LECTIN-BINDING PATTERNS OF PORCINE OVIDUCT MUCOSA AND ENDOMETRIUM DURING THE ESTROUS-CYCLE

Important functions of the oviduct during reproduction include the pro vision of an optimal environment for gametes and zygotes and nutrition of the early embryo. These functions are ensured by the secretion of an oviductal fluid which is known to contain organ-specific glycoprote ins. Glycoconjugates of the apical glycocalyx are considered to play a major role in cell recognition and interaction processes. In the pres ent investigation, binding patterns of Con A, HPA, LTA, RCA I, UEA I, and WGA were studied in defined segments of the oviduct (infundibulum, ampulla, isthmus) and in the uterus during the oestrous cycle. The ca rbohydrate distribution showed regional as well as time dependent diff erences. LTA, HPA and WGA reacted strongly with Golgi regions and secr etory granules in the oviduct epithelium during the follicular phase, indicating high secretory activity. LTA, HPA, and UEA I also revealed a varying carbohydrate composition of the glycocalyx during the oestro us cycle. Prominent regional differences in glycoconjugate expression were shown in oviductal segments by LTA and HPA binding: during the fo llicular phase, LTA binding sites were only present on epithelial cell s of the isthmic segment, the ampulla and infundibulum being unreactiv e. D-N-acetyl-galactosamine residues were demonstrated on ciliated epi thelial cells of the ampulla and infundibulum exclusively during oestr us. The glycocalyx of uterine epithelial cells was clearly defined by HPA, WGA, LTA, RCA I and UEA I; LTA binding was restricted to the secr etory phase. The observation of regional and time dependent variabilit y in glycoconjugate distribution strongly indicates their specific phy siological functions in reproductive processes.