The impact of epididymal and accessory sex gland function on sperm motility.

BACKGROUND Little is known about the regulation of sperm motility, which is an important predictor of male fertility. However, both testicular and post-testicular factors may be involved, although the impact of the latter has been relatively poorly investigated. METHODS In semen samples from 301 young men from the general Swedish population (mean +/- SD age 18.2 +/- 0.4 years), we assessed sperm motility by use of a manual method as well as computer-assisted sperm analysis (CASA) and correlated these values to seminal levels of neutral alpha-glucosidase (NAG), prostate-specific antigen (PSA), zinc and fructose. RESULTS There were significant positive correlations between seminal levels of NAG, and PSA and CASA percentage motile sperm (r = 0.158, P = 0.009; r = 0.155, P = 0.01 respectively), and significant negative correlations with CASA percentage immotile sperm (r = -0.206, P = 0.001; r = -0.157, P = 0.009 respectively). In a multiple regression analysis it was found that, apart from sperm concentration, the level of PSA was the most significant and independent parameter in predicting percentage motile sperm (beta = 0.220, P = 0.037). CONCLUSION Our study demonstrated the regulatory effect of post-testicular glands on the motility of sperm. This is to our knowledge the first study showing a direct correlation between the seminal PSA levels and sperm motility in a group of men representing the general population. In future investigations and searches for specific treatment modalities in male infertility, more attention should be paid to the epididymis and accessory sex gland function.