Changes in Motility Parameters of Mouse Spermatozoa in Response to Different Doses of Progesterone during Course of Hyperactivation

The aim of this study was to evaluate changes that occur in motility parameters of progesterone treated mouse spermatozoa during course of hyperactivation. Mouse spermatozoa treated with different doses of progesterone were videotaped after 10 min and 90 min of incubation. For each sperm, one second of movement of the head-midpiece junction was traced from the videotape and for each tracing seven motility parameters were studied using computer assisted image analysis. For all progesterone treated spermatozoa, motility rate differed significantly from control group after 90 min of incubation. Motility parameters for high doses of progesterone 10 and 100 µg/ml showed hyperactivation occurred during 10 min of incubation. With treatment of 1 µg/ml progesterone, hyperactivated motility pattern of spermatozoa occurred 90 min after incubation similar to the control group showing that low dose of progesterone is unable to induce hyperactivation. In conclusion, progesterone induces hyperactivation in mouse sperm and reduces the motility rate during the time