Pentoxifylline induces capacitation and acrosome reaction and improves quality of motility in canine ejaculated spermatozoa.

To evaluate effects of different concentrations of pentoxifylline, as phosphodiesterase inhibitor, on quality of motility, capacitation and acrosome reaction, Ejaculated spermatozoa were collected from crossbred dogs. The sperm were incubated at concentrations of 0.1, 1, 10 and 100mM pentoxifylline for 2h. Conventional assessment was also made on the percentage of motility and quality of motility of spermatozoa; values were expressed as sperm motility index (SMI). Capacitation and acrosome reaction were also evaluated by chlortetracycline fluorescence staining. SMI as quality index of sperm was significantly increased in concentrations of 10 and 100mM pentoxifylline during 1 and 2h compared to control. The number of capacitated or acrosome reacted spermatozoa significantly (P<0.05) were higher than controls at high concentrations of pentoxifylline (10 and 100mM) during 1 and 2h. In conclusion, high concentration of pentoxifylline is able to induce capacitation and acrosome reaction and improves quality of motility in canine ejaculated spermatozoa.