Acta Vet. Brno 2014, 83: 19-25

Effect of caffeine on functions of cooling-stored ram sperm in vitro

Eliška Špaleková1, Alexander V. Makarevich1, Elena Kubovičová1, Alexander Ostró2, Peter Chrenek1,3

1Animal Production Research Centre Nitra, Slovak Republic
2P. J. Šafárik University in Košice, Faculty of Medicine, Slovak Republic
3Slovak University of Agriculture in Nitra, Department of Biochemistry and Biotechnology, Slovak Republic

Caffeine is a well-known sperm motility stimulator, however, its effects on cooling-stored ram semen are unknown. The aim of the study was to examine the effect of caffeine on selected motility and viability indices of cooling-stored ram spermatozoa. Sperm ejaculates from 4 rams were diluted (1:3) in a Triladyl extender. Samples were stored for 96 h at 4-5 °C in two sets. In the first set used for motility analysis, caffeine at concentrations of 1, 2 or 4 mmol·l-1 was added to sperm aliquots on the day of analysis. In the second set used for viability assay, caffeine at the same concentrations (1, 2 or 4 mmol·l-1) was added at the beginning of storage. Control was left without caffeine addition. Sperm motility was analyzed at 0, 24, 48 and 72 h of cooling-storage. Viability assays were done after 72–96 h of cooling-storage. Caffeine significantly (P < 0.05) increased sperm motility and progressive movement and maintained this value for 72 h. Caffeine at the dose of 2 mmol·l-1 and 4 mmol·l-1 significantly (P < 0.05) reduced the proportion of dead/necrotic sperm detected by propidium iodide and proportion of apoptotic sperm detected by Yo-Pro-1, respectively. No effect of caffeine on plasma membrane integrity was noted. Proportion of sperm with membrane destabilization (annexin V-Fluos) was reduced by caffeine given at 1 and 4 mmol·l-1 compared to control. Our study for the first time demonstrates that caffeine maintains motility and viability of cooling-stored ram sperm for longer time compared to control.


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