Intracellular calcium increase and acrosome reaction in response to progesterone in human spermatozoa are correlated with in-vitro fertilization.
In this study we have investigated responsiveness to progesterone in spermatozoa from a group of unselected male partners of couples undergoing in-vitro fertilization (IVF). We evaluated progesterone-stimulated intracellular Ca2+ ([Ca2+]i) and percentage increase in acrosome reaction in the same sperm sample used for oocyte inseminations. [Ca2+]i was measured with a fluorimetric method, while the acrosome reaction was assessed using a fluorescent probe (fluorescein isothiocyanate-labelled peanut lectin). The average percentage [Ca2+]i as well as the rate of increase in the frequency of acrosome reaction following progesterone challenge were significantly lower (P < 0.005) in the group of patients with a fertilization rate < 50%. In addition, significant correlations between the fertilization rate and the progesterone-stimulated [Ca2+]i and acrosome reaction increases (r = 0.78 and r = 0.79 respectively) were observed. Furthermore, in cases of fertilization failure, no increase of [Ca2+]i or acrosome reaction was observed in response to progesterone with the exception of one case. Our results indicate that [Ca2+]i and acrosome reaction increases in response to progesterone can be of value in the prediction of sperm fertilizing ability. As the two parameters were significantly correlated to each other (r = 0.86), the two assays have similar IVF predictive value and might be used interchangeably as a diagnostic tool in the assignment of male patients to the different kinds of assisted fertilization techniques.
Krausz
C
C
Dipartimento di Fisiopatologia Clinica, Università di Firenze, Italy.
Bonaccorsi
L
L
Luconi
M
M
Fuzzi
B
B
Criscuoli
L
L
Pellegrini
S
S
Forti
G
G
Baldi
E
E
D000177:Acrosome / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D066298:In Vitro Techniques; D007246:Infertility / Q000175:diagnosis / Q000628:therapy; D007424:Intracellular Fluid / Q000187:drug effects / Q000378:metabolism; D008297:Male; D011374:Progesterone / Q000494:pharmacology*; D011379:Prognosis; D013094:Spermatozoa / Q000187:drug effects* / Q000378:metabolism*
D011374:Progesterone; D002118:Calcium