Determination of sperm acrosin activity for evaluation of male fertility

Aim: To investigate a simple method for assaying acrosin activity for the evaluation of male fertility. Methods: The acrosin activity of 7.5 × 10^6 sperm without seminal plasma and acrosin activity inhibitors was assayed using N-α-benzoyl-DL-arginine-p-nitroanilide (BAPNA) and detergent (Triton X-100) as substrate. Results: The acrosin activity of 60 normal fertile men (35±10μIU/10^6 sperm ) was higher than that of 168 infertile men ( 16±8μIU/10^6 sperm) (P < 0.01 ). It was indicated that there was a significant positive correlation between the acrosin activity and the sperm motility ( r≥0. 6534, P < 0.01 ) and a significant negative correlation between the sperm malformed rate and the WBC number ( r≤-0. 5426, P < 0.01 ). The temperature and time of incubation and the sperm concentration could influence the assay results. Conclusion: Acrosin activity is an important index for the evaluation of male fertility. The approach developed by the authors is a simple method for the determination of acrosin activity.