ASSESSMENT OF HYPERACTIVATION, ACROSOME REACTION AND MOTILITY CHARACTERISTICS OF SPERMATOZOA FROM SEMEN OF MEN OF PROVEN FERTILITY AND UNEXPLAINED INFERTILITY

Semen from men of proven fertility was compared with that of men with unexplained infertility to determine differences in spermatozoal funct ions such as hyperactivation and acrosome reaction and spermatozoal mo tility characteristics. The hyperactivated spermatozoa in both groups could be visualised on the monitor of the Computer Assisted Semen Anal yser and they exhibited 'circling', 'thrashing', 'starspin' and 'helic al' motility patterns and the mean hyperactivation rates were not sign ificantly different. However, 20% of the men with unexplained infertil ity did not exhibit hyperactivation compared to only 4% in the fertile group. Furthermore, the semen from infertile men when evaluated for h yperactivation could be categorised into two groups with those having lower hyperactivation (<10% or <6% after 4 and 6 h of incubation respe ctively), forming the first group, and those having a higher hyperacti vation rate constituting the second group. In the fertile men such dis tinct groups were not visible and the percentage hyperactivation range d from 1 to 16%. No significant differences were observed in the rate of acrosome reaction of fertile and unexplained infertile men. The non -hyperactivated spermatozoa from unexplained infertile men showed a si gnificant increase in path velocity (VAP), curvilinear velocity (VCL) and amplitude of lateral head displacement (ALH) and a decrease in lin earity (LIN) and straightness (STR) compared to spermatozoa from ferti le men. Furthermore, the hyperactivated spermatozoa from infertile men also showed an increase in progressive velocity (VSL) (only after 2 h of incubation) and LIN and decrease in ALH and beat cross frequency ( BCF) compared to spermatozoa from fertile men. The results are discuss ed in the light of the importance of the above spermatozoal functions and spermatozoal parameters in fertilization.