Immunological characterization and immunocytochemical localization of oviduct-specific glycoproteins in the baboon (Papio anubis).

Oviducts obtained from estradiol-treated ovariectomized baboons synthesize and release a family of high mol wt (100,000-130,000) glycoproteins during short term explant culture. The objective of this study was to make a polyclonal antibody to these glycoproteins and then use the antibody to determine the presence of the glycoproteins in oviduct flushings, tissue culture media, and tissues obtained from cycling and steroid-treated baboons. Oviduct culture medium proteins from estradiol-treated baboons were separated on one-dimensional polyacrylamide gels and transferred to nitrocellulose membranes. The region containing the glycoproteins was cut out, solubilized in dimethylsulfoxide, mixed with Freund's adjuvant, and injected at 2-week intervals into a male rabbit. The anti-serum used in this study was obtained 6 weeks after the initial injection and cross-reacted with antigens on Western blots of oviduct flushings and oviduct culture media obtained from follicular stage and estradiol-treated baboons. The antigens were absent in oviduct flushings obtained from luteal stage, ovariectomized and estradiol-primed baboons treated with estradiol and progesterone or progesterone alone. The antigens were not detected on Western blots of other reproductive and nonreproductive tract culture media or in serum obtained from follicular stage or estradiol-treated baboons. Immunoperoxidase staining was limited to discrete granules in the apical cytoplasm of secretory cells in oviducts obtained from follicular stage and estradiol-treated baboons. Thus, the secretory cells of the baboon oviduct synthesize and secrete a family of estradiol-dependent oviduct-specific glycoproteins that may have potential functional significance during fertilization and embryo development.