IMMUNOLOGICAL CHARACTERIZATION AND IMMUNOCYTOCHEMICAL LOCALIZATION OFAN OVIDUCT-SPECIFIC GLYCOPROTEIN IN THE HUMAN

The objective of the current study was to generate a polyclonal antibo dy toward a previously described 110- to 130-kilodalton (kDa) human ov iductal glycoprotein and to use the antibody to detect the protein in tissue sections, tissue culture media, and oviductal flushings. The po lyclonal antibody was generated in male rabbits against the 110- to 13 0-kDa glycoprotein partially purified from hydrosalpinx fluid. Segment s of human oviducts were either cut into 2- to 3-mm pieces and culture d for 24 h, or fixed and embedded in Araldite for light and electron m icroscopic immunocytochemistry. The protein was only present in midcyc le oviductal flushings and was most evident in culture medium samples obtained at midcycle when analyzed on Western blots. No cross-reactivi ty was observed with proteins in human serum or human endometrial and cervical explant culture media. Immunoperoxidase staining was observed in the apical granules of the secretory cells fining the oviductal lu men. No staining was noted in other parts of the oviduct or in section s of human endometrium and cervix. Indirect immunogold localization de monstrated specific clustering of gold particles over the apical granu les of the secretory cells. In summary, a polyclonal antibody to a 110 - to 130-kDa human oviductal glycoprotein was successfully generated. This protein is found in the secretory cells and is released into the oviductal lumen. The synthesis of this protein appears to require elev ated levels of estrogen and may play a role in early reproductive even ts occurring within the oviduct.