Metal chelators change the human sperm motility pattern.

OBJECTIVE: To investigate the influence of zinc on the generation of motility.
DESIGN: Prospective study. SETTINGS: Outpatient clinic of the Center of Dermatology and Andrology. PATIENT(S): Seventy-three patients and 10 sperm donors. INTERVENTION(S): Motile spermatozoa were isolated by swim-up and incubated for 1, 2, 4 or 6 hours with DL-penicillamine, 2,3-dimercaptopropan-1-sulfonate, and meso-2,3-dimercapto-succinimic acid at concentrations of 1, 10, and 100 micro mol/L. MAIN OUTCOME MEASURE(S): Motility was analyzed by means of computer-assisted semen analysis (CASA). RESULT(S): Significant dose-dependent changes in nonlinear motility, progressive motility, and velocity straight line (VSL) were observed. After only 1 hour of incubation, nonlinear motility decreased, and progressive motility and VSL increased. The percentage of immotile spermatozoa was not affected. Time-dependent changes in motility were observed on a significantly higher or lower level as compared to the control. Comparing the chelators after 2 hours revealed that DL-penicillamine showed the strongest effect on the sperm. CONCLUSION(S): The results imply that chelators can eliminate at least some part of the zinc from the flagellum. This zinc elimination appears to lead to comparable changes of the outer dense fibers as seen in vivo during epididymal maturation, finally resulting in improved motility.