caa a22 4500 605514275 CHVBK 20210128100704.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s00360-015-0893-9 doi (NATIONALLICENCE)springer-10.1007/s00360-015-0893-9 Maintenance of skeletal muscle energy homeostasis during prolonged wintertime fasting in the raccoon dog ( Nyctereutes procyonoides ) [Elektronische Daten] [Sanni Kinnunen, Satu Mänttäri, Karl-Heinz Herzig, Petteri Nieminen, Anne-Mari Mustonen, Seppo Saarela] The raccoon dog (Nyctereutes procyonoides) is a canid species with autumnal fattening and prolonged wintertime fasting. Nonpathological body weight cycling and the ability to tolerate food deficiency make this species a unique subject for studying physiological mechanisms in energy metabolism. AMP-activated protein kinase (AMPK) is a cellular energy sensor regulating energy homeostasis. During acute fasting, AMPK promotes fatty acid oxidation and enhances glucose uptake. We evaluated the effects of prolonged fasting on muscle energy metabolism in farm-bred raccoon dogs. Total and phosphorylated AMPK and acetyl-CoA carboxylase (ACC), glucose transporter 4 (GLUT 4), insulin receptor and protein kinase B (Akt) protein expressions of hind limb muscles were determined by Western blot after 10weeks of fasting. Plasma insulin, leptin, ghrelin, glucose and free fatty acid levels were measured, and muscle myosin heavy chain (MHC) isoform composition analyzed. Fasting had no effects on AMPK phosphorylation, but total AMPK expression decreased in m. rectus femoris, m. tibialis anterior and m. extensor digitorum longus resulting in a higher phosphorylation ratio. Decreased total expression was also observed for ACC. Fasting did not influence GLUT 4, insulin receptor or Akt expression, but Akt phosphorylation was lower in m. flexor digitorum superficialis and m. extensor digitorum longus. Three MHC isoforms (I, IIa and IIx) were detected without differences in composition between the fasted and control animals. The studied muscles were resistant to prolonged fasting indicating that raccoon dogs have an effective molecular regulatory system for preserving skeletal muscle function during wintertime immobility and fasting. Springer-Verlag Berlin Heidelberg, 2015 ACC nationallicence Akt nationallicence AMPK nationallicence Energy metabolism nationallicence Food deprivation nationallicence GLUT 4 nationallicence Skeletal muscle nationallicence ACC : Acetyl-CoA carboxylase nationallicence Akt : Protein kinase B nationallicence AMPK : AMP-activated protein kinase nationallicence EDL : m. extensor digitorum longus nationallicence FDS : m. flexor digitorum superficialis nationallicence FFA : Free fatty acid nationallicence GA : m. gastrocnemius nationallicence GAPDH : Glyceraldehyde 3-phosphate dehydrogenase nationallicence GLUT 4 : Glucose transporter 4 nationallicence IR : Insulin receptor nationallicence MHC : Myosin heavy chain nationallicence pAMPK : Phosphorylated AMPK (active form) nationallicence RF : m. rectus femoris nationallicence SDH : Succinate dehydrogenase nationallicence SDS-PAGE : Sodium dodecyl sulfate-polyacrylamide gel electrophoresis nationallicence TA : m. tibialis anterior nationallicence Kinnunen Sanni Department of Biology, University of Oulu, P.O. Box 3000, 90014, Oulu, Finland aut Mänttäri Satu Finnish Institute of Occupational Health, Aapistie 1, 90220, Oulu, Finland aut Herzig Karl-Heinz Institute of Biomedicine, Biocenter of Oulu, University of Oulu, P.O. Box 5000, 90014, Oulu, Finland aut Nieminen Petteri Institute of Biomedicine/Anatomy, School of Medicine, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland aut Mustonen Anne-Mari Institute of Biomedicine/Anatomy, School of Medicine, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland aut Saarela Seppo Department of Biology, University of Oulu, P.O. Box 3000, 90014, Oulu, Finland aut Journal of Comparative Physiology B Springer Berlin Heidelberg 185/4(2015-05-01), 435-445 0174-1578 185:4<435 2015 185 360 https://doi.org/10.1007/s00360-015-0893-9 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00360-015-0893-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kinnunen Sanni Department of Biology, University of Oulu, P.O. Box 3000, 90014, Oulu, Finland aut NATIONALLICENCE 700 1- Mänttäri Satu Finnish Institute of Occupational Health, Aapistie 1, 90220, Oulu, Finland aut NATIONALLICENCE 700 1- Herzig Karl-Heinz Institute of Biomedicine, Biocenter of Oulu, University of Oulu, P.O. Box 5000, 90014, Oulu, Finland aut NATIONALLICENCE 700 1- Nieminen Petteri Institute of Biomedicine/Anatomy, School of Medicine, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland aut NATIONALLICENCE 700 1- Mustonen Anne-Mari Institute of Biomedicine/Anatomy, School of Medicine, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland aut NATIONALLICENCE 700 1- Saarela Seppo Department of Biology, University of Oulu, P.O. Box 3000, 90014, Oulu, Finland aut NATIONALLICENCE 773 0- Journal of Comparative Physiology B Springer Berlin Heidelberg 185/4(2015-05-01), 435-445 0174-1578 185:4<435 2015 185 360