Effects of human oviductal cell coculture on various functional parameters of human spermatozoa.

OBJECTIVE: To investigate the effect of human oviductal cells on various sperm functions in vitro.

DESIGN: Controlled experimental laboratory study.

SETTING: University gynecology unit.

PATIENT(S): Women undergoing tubal ligation or hysterectomy and men who were visiting our subfertility clinics.

INTERVENTION(S): Coculture of oviductal cells with human spermatozoa in vitro; sperm functions were determined after coculture.

MAIN OUTCOME MEASURE(S): Capacitation, acrosome reaction, zona binding, and oocyte fusion.

RESULT(S): Oviductal cells and conditioned medium induced more spermatozoa to capacitate than did control medium. Although there was no difference in the spontaneous acrosome reaction between any of the groups, the coculture group had a lower percentage of acrosome-reacted spermatozoa after calcium ionophore challenge than did the control and conditioned medium groups. Coculture and conditioned medium treatment reduced the number of spermatozoa bound to the zona pellucida. The penetration rate and penetration index of the control spermatozoa in the zona-free hamster oocyte penetration test were significantly higher than that of the cocultured or conditioned medium-treated spermatozoa.

CONCLUSION(S): Human oviductal cells promoted capacitation, stabilized the acrosome, and suppressed binding to the zona pellucida and fusion with the oocyte in vitro.