Variability in sperm penetration rate in the hamster oocyte penetration test in healthy young men ii
Japanese Journal of Fertility and Sterility 37(3): 451-457
Nine healthy young donors were subjects of the present study. A total of 59 semen samples were obtained over one and half years. The number of semen samples was 8 in one donor, 7 in 3 donors and 6 in 5 donors. Semen analysis (sperm concentration, sperm motility, volume and morphology) and hamster oocyte penetration tests (hamster tests) using spermatozoa treated with or without Ca ionophore A23187 were performed simultaneously. The variation of sperm penetration rate (SPR) in the hamster test in a donor (maximum SPR-minimum SPR) ranged from 7 to 64% and from 16 to 70% from ionophore treated and untreated spermatozoa, respectively. There was no significant difference between the variation of SPR in ionophore treated spermatozoa and untreated spermatozoa. Statistical analysis revealed no correlation between the SPR and semen parameters, and that the SPR was not influenced by technical factors. These results indicate that SPR in healthy men varies considerably over one and half years and that the variation may reflect temporal changes in the fertilizing ability of spermatozoa.