Short-term preservation of fowl sperm in buffered potassium chloride

Abstract

Previous research demonstrated that sperm motility is dependent upon mitochondrial calcium cycling. Thus, sperm are inactivated when extracellular calcium ions are chelated. Mitochondrial calcium cycling, however, is driven by extracellular sodium ions. The hypothesis that sperm inactivation is subject to 2 variables was tested in the present work. Sperm motility was evaluated with computer-assisted sperm motion analysis in the first experiment. Sperm became immotile within minutes when suspended in buffered isotonic potassium chloride containing calcium ions. This outcome set the stage for the second experiment in which sperm were inactivated by centrifugation through 12% (wt/vol) Accudenz prepared with potassium chloride and tetrasodium 1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA). Sperm mobility was the end point in the second and subsequent experiments. Potassium chloride was a suitable medium in regard to sperm inactivation with BAPTA followed by storage for 2 h at 10°C. Consequently, sperm so inactivated were reactivated after 1, 2, 3, 4, and 5 h of storage in the third experiment. Whereas pre-and postwash sperm mobility were equivalent, sperm mobility declined with time (P < 0.001) without exogenous energy in the storage medium. Therefore, the effect of 5 mM glucose was tested in the fourth experiment. In this case, recovery of sperm mobility was independent of time when sperm were stored at 10°C for 5 h (P > 0.05). Potassium chloride was replaced with potassium glutamate in the last experiment. Whereas reactivation was once again independent of time when sperm were stored with glucose (P > 0.05), greater variability was observed among observations in comparison with the potassium chloride-based medium. In summary, sperm motility was inactivated when calcium was chelated and extracellular sodium was replaced with potassium. Sperm reactivation was most consistent when chloride was the predominant extracellular anion. Collectively, these experiments demonstrate that short-term sperm storage can be achieved with simple media that promote sperm glycolysis and minimize energy demands imposed by the active transport of calcium and sodium ions.

Evaluation of two diluents for the storage of fresh and cryopreserved semen of Harris hawk (Parabuteo unicinctus)

“…The motility in both diluents was also significantly lower post-thawing (P<0.05) than in the fresh condition. The results obtained in this study during the basic sperm evaluation demonstrated that the cryopreservation process affects sperm motility, resulting in a 50% decrease in both diluents; these data are consistent with reports by other authors (Herrera et al 2005, Froman 2013), who report that motility is the only parameter in the basic evaluation of sperm that is affected by the process of freezing bird sperm. The percentage of live sperm did not differ (P>0.05) between the BPSE and Lake diluents, and in fresh (98.0±0.2 and 96.0±1.0) and thawed (95.0±0.5 and 94.0±0.5) semen.…”

Evaluation of a semen extender from a bioenergetic perspective1

“…This conclusion is valid because fowl sperm propulsion, as measured by either the sperm mobility assay or computer-assisted sperm motion analysis, is absolutely dependent on mitochondrial Ca 2+ cycling. This phenomenon serves to activate phospholipase A2 and thereby provide endogenous long-chain fatty acids for β-oxidation (Froman, 2003(Froman, , 2013Feltmann, 2005, 2010;Froman et al, 2006). In other words, when sperm mitochondria are functional, they then respond to the experimental conditions used.…”