Immunocytochemical Localization and Determination of Hormone-Induced Synthesis of the Sulfated Oviductal Glycoproteins

Secretory products of the oviduct provide part of the milieu for the critical events of fertilization and embryo development. Past work from this laboratory has indicated that three large sulfated glycoproteins can be isolated from rabbit oviductal fluid and are synthesized by oviductal epithelium incubated in vitro. These three glycoproteins are antigenically similar. This paper presents evidence for their localization within the oviductal tissue and their hormonal control of synthesis. Utilizing goat antiserum to these oviductal glycoproteins and the immunoglobulin-horseradish peroxidase bridge method, these macromolecules have been localized in the ampulla and isthmus of the oviduct. Ten days after ovariectomy an oviduct was removed for immunolocalization. The does were then given estradiol for the next 4 days and the second oviduct was removed. Oviducts treated with estradiol showed immunostaining of virtually all of the secretory granules within the secretory cells of the isthmus. While light level immunocytochemistry suggested the possibility of two populations of secretory granules within the ampulla because some of the granules did not show immunocytochemical staining, the more sensitive immunocytochemistry at the electron microscopic level showed staining of all granules of the ampulla and isthmus. Absorption of the antiserum with pure antigen prevented all staining. After ovariectomy and hormone withdrawal, most of the immunostaining was lost in the isthmus and virtually no staining in the ampulla was observed. Oviductal cell suspensions were made to evaluate incorporation of [35S] sulfate and [3H] leucine as a function of hormonal priming of the tissue. Estrogen-primed oviductal cells incorporated the sulfate and leucine into these specific glycoproteins.(ABSTRACT TRUNCATED AT 250 WORDS)