Effects of fenvalerate and cypermethrin on rat sperm motility patterns in vitro as measured by computer-assisted sperm analysis.

Fenvalerate and cypermethrin were reported to impair male reproductive function, inducing significant reductions in epididymal sperm count. Further, fenvalerate was shown to reduce sperm motility. However, it is not clear whether fenvalerate and cypermethrin might impact sperm motility directly or indirectly by affecting spermatogenesis via interaction with androgens or their receptors. In this study, sperm suspensions were treated with fenvalerate and cypermethrin, respectively, at various concentrations (0, 1, 4, 16, or 64 micromol/L) for various times (1, 2, or 4 h). The motility parameters of sperm treated with these two insecticides were analyzed with a computer-assisted sperm analysis (CASA) system. The differential effects of fenvalerate and cypermethrin on rat sperm motility patterns in vitro were also compared. Our study revealed that fenvalerate and cypermethrin reduced sperm motility in vitro in a concentration- and time-dependent manner. Cypermethrin exerted a greater effect on sperm motility in comparison to fenvalerate. These results provided evidence that fenvalerate and cypermethrin directly influence mature rat sperm motility.