Effects of pentoxifylline on sperm motility and hyperactivation in normozoospermic and normokinetic semen

To determine the effects of in vitro incubation with pentoxifylline on sperm motion characteristics of spermatozoa from normozoospermic, normokinetic specimens.

Prospective, controlled experiment.

Andrology laboratory, university-based fertility center.

Healthy, untreated male partners of couples attending the fertility center.

Each specimen was washed, pelleted by centrifugation, then resuspended in human tubal fluid medium (HTF). Two portions were incubated at 37 degrees C, one with pentoxifylline (final concentration = 1 mg/mL = 3.6 mM) and the other without pentoxifylline (control). After 1 hour, the pentoxifylline-treated portion was divided: one half was washed to remove pentoxifylline, then further incubated in HTF; the other half remained incubated in HTF with pentoxifylline.

Motility, hyperactivation, amplitude of lateral head displacement (ALH), curvilinear velocity (VCL), straight line velocity (VSL), linearity (LIN), beat-cross frequency.

Incubation with pentoxifylline did not increase motility, VSL, LIN, or beat-cross frequency but did significantly increase HA, VCL, and ALH at 1, 2, and 4 hours, compared with control. Incubation in control medium without pentoxifylline did not significantly increase any of the parameters measured. After 24 hours of incubation with or without pentoxifylline, all parameters measured were significantly decreased, with the exception of LIN.

Pentoxifylline does not increase percentage motility of washed spermatozoa in capacitation medium. Enhancement of sperm HA by pentoxifylline in capacitation medium occurs with normozoospermic, normokinetic semen specimens. This effect persists for up to 4 hours when pentoxifylline is removed from the medium after 1 hour of incubation.