Cholesterol efflux from sperm: approaches and applications

Following ejaculation, sperm appear morphologically mature, but functionally they are inactive. To attain functional capability or capacitation in vivo, sperm must reside in the female reproductive tract for a certain period of time before fertilization. In the female reproductive tract, cholesterol efflux from the sperm plasma membrane is considered vital for the initiation of capacitation. A number of in vitro studies have used biological and nonphysiological means to understand the phenomenon of cholesterol efflux and capacitation. In this review, we present a short overview of the role of cholesterol efflux in regulating sperm capacitation using various agents. This review provides insight to researchers designing new procedures for sperm preparation to be used in assisted reproductive technology.