Carbohydrate mediation of boar sperm binding to oviductal epithelial cellsin vitro

After mating, mammalian spermatozoa are transported to the lower oviductal isthmus. Spermatozoa are sequestered at the isthmus by attaching and intera cting with oviductal epithelial cells, hence forming a sperm reservoir. In several mammalian species, specific carbohydrates mediate sperm-oviductal e pithelial cell binding. A quantitative in vitro free cell bioassay was deve loped to investigate the involvement of carbohydrate recognition in pig spe rm-oviductal epithelial cell interactions. This assay was validated. The se nsitivity of the assay was such that it was possible to discriminate betwee n different sperm concentrations and sperm-oviductal epithelial cell co-inc ubation periods, spermatozoa with damaged plasma membranes and epithelial c ells of non-reproductive origin. Optimal conditions were used to incubate s permatozoa and oviductal epithelial cells in the presence of six hexose sug ars at concentrations of 0, 2, 10 and 50 mmol l(-1). A significant (P less than or equal to 0.05) reduction in the binding of spermatozoa to the ovidu ctal epithelium was detected with 2, 10 and 50 mmol maltose l(-1), 50 mmol lactose l(-1) and 50 mmol mannose l(-1). These findings support the hypothe sis that attachment of pig spermatozoa to oviductal epithelium before ferti lization is mediated by carbohydrate recognition.