Relationship between the zona pellucida (ZP) and ionophore A23187-induced acrosome reaction and the ability of sperm to penetrate the ZP in men with normal sperm-ZP binding.
OBJECTIVE
To determine whether the proportions of sperm undergoing the acrosome reaction (AR) on the zona pellucida (ZP) or on exposure to the calcium ionophore A23187 correlate with sperm-ZP penetration in men with normal sperm-ZP binding.


METHODS
Sperm samples from 14 fertile, 50 normozoospermic, and 21 teratozoospermic men with normal sperm-ZP binding were used to study ZP and ionophore-induced AR and sperm-ZP penetration.


METHODS
University research unit associated with a clinical infertility and IVF program.


METHODS
The proportion of sperm undergoing the AR induced by ZP and A23187, the number of sperm bound to and penetrating into the ZP, the proportion of ZP penetrated by sperm, and semen characteristics were analyzed.


RESULTS
There were highly significant correlations between the percentage AR of sperm bound to the ZP and both the proportion of ZP penetrated and average number of sperm penetrating per ZP (Spearman r = 0.697 and 0.703). In contrast, A23187-induced AR did not correlate with either ZP-induced AR or sperm-ZP penetration. Although sperm concentration in semen correlated with both ZP-induced AR and sperm-ZP penetration by Spearman test, it was not significant in multivariate regression analyses.


CONCLUSIONS
Ionophore A23187-induced AR does not correlate with either ZP-induced AR or sperm-ZP penetration. The ZP-induced AR is correlated highly with sperm-ZP penetration. Testing ZP-induced AR may be useful for assessing infertile men with normal sperm-ZP binding. In particular, it will identify failure of ZP penetration because of specific defects of the AR on the ZP.
Liu
D Y
DY
Department of Obstetrics and Gynecology, University of Melbourne, Australia.
Baker
H W
HW
D000177:Acrosome / Q000187:drug effects / Q000502:physiology*; D000001:Calcimycin / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007476:Ionophores / Q000494:pharmacology*; D008297:Male; D012044:Regression Analysis; D013075:Sperm Capacitation / Q000187:drug effects / Q000502:physiology; D013076:Sperm Count; D013081:Sperm Motility / Q000187:drug effects / Q000502:physiology; D013084:Sperm-Ovum Interactions / Q000187:drug effects / Q000502:physiology*; D015044:Zona Pellucida / Q000187:drug effects / Q000502:physiology*
D007476:Ionophores; D000001:Calcimycin