Asian Journal of Andrology | 2019
Influence of in vitro capacitation time on structural and functional human sperm parameters
Abstract
A cascade of dramatic physiological events is linked to the sperm acrosome reaction and binding to the oocyte s zona pellucida during human sperm capacitation. However, structural and functional sperm changes during capacitation currently remain poorly defined. Here, we performed a multibiomarker approach based on the utilization of sperm concentration, motility, viability, morphology, acrosome reaction, tyrosine phosphorylation, DNA fragmentation, and lectin-binding sites to analyze the impact caused by swim-up selection times (uncapacitated, 1 h capacitated, and 4 h capacitated) on sperm function and structure in normozoospermic samples. We found that a 4 h swim-up capacitation increased sperm quality, because a large number of cells with normal morphology and lower DNA fragmentation rates were recovered. Furthermore, the long-term capacitation induced a higher percentage of cells with tyrosine phosphorylation of the principal piece as well as a redistribution of lectin-binding sites. Overall, the multivariate biomarkers analyzed showed a less variable distribution on spermatozoa recovered after 4 h capacitation than that with the shorter capacitation time. These findings stress the importance of capacitation time as a relevant factor in sperm quality with potential biological reproductive implications both for basic research and in assisted reproduction techniques.