Effects of human follicular fluid on spermatozoa that have been coculturedwith human oviductal cells

Objective: To investigate the sequential effects of human oviductal cells a nd 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 balan ced salt solution (EBSS-BSA; control); [2] 5 hours in EBSS-BSA and 1 hour w ith hFF (hFF); [3] 5 hours with oviductal cells and 1 hour in EBSS-BSA (coc ulture); and [4] 5 hours with oviductal cells and 1 hour with hFF (sequenti al). Main Outcome Measure(s): Motility, acrosome reaction, zona binding, and ooc yte fusion. Result(s): Groups II and III spermatozoa had similar motility and were bett er than that of group I. Group IV displayed higher motility parameters than the other groups. Human follicular fluid induced acrosome reaction. The in cidence 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 sup pressed this effect of hFF. Conclusion(s): Oviductal cells maintained the fertilizing capacity of sperm atozoa, whereas hFF facilitated the fertilization process of oviductal sper matozoa. (C) 1999 by American Society for Reproductive Medicine.