Platelet-activating factor acetylhydrolase activity affects sperm motility and serves as a decapacitation factor

To determine the relationship between platelet-activating factor acetylhydrolase (PAFah) content in semen and sperm motility.

The PAFah levels in semen were measured and correlated with sperm motility.

Clinical laboratory in a private assistant reproductive technology clinic.

Three hundred and twelve men seeking diagnosis and treatment of infertility.

Semen samples were collected from 312 healthy mature men seeking infertility treatment. Sperm motility and PAFah activity were measured in seminal plasma. Data was analyzed by Student's t test and regression analysis.

PAFah activity and sperm motility.

Seminal PAFah content ranged from a low of 179 IU/L to a high of 2,457 IU/L. The overall mean PAFah content in semen was 780.59 IU/L. Linear regression analysis revealed a significant (R2 = 0.655) and negative relationship between PAFah content in semen and sperm motility. Semen specimens with high percent motility (> or = 50%) had significantly lower PAFah concentrations (442.03 +/- 14.37 IU/L) than those with the lower percent sperm motility (< 50%) (882.16 +/- 18.45 IU/L).

The data confirm the presence of PAFah in human semen and that activity is significantly and negatively correlated with sperm motility. The PAFah is proven to be a candidate for sperm decapacitation factors, whereas PAF is qualified to be a candidate for sperm capacitation factors.