The aim of these experiments was to investigate the effects of bovine oviduct epithelial cells (OEC) derived from different segments to bind sperm binding and maintain their motility in vitro. In experiment 1, the number of sperm attached to OEC derived from isthmus or ampulla, the motility of unattached sperm during co-culture and fertilizing ability were assessed. In experiment 2, heparin treated sperm (hsp) or no treated sperm (nsp) were used to evaluate OEC binding ability of capacitated sperm. In experiment 1, regardless of their origin, approximately 65% of the sperm were attached to OEC within 2h. From 6h of co-culture, the numbers of unattached sperm on ampuUary OEC were significantly higher than those on isthmic OEC (p $lt; 0.005). From 12h of co-culture, the motility of unattached sperm on isthmic OEC were significantly higher than those on ampullary OEC(p $lt; 0.05). The cleavage rate of oocytes inseminated on OEC derived from isthmic segment was also significantly higher than those from ampullary segment (p $lt; 0.01). In experiment 2, the numbers of unattached hsp on OEC were significantly higher than those of controls (p $lt; 0.01), between 2-24h examination. From 12h of co-culture, the motility of unattached nsp were significantly greater than those of hsp (p $lt; 0.01).
These results show that bovine OEC derived from the isthmus play more important role(s) for sperm binding, maintaining motility and fertilization in vitro than those from the ampulla, and heparin induced capacitation may change sperm binding ability on OEC in vitro.
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