Hyperactivation of capacitated human sperm correlates with the zona pellucida-induced acrosome reaction of zona pellucida-bound sperm

Abstract

BACKGROUND: The aim of this study was to determine the relationship between human sperm hyperactivation (HA), sperm-zona pellucida (ZP) binding and the ZP-induced acrosome reaction (AR) of ZP-bound sperm in vitro. METHODS: Sperm samples from 129 infertile men were studied. Motile sperm (2 x 10(6)) selected by Pure sperm were incubated with four oocytes in 1 ml human tubal fluid supplemented with 10% human serum. After 2-h incubation, the number of sperm bound to the ZP and the AR of ZP-bound sperm were examined. Velocities and HA of sperm in insemination medium were assessed by Hamilton-Thorn Sperm Analyzer. RESULTS: The HA was highly correlated with the ZP-induced AR in all the subjects (rh..