Comparative study of the kinetics of the acrosome reaction and survival of human spermatozoa in various media.

The in-vitro kinetics of the acrosome reaction and the survival of human spermatozoa were studied under different capacitating conditions. Human preovulatory follicular fluid (FF), isotonic BWW (N-BWW) and hypertonic BWW (H-BWW) were tested. Motile sperm selected by migration in these media were examined after 1, 3, 5 and 22 h of incubation under 5% CO2. The kinetics of the reaction in the population of live, morphologically normal sperm was dependent on both the culture medium and time of incubation. In the first hour, the mean percentage of acrosome-reacted sperm in H-BWW and FF was significantly greater than in N-BWW. The proportion of reacted cells increased significantly after 3 h in N-BWW (P = 0.001), after 5 h in FF (P = 0.03) and after 22 h in H-BWW (P = 0.01). A significant decrease in sperm viability was registered at 3 and 22 h of incubation (P less than 0.002) in all media. These results demonstrate that both H-BWW and FF stimulate the acrosome reaction while survival is optimal in the latter.