title: Maintenance of skeletal muscle energy homeostasis during prolonged wintertime fasting in the raccoon dog (Nyctereutes procyonoides).
abstract: 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 10 weeks 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.
authors: Department of Biology, University of Oulu, P.O. Box 3000, 90014, Oulu, Finland, sanni.kinnunen@oulu.fi.
authors: Sanni
authors: S
authors: Kinnunen
authors: Satu
authors: S
authors: Mänttäri
authors: Karl-Heinz
authors: KH
authors: Herzig
authors: Petteri
authors: P
authors: Nieminen
authors: Anne-Mari
authors: AM
authors: Mustonen
authors: Seppo
authors: S
authors: Saarela
mesh_terms: D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000378:metabolism; D055372:AMP-Activated Protein Kinases / Q000378:metabolism; D000102:Acetyl-CoA C-Acyltransferase / Q000378:metabolism; D000103:Acetyl-CoA Carboxylase / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D019748:Carbon-Carbon Double Bond Isomerases / Q000378:metabolism; D004734:Energy Metabolism / Q000502:physiology*; D004746:Enoyl-CoA Hydratase / Q000378:metabolism; D005215:Fasting / Q000502:physiology*; D006651:Histocytochemistry; D006706:Homeostasis / Q000502:physiology*; D007328:Insulin / Q000097:blood; D020738:Leptin / Q000097:blood; D018482:Muscle, Skeletal / Q000502:physiology*; D010766:Phosphorylation; D046031:Raccoon Dogs / Q000502:physiology*; D019998:Racemases and Epimerases / Q000378:metabolism; D012621:Seasons
chemical_list: D007328:Insulin; D020738:Leptin; C038784:fatty acid oxidation complex; D015094:3-Hydroxyacyl CoA Dehydrogenases; D000102:Acetyl-CoA C-Acyltransferase; D055372:AMP-Activated Protein Kinases; D004746:Enoyl-CoA Hydratase; D019998:Racemases and Epimerases; D019748:Carbon-Carbon Double Bond Isomerases; D000103:Acetyl-CoA Carboxylase
references: J Appl Physiol (1985). 2001 Sep;91(3):1073-83
references: 11509501
references: Comp Biochem Physiol B Biochem Mol Biol. 2007 May;147(1):20-8
references: 17307375
references: Am J Physiol Endocrinol Metab. 2004 Nov;287(5):E1032-7
references: 15251868
references: Diabetes. 2000 Aug;49(8):1281-7
references: 10923626
references: Eur J Biochem. 1997 Jun 1;246(2):259-73
references: 9208914
references: Diabetes Care. 2001 May;24(5):933-41
references: 11347757
references: Nature. 2000 Oct 19;407(6806):908-13
references: 11057670
references: J Biol Rhythms. 2002 Apr;17(2):155-63
references: 12002162
references: Cell Metab. 2010 Mar 3;11(3):213-9
references: 20197054
references: Zoolog Sci. 2004 Apr;21(4):385-91
references: 15118225
references: J Appl Physiol (1985). 1999 Nov;87(5):1990-5
references: 10562646
references: Am J Physiol Regul Integr Comp Physiol. 2011 Jan;300(1):R150-4
references: 20980624
references: Comp Biochem Physiol B. 1991;100(2):377-80
references: 1724746
references: Physiol Biochem Zool. 2008 Mar-Apr;81(2):138-47
references: 18173360
references: Diabetologia. 2005 Nov;48(11):2354-64
references: 16237515
references: J Clin Invest. 1990 Nov;86(5):1423-7
references: 2243122
references: Chronobiol Int. 2007;24(6):1095-107
references: 18075801
references: J Appl Physiol (1985). 1997 Jan;82(1):219-25
references: 9029219
references: BMC Ecol. 2012 Dec 13;12:27
references: 23237274
references: Am J Physiol Endocrinol Metab. 2002 Jun;282(6):E1239-44
references: 12006353
references: Arch Neurol. 1970 Oct;23(4):369-79
references: 4248905
references: J Appl Physiol (1985). 1996 Jan;80(1):261-70
references: 8847313
references: Nature. 2002 Jan 17;415(6869):339-43
references: 11797013
references: Proc Natl Acad Sci U S A. 1979 Sep;76(9):4350-4
references: 388439
references: J Comp Physiol B. 2004 Jan;174(1):1-12
references: 14520494
references: Mol Cell Biochem. 2010 Nov;344(1-2):151-62
references: 20617369
references: Diabetes. 2003 Jul;52(7):1635-40
references: 12829626
references: J Histochem Cytochem. 1957 Jul;5(4):420-36
references: 13463314
references: J Biomech. 2006;39(8):1480-8
references: 15975583
references: J Histochem Cytochem. 1993 May;41(5):733-43
references: 8468455
references: Biochem J. 2002 Apr 1;363(Pt 1):167-74
references: 11903059
references: J Exp Zool A Comp Exp Biol. 2005 Sep 1;303(9):776-84
references: 16106408
references: Am J Physiol. 1997 Feb;272(2 Pt 1):E262-6
references: 9124333
references: PLoS One. 2012;7(5):e37890
references: 22629468
references: J Clin Endocrinol Metab. 2001 Dec;86(12):5992
references: 11739476
references: FASEB J. 2002 Nov;16(13):1697-712
references: 12409312
references: FEBS Lett. 2003 Jul 3;546(1):113-20
references: 12829246
references: J Muscle Res Cell Motil. 2013 Dec;34(5-6):357-68
references: 24037259
references: J Exp Biol. 2013 Jul 15;216(Pt 14):2587-94
references: 23531815
references: J Cell Biochem. 2009 Oct 1;108(2):458-68
references: 19639604
references: J Endocrinol. 2011 Jun;209(3):317-25
references: 21429964
references: Obesity (Silver Spring). 2007 Nov;15(11):2614-23
references: 18070752
references: Comp Biochem Physiol B Biochem Mol Biol. 2005 Dec;142(4):374-82
references: 16202635
references: Comp Biochem Physiol A Mol Integr Physiol. 2010 Mar;155(3):392-400
references: 20026417
references: FASEB J. 2004 Feb;18(2):350-2
references: 14656997
references: J Biol Chem. 2002 Jul 5;277(27):23977-80
references: 11997383
references: Comp Biochem Physiol A Mol Integr Physiol. 2011 Jul;159(3):322-31
references: 21473923
references: Diabetes. 2002 Feb;51(2):284-92
references: 11812734
references: Cell Metab. 2005 Jan;1(1):15-25
references: 16054041
references: Am J Physiol Endocrinol Metab. 2007 Jun;292(6):E1555-67
references: 17264220
references: Am J Physiol Cell Physiol. 2007 Jan;292(1):C477-87
references: 16943243
references: FASEB J. 2006 Dec;20(14 ):2579-81
references: 17065218
references: Bone. 2011 Apr 1;48(4):878-84
references: 21146643
references: J Physiol. 2006 Aug 15;575(Pt 1):291-303
references: 16763003
references: Am J Physiol. 1997 Dec;273(6 Pt 1):E1107-12
references: 9435525
references: Diabetes. 1997 Aug;46(8):1360-3
references: 9231663