Use of hypometabolic TRIS extenders and high cooling rate refrigeration for cryopreservation of stallion sperm: Presence and sensitivity of 5′ AMP-activated protein kinase (AMPK)

Use of hypometabolic TRIS extenders and high cooling rate refrigeration for cryopreservation of stallion sperm: Presence and sensitivity of 5′ AMP-activated protein kinase (AMPK)

Alex Córdova, Pablo Strobel, Andrés Vallejo, Pamela Valenzuela, Omar Ulloa, Rafael A. Burgos, Bruno Menarim, Joan Enric Rodríguez-Gil, Marcelo Ratto, Alfredo Ramírez-Reveco

Instituto de Ciencia Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Chile; Instituto de Ciencias Clínicas, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Chile; Instituto de Farmacología y Morfofisiología, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Chile; Haras Militar Pupunahue, DGFER-Ejército de Chile, Chile; Unitat Reproducció Animal, Universitat Autònoma de Barcelona, Spain; Ross University School of Veterinary Medicine, Basseterre, West Indies

This study evaluated the effect of the use of hypometabolic TRIS extenders in the presence or the absence of AMPK activators as well as the utilization of high cooling rates in the refrigeration step on the freezability of stallion sperm. Twelve ejaculates were cryopreserved using Botucrio® as a control extender and a basic TRIS extender (HM-0) separately supplemented with 10 mM metformin, 2 mM 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR), 2 mM Adenosine monophosphate (AMP), 40 μM compound C AMPK inhibitor or 2 mM AMP + 40 μM compound C. Our results showed that the utilization of a hypometabolic TRIS extender supplemented or not with AMP or metformin significantly improves stallion sperm freezability when compared with a commercial extender. Additionally, high cooling rates do not affect stallion sperm quality after cooling and post-thawing. Finally, stallion spermatozoa present several putative AMPK sperm isoforms that do not seem to respond to classical activators, but do respond to the Compound C inhibitor.

doi:10.1016/j.cryobiol.2014.10.008