Chemotactic responsiveness of human spermatozoa to follicular fluid is enhanced by capacitation but is impaired in dyspermic semen.
OBJECTIVE
Our purpose was to study the chemotactic responsiveness of human spermatozoa from normal and pathological semen samples to follicular fluid (FF), as well as the effect exerted by capacitation on sperm chemotaxis.


METHODS
The chemotactic responsiveness of human spermatozoa to FF was tested by an accumulation assay chamber in which they were allowed to migrate through a microporous membrane and accumulate in a compartment filled with FF or control medium. The percentage of cells with hyperactivated motility among migrated sperm was objectively assessed by CASA and its relationship to the accumulation rate was studied. Single FFs were tested with single normospermic or dyspermic semen samples; the same FF was tested with different semen specimens. The influence of capacitation onto the chemotactic responsiveness to FF was investigated by comparing the accumulation rate of spermatozoa from normal and pathological samples after incubation under capacitating conditions for 1 or 6 hr.


RESULTS
Some FFs ("active" FFs) effectively attracted human spermatozoa from normospermic samples up to a dilution factor of 1:500 (v:v) with control medium. A wide range of responses was observed when the same FF was tested with different normal semen samples. A longer time under capacitating conditions increased both the chemotactic responsiveness of normal semen and its ability to undergo the acrosome reaction (AR) in response to A23187. Pathological semen had an impaired chemotactic responsiveness to "active" FF that was not enhanced by increasing the time spent under capacitating conditions. Dyspermic semen was also less responsive to A23187, a finding suggesting incomplete capacitation.


CONCLUSIONS
Chemotactic responsiveness to FF is acquired in parallel to or as part of the capacitation process. Dyspermic semen samples have an impaired capacity to achieve both capacitation and chemotactic responsiveness to follicular factors.
Tacconis
P
P
Department of Obstetrical and Gynecological Sciences, St. Anna Hospital, University of Torino, Via Ventimiglia 3, 10126 Torino, Italy. aerre99@yahoo.com
Revelli
A
A
Massobrio
M
M
Battista La Sala
G
G
Tesarik
J
J
D000001:Calcimycin / Q000494:pharmacology; D002633:Chemotaxis / Q000502:physiology*; D005260:Female; D015571:Follicular Fluid / Q000502:physiology*; D006801:Humans; D007476:Ionophores / Q000494:pharmacology; D008297:Male; D011247:Pregnancy; D013075:Sperm Capacitation / Q000502:physiology*; D013081:Sperm Motility / Q000502:physiology; D013094:Spermatozoa / Q000473:pathology / Q000502:physiology*
D007476:Ionophores; D000001:Calcimycin