Objective: To investigate the sequential effects of human oviductal cells and human follicular fluid (hFF) on various sperm functions.
Design: Laboratory experimental study.
Setting: University gynecology unit.
Patient(s): Fallopian tubes were from patients undergoing tubal ligation or hysterectomy. Semen was from men attending the subfertility clinics.
Intervention(s): Spermatozoa were treated with [1] 6 hours in Earle's balanced salt solution (EBSS-BSA; control); [2] 5 hours in EBSS-BSA and 1 hour with hFF (hFF); [3] 5 hours with oviductal cells and 1 hour in EBSS-BSA (coculture); and [4] 5 hours with oviductal cells and 1 hour with hFF (sequential).
Main outcome measure(s): Motility, acrosome reaction, zona binding, and oocyte fusion.
Result(s): Groups II and III spermatozoa had similar motility and were better than that of group I. Group IV displayed higher motility parameters than the other groups. Human follicular fluid induced acrosome reaction. The incidence of acrosome reaction in group IV was significantly lower than that in group II. Group III did not affect the acrosome reaction. Spermatozoa in groups II-IV had lower zona binding capacity than those in group I. Human follicular fluid stimulated oocyte penetration, whereas oviductal cells suppressed this effect of hFF.
Conclusion(s): Oviductal cells maintained the fertilizing capacity of spermatozoa, whereas hFF facilitated the fertilization process of oviductal spermatozoa.