IN-VITRO FERTILIZATION AND THE EFFECT OF PROGESTERONE AND 17-ALPHA-HYDROXYPROGESTERONE ON ACROSOME REACTION OF MOUSE EPIDIDYMAL SPERMATOZOA

This study assessed the effect of progesterone and 17 alpha-hydroxypro gesterone (17 alpha-OH-progesterone) at concentrations of 0.01-10 mu g /ml, on the acrosome reaction and in vitro fertilizing ability of mous e epididymal spermatozoa. Cumulus masses containing oocytes were cultu red in Brinster's medium, to which were added capacitated epididymal s permatozoa which had been incubated in medium with various concentrati ons of progesterone or 17 alpha-OH-progesterone for 90 min. IVF succes s rate was assessed 20-24 h following insemination. Progesterone was f ound to increase the fertilization rate at the 1 mu g/ml and 10 mu g/m l concentrations while lower concentrations had no effect. However, 17 alpha-OH-progesterone failed to show any effect on fertilizing abilit y. Incubation of epididymal spermatozoa in medium containing 1 mu g/ml and 10 mu g/ml progesterone significantly increased the acrosome reac tion as monitored by a chlortetracycline fluorescence assay. 17 alpha- OH-progesterone, however, failed to show any effect on the acrosome re action. The results suggest direct effects of progesterone, but not of 17 alpha-OH-progesterone, on fertilization and the acrosome reaction of mouse spermatozoa.