BP in IGF action in the embryo. © 1990, Baillière Tindall. All rights reserved.