Electroejaculated baboon (Papio anubis) sperm requires a higher dosage of pentoxifylline to enhance motility

Sperm collected by electroejaculation often show poor motility. The objective was to determine whether the addition of the phosphodiesterase inhibitor, pentoxifylline, would stimulate electroejaculated baboon sperm motility.

Electroejaculation was performed on several occasions on a male baboon and sperm collected after familiarization. Pentoxifylline was tested at the standard concentration (1 mg/ml) and at twice the concentration. Sperm parameters were evaluated using a sperm motility analyzer, as well as acrosome and DNA integrity techniques.

Sperm exposed to 2 mg/ml pentoxifylline had higher total motility when compared with the control and 1 mg/ml treatment. Rapid progression and velocities were higher after pentoxifylline. The acridine orange DNA normality test showed that over 90% of collected sperm had intact unfragmented DNA. About half the sperm population had normal morphology and intact acrosomes. A low percentage had cytoplasmic droplets.

Sperm collected by rectal probe electroejaculation required a higher concentration (2 mg/ml) of pentoxifylline for enhanced total motility, rapid progression, and higher velocity. This suggested differences in membrane properties or phosphodisterase activity in electrojeaculated sperm. The electroejaculation procedure did not denature sperm DNA at the acridine orange assay level nor were the acrosomes disrupted. The present study also documented unique information on baboon kinematic parameters.