fa Morphometry Morphometry Original Original <strong>Purpose</strong>: To evaluate the changes that occur in the motility parameters of progesterone treated sperms during the course of hyperactivation.<br> <strong>Materials and Methods</strong>: Spermatozoa treated with different doses of progesterone were videotaped after 10 min and 90 min. For each sperm, 1 sec. of movement of the head-midpiece junction was traced from the videotape. For each tracing, seven motility parameters were studied using computer assisted image analysis.<br> <strong>Results</strong>: For all the progesterone treated spermatozoa, motility rates differed significantly from that of the control group after 90 occurred during 10 min. of incubation. With treatment of 1mg/ml progesterone, the hyperactivated motility pattern of spermatozoa occurred 90 min. after incubation similar to that in the control group, showing that a low dose of progesterone is unable to induce hyperactivation.<br> <strong>Conclusion</strong>: Progesterone induces hyperactivation in mouse sperm and reduces the motility rate during the time. Progesterone, Hyperactivation, Spermatozoa, Mouse 13 21 http://anatomyjournal.ir/browse.php?a_code=A-10-304-70&slc_lang=fa&sid=1 Majid Katebi 10031947532846006799 10031947532846006799 No Mansoureh Movahedin 10031947532846006800 10031947532846006800 Yes Mir Abbas Abdol Vahabi 10031947532846006801 10031947532846006801 No Mohammad Akbari 10031947532846006802 10031947532846006802 No Farid Abolhasani 10031947532846006803 10031947532846006803 No Ali Sobhani 10031947532846006804 10031947532846006804 No