A. Revelli et al., PREINCUBATION IN PERITONEAL-FLUID DECREASES THE FOLLICULAR FLUID-INDUCED ACROSOMAL REACTIVITY OF HUMAN SPERMATOZOA, Andrologia, 29(1), 1997, pp. 43-48
The aim of this study was to determine the effects of preincubation in
peritoneal fluid on the follicular fluid-induced acrosomal reactivity
of human spermatozoa in vitro. Thirty women participating in our IVF-
ET program were given a GnRH-analogue, highly purified FSH and hCG in
order to induce superovulation. Peritoneal and follicular fluids were
aspirated during pick-up laparoscopy, centrifuged, filtered and frozen
until use. An aliquot of swim-up suspension from normospermic semen s
pecimens (n=30) was incubated with peritoneal fluid or HAM-F10 for 30-
180 min, and follicular fluid (in volumetric proportion approximately
50/50 with peritoneal fluid) was subsequently added. The percentage of
acrosomally-reacted spermatozoa was assessed using the FITC-conjugate
d Pisum sativum lectin before and after incubation in peritoneal fluid
or control medium, as well as after follicular fluid addition. Perito
neal fluid was not able to stimulate acrosomal reactivity; further, pr
eincubation in peritoneal fluid decreased, but not abolished, the foll
icular fluid-induced acrosomal reactivity. A longer pre-incubation in
peritoneal fluid was associated with a lower percentage of reacted spe
rmatozoa in response to the addition of follicular fluid. In conclusio
n, our data suggest that peritoneal fluid acts maintaining spermatozoa
in an unreacted status in the upper female genital tract. After mixin
g with follicular fluid, a phenomenon that is likely to occur at ovula
tion, peritoneal fluid reduces, but does not abolish, the stimulating
effect of follicular fluid on acrosomal reactivity.