Effect of pentoxifylline on motility and longevity of fresh and thawed dog spermatozoa

The effect of pentoxifylline on fresh and frozen-thawed dog spermatozoa was evaluated. In Expt 1, 0.0036 mol l-1 or 0.0072 mol l-1 pentoxifylline was added to fresh dog spermatozoa. Semen was incubated at 25 degrees C or 39 degrees C. In Expt 2, pentoxifylline was added either before freezing or in the process of thawing at a final concentration of 0.0072 mol l-1. Addition of pentoxifylline significantly increased the percentage of progressively motile spermatozoa in fresh semen. The most beneficial effect of pentoxifylline on frozen-thawed semen was observed (P < 0.001) when it was added to semen in the process of thawing.