Effect of post-thaw dilution with caffeine, pentoxifylline, 2'-deoxyadenosine and prostatic fluid on motility of frozen-thawed dog semen.

The aim of the experiment was to evaluate the motility pattern of frozen-thawed canine semen to which pentoxifyilline (PTX), caffeine (CAF), 2'-deoxyadenosine (DX), and prostatic fluid (PROST) were added after thawing. Semen evaluations were performed using computer-assisted sperm analysis (CASA) at thawing and during 120min of incubation at 37 degrees C. Three experiments were conducted: 1) to establish which concentrations of stimulants work best; 2) to investigate the interaction between thawing rate and addition of CAF 5mM, PTX 2.5mM and PROST; 3) to evaluate the effect of PTX 7.5mM and DX 5mM on semen motility after thawing. In experiment 1, ALH and VCL were enhanced at thawing by CAF 7.5mM (CAF 7.5: 9.1+/-0.5microm; control: 6.7+/-0.4microm) and DX 5 and 7.5mM (DX 5: 199.1+/-12.8microm/s; DX 7.5: 197.3+/-13.9microm/s; control: 162.5+/-8.4microm/s), while PTX 2.5-5-7.5mM improved TOT after 120min of incubation. In experiment 2, PROST lowered ALH values throughout incubation (P<0.05) with respect to the other treatments, in particular when compared to CAF at Time=30 and at Time=60. In experiment 3, PTX 7.5mM improved VAP (PTX: 101.6+/-6.8microm/s; control: 81.9+/-10.5microm/s), VSL (PTX: 82.9+/-6.4microm/s; control: 65.9+/-9.8microm/s), VCL (PTX: 214.3+/-13.3microm/s; control:167+/-15.7microm/s), ALH (PTX: 10.5+/-0.3; control: 7.3+/-1.4microm), PM (PTX: 11.3+/-4.2%; control: 7.7+/-3.9%) and TOT (PTX: 20.1+/-5.3%; control:15.6+/-5.6%) at Time=120, while DX 5mM influenced VCL at Time=60 (DX: 218.3+/-14.3microm/s; control: 188.5+/-7.5microm/s, P<0.05). Motility stimulants may be useful for enhancing motility of canine frozen-thawed spermatozoa without affecting sperm longevity.