Hyperactivated motility of sperm from fertile donors and asthenozoospermic patients before and after treatment with ionophore

Hyperactivated motility of capacitated sperm was studied before and after contact for 30 min with the Ca2+ ionophore A23187. Sperm from fertile donors and asthenozoospermic infertile patients were incubated in the presence of increasing concentrations of A23187 in the medium. At 5-10 microM, the ionophore induced a significant increase (P less than 0.05) in the percentage of hyperactivation of sperm from asthenozoospermic subjects. Higher concentrations (20 and 30 microM) were needed to enhance hyperactivation of sperm in the fertile population. In the latter, extended contact with the ionophore induced no significant change compared to a 30-min incubation period. Since this type of movement is an essential feature of the fertilizing gamete, a low hyperactivation rate may partly explain fertilization failure in the asthenozoospermic group.