[Why and how to ameliorate capacitation without inducing an acrosome reaction?].

During their travel through the feminine genital tract, spermatozoa undergo a continuous, reversible and non specific maturation called "capacitation". Capacitation allows the ability to bind to the zona pellucida and to start acrosome reaction after induction. Capacitation is associated with biochemical modifications of the membrane and the cytoplasma. To fertilize oocytes, spermatozoa must first become capacitated, change their motility to an hyperactivated pattern, without undergoing a premature, spontaneous acrosome reaction. In vitro, follicular fluid, progesterone, pentoxifylline and adenosine analogues have been shown to improve capacitation without inducing acrosome reaction in case of male infertility.