In vitro effects of pentoxifylline on kinematic parameters, capacitation, and acrosome reaction of ram epididymal sperm

To evaluate effects of different concentrations of pentoxifylline, as phosphodiesterase inhibitor, on kinematic parameters, capacitation, and acrosome reaction, spermatozoa were separated from ram caudal epididymis. Epididymal sperm were incubated at concentrations of 0. 01 mM, 0. 1 mM, 1 mM, and 10 mM pentoxifylline for 60 min. Motion parameters were assessed using the CASA system. Capacitation and acrosome reaction were also evaluated by CTC staining. Pentoxifylline at 0. 01 mM appeared significant (P < 0. 05) in increasing progressive motility, straight line velocity (VSL), VCL, average path velocity (VAP), average amplitude of lateral head displacement in micrometers (ALH), and mean angular displacement (MAD) and significant (P < 0. 05) in decreasing BCF in spermatozoa compared with controls. Pentoxifylline at 10 mM caused a significant (P < 0. 05) decrease in progressive motility, VSL, VAP, ALH, LIN, and WOB compared with controls. There was a significant (P < 0. 05) reduction in uncapacitated spermatozoa but an insignificant rise in capacitated and acrosome-reacted spermatozoa in 0. 01 mM pentoxifylline when compared with controls. Capacitated spermatozoa were significantly (P < 0. 05) lower in 0. 1 mM pentoxifylline, whereas capacitated and acrosome-reacted spermatozoa were insignificantly higher than controls. In 10 mM pentoxifylline, significant increase was observed in capacitated and significant decrease in acrosome-reacted spermatozoa. In conclusion, a low concentration of pentoxifylline was able to increase most kinematic parameters while high concentration had the opposite effect. Pentoxifylline in high concentration increased capacitation but decreased acrosome reaction. © 2009 Springer-Verlag London Limited.