STIMULATION OF CRYOPRESERVED EPIDIDYMAL SPERMATOZOA OF THE DOMESTIC CAT USING THE MOTILITY STIMULANTS CAFFEINE, PENTOXIFYLLINE, AND 2'-DEOXYADENOSINE

We have investigated the effects of caffeine, pentoxifylline, and 2'-d eoxyadenosine on the motion characteristics and longevity of domestic cat spermatozoa. Freshly collected or cryopreserved domestic cat epidi dymal sperm were incubated with 0.01-20 mM caffeine, pentoxifylline, o r 2'-deoxyadenosine for 15 minutes at 23 degrees C. The percent motili ty (MOT), curvilinear velocity (VCL), linearity (LIN), straight line v elocity (VSL), and amplitude of lateral head displacement (ALH) were d etermined for each group using computer-assisted semen analysis. Fresh ly collected domestic cat sperm exhibited a strong forward progressive movement, and treatment with caffeine, pentoxifylline, or 2'-deoxyade nosine did not consistently alter sperm motion. Following cryopreserva tion, spermatozoa exhibited decreased (P < 0.05) MOT, VCL, VSL, and AL H. Caffeine and pentoxifylline increased (P < 0.05) the MOT, VSL, VCL, and ALH of cryopreserved sperm at 0.01-20 mM, in a dose-dependent man ner. 2'-Deoxyadenosine also increased (P < 0.05) both VSL and VCL at 1 .0 mM, and MOT, VSL, VCL, and ALH at 10 mM. All treatments shifted the percentage of nonhyperactive sperm to either a transitional or hypera ctivated state. The motility indices of cryopreserved samples were exa mined during a 6- hour incubation to assess the effects of caffeine, p entoxifylline, and 2'-deoxyadenosine on sperm longevity. Compared to u ntreated control samples, the longevity of stimulated cryopreserved sp erm was not reduced. These results indicate that motility stimulants m ay prove useful for enhancing the fertility of cryopreserved cat sperm by increasing their motility and producing hyperactivated motion.