Abstract: Various trations of PI(0, 0.5, 1.0and2.0mg/ml) were incubated with super-activated human spermatozoa at37 ºC for 5, 15 and 30min, then the vitality and motility of spermatozoa were examined, respectively, after which the washed spermatozoa were cultured with zone-free superovulated hamster ova for 3h. Observations were made for the presence of fertilized ova, ova attached-spermatozoa and pronuclei. The results showed that the vitality and III grade forward motility of spermatozoa were significantly reduced (P<0.05) after drug treament. There was a good negative relativity between vitality, motility and time, dose of PI treatment (P<0.05). The fertilization rate and mean attached spermatozoa/ova, the index of fertilization, were significantly reduced (P<0.01) as compared with controls. There was no pronuclei formation in the drug treated groups. It is suggested that PI may inhibit the ability of fertilization of human spermatozoa and the effect is expressed in several aspects.

Key words: Pentamidine Isethionate (PI), Human spermatozoa, Motility ability, Fertilizing ability