The in vitro effect of benzo[a]pyrene on human sperm hyperactivation and acrosome reaction

Objective To evaluate the in vitro effect of benzo[a]pyrene on sperm hyperactivation and acrosome status in normozoospermic semen samples of nonsmokers analyzed by computer-assisted semen analysis (CASA). Design Experimental in vitro study. Setting Andrology laboratory. Patient(s) Thirteen proven fertile, normozoospermic, and nonsmoking men. Intervention(s) Spermatozoa were washed free of seminal plasma and were treated with different concentrations of benzo[a]pyrene and compared with controls treated with medium alone. The benzo[a]pyrene concentrations were: 100, 50, 25, and 12.5 μg/mL. Main Outcome Measure(s) Effect of varying concentrations of benzo[a]pyrene on sperm hyperactivation and acrosomal reaction. Result(s) A statistically significant increase in sperm hyperactivation was observed in presence of benzo[a]pyrene at concentrations of ≥50 μg/mL. The result of the acrosome halo test showed that concentrations of benzo[a]pyrene ≥25 μg/mL statistically significantly decreased the percentage of halo formation, indicating an inappropriate (false) acrosome reaction. Conclusion(s) Benzo[a]pyrene statistically significantly affected sperm functional competence as evidenced by increased hyperactivation as well as premature acrosomal reaction.