Evaluation of three different extenders for use in emergency salvaging of epididymal spermatozoa from a Cantabric brown bear.
The Cantabrian brown bear (Ursus arctos) constitutes an endangered subpopulation of the European brown bear in the north of Spain. We have carried out a post-mortem recovery of epididymal spermatozoa from a Cantabrian brown bear (7 years old, 170 kg; 30 min post-mortem), cryopreserving those recovered from the cauda epididymis (929 × 10(6) spermatozoa, 54% motile, 82% cytoplasmic droplets). For freezing, three extenders based on Test-Tris-Fructose + 4% glycerol were used: (1) 325 mOsm/kg and 10% egg yolk; (2) 430 mOsm/kg and 15% egg yolk; (3) 300 mOsm/kg, Equex-EDTA and 20% egg yolk. After thawing, we obtained higher motility for extender 3 (31%), but extender 2 yielded the highest viability (66.9%) and mitochondrial activity (67.1%). Caffeine stimulation showed that extender two rendered the highest recovery values of post-thawing motility with respect to the fresh sample. In conclusion, epididymal spermatozoa of brown bear can be frozen applying an extender with osmolality similar to epididymal environment.
Anel
L
L
ITRA-ULE, INDEGSAL, León, Spain. laner@unileon.es
Alvarez
M
M
Anel
E
E
Martinez-Pastor
F
F
Martinez
F
F
Chamorro
C
C
de Paz
P
P
D000818:Animals; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary; D003451:Cryoprotective Agents / Q000737:chemistry; D056727:Endangered Species; D004822:Epididymis / Q000166:cytology*; D006358:Hot Temperature; D008297:Male; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013030:Spain; D013076:Sperm Count / Q000662:veterinary; D013094:Spermatozoa / Q000502:physiology*; D020858:Tissue and Organ Harvesting / Q000662:veterinary; D001503:Ursidae
D003451:Cryoprotective Agents