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

Objective: To determine the relationship between platelet-activating factor acetylhydrolase (PAFah) content in semen and sperm motility. Design: The PAFah levels in semen were measured and correlated with sperm motility. Setting: Clinical laboratory in a private assistant reproductive technology clinic. Patient(s): Three hundred and twelve men seeking diagnosis and treatment of infertility. Intervention(s): 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. Main Outcome Measure(s): PAFah activity and sperm motility. Result(s): Seminal PAFah content ranged from a low of 179 IU/L to a high of 27457 IU/L. The overall mean PAFah content in semen was 780.59 IU/L. Linear regression analysis revealed a significant (R-2 = 0.655) and negative relationship between PAFah content in semen and sperm motility. Semen specimens with high percent motility (>= 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). Conclusion(s): 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.