Laner 2016 Abstract Mito Xmas Meeting Innsbruck
|OXPHOS and ET capacity in permeabilized fibres of canine superathletes.|
Comparative mitochondrial physiology strongly relies on quantitative data sets for comparison of OXPHOS capacities and respiratory control patterns between species and tissues. Combination and interpretation of a wide variety of studies requires standardization of respiratory protocols, implementation of quality control criteria, and consistency of normalization. Previously we described a reference method for the application of a cytochrome c threshold as exclusion criterion in mitochondrial OXPHOS analyses . Alaskan sled dogs (N=6) were studied 72 to 120 h after finishing a competitive 1,000 mile race within less than nine days. Permeabilized fibres (0.81-1.28 mg ± 0.12 SD wet weight per assay) were prepared from needle biopsies and immediately studied by high-resolution respirometry  using 12 chambers in parallel (Oroboros Oxygraph-2k). Compared to human skeletal muscle fibres, the canine samples were more delicate to handle, highly sticky and appeared to be fragile, disintegrating to various degrees during substrate-uncoupler-inhibitor titration (SUIT) protocols in mt-respiration medium MiR06Cr. Two substrate-uncoupler-inhibitor titration protocols were applied (Fig. 1). SUIT1 emphasized pathway control with fatty acid oxidation (F) versus carbohydrate oxidation capacity, whereas the focus of SUIT2 was on coupling control with N-linked substrates. Both protocols were designed to provide a common reference state of NS-linked ET capacity, in comparison to separate N- and S-linked pathway control states (N versus S). NS-linked ET capacity was 262±41 pmol∙s-1∙mg-1 Ww independent of the presence or absence of 0.2 mM octanoyl carnitine (F). This is the highest value so far reported for mammalian skeletal muscle. Top human endurance athletes have a NS-linked ET capacity approaching 200 pmol∙s-1∙mg-1 Ww , compared to 153±19 pmol∙s-1∙mg-1 Ww in competitive racing horses .
Labels: MiParea: Respiration, Comparative MiP;environmental MiP, Exercise physiology;nutrition;life style
Organism: Dog Tissue;cell: Skeletal muscle Preparation: Permeabilized tissue
Coupling state: LEAK, OXPHOS, ET Pathway: F, N, S, NS, ROX HRR: Oxygraph-2k Event: Poster
- Laner V(1), Boushel RC(2), Hamilton KL(3), Miller BF(3), Williamson KK(4), Davis MS(5), Gnaiger E(1,6)
- Oroboros Instruments Corp, Innsbruck, Austria
- School Kinesiology, Univ British Columbia, Vancouver, BC, Canada
- Dept Health Exercise Sc, Colorado State Univ, Fort Collins, CO, USA
- Waypoint Veterinary Education, Edmond, OK, USA
- Dept Physiological Sc, Oklahoma State Univ, Stillwater, OK, USA
- Dept Visceral, Transplant Thoracic Surgery, D. Swarovski Research Lab, Medical Univ Innsbruck, Austria
- Laner V, Boushel RC, Hamilton KL, Miller BF, Williamson KK, Davis MS, Gnaiger E (2014) Cytochrome c flux control factor as a quality criterion in respiratory OXPHOS analysis in canine permeabilized fibres. Mitochondr Physiol Network 19.13:63-4.
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- Gnaiger E (2009) Capacity of oxidative phosphorylation in human skeletal muscle. New perspectives of mitochondrial physiology. Int J Biochem Cell Biol 41:1837-45.
- Votion DM, Gnaiger E, Lemieux H, Mouithys-Mickalad A, Serteyn D (2012) Physical fitness and mitochondrial respiratory capacity in horse skeletal muscle. PLoS One 7:e34890.