title: 'Idealized' state 4 and state 3 in mitochondria vs. rest and work in skeletal muscle.
abstract: A computer model of oxidative phosphorylation (OXPHOS) in skeletal muscle is used to compare state 3, intermediate state and state 4 in mitochondria with rest and work in skeletal muscle. 'Idealized' state 4 and 3 in relation to various 'experimental' states 4 and 3 are defined. Theoretical simulations show, in accordance with experimental data, that oxygen consumption (V'O2), ADP and Pi are higher, while ATP/ADP and Δp are lower in rest than in state 4, because of the presence of basal ATP consuming reactions in the former. It is postulated that moderate and intensive work in skeletal muscle is very different from state 3 in isolated mitochondria. V'O2, ATP/ADP, Δp and the control of ATP usage over V'O2 are much higher, while ADP and Pi are much lower in the former. The slope of the phenomenological V'O2-ADP relationship is much steeper during the rest-work transition than during the state 4-state 3 transition. The work state in intact muscle is much more similar to intermediate state than to state 3 in isolated mitochondria in terms of ADP, ATP/ADP, Δp and metabolic control pattern, but not in terms of V'O2. The huge differences between intact muscle and isolated mitochondria are proposed to be caused by the presence of the each-step activation (ESA) mechanism of the regulation of OXPHOS in intact skeletal muscle. Generally, the present study suggests that isolated mitochondria (at least in the absence of Ca2+) cannot serve as a good model of OXPHOS regulation in intact skeletal muscle.
authors: Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland.
authors: Bernard
authors: B
authors: Korzeniewski
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D003198:Computer Simulation; D006801:Humans; D008928:Mitochondria / Q000378:metabolism*; D008954:Models, Biological; D018482:Muscle, Skeletal / Q000502:physiology*; D010085:Oxidative Phosphorylation; D010101:Oxygen Consumption; D012146:Rest
chemical_list: D000255:Adenosine Triphosphate
references: Biochem J. 1998 Mar 15;330 ( Pt 3):1189-95
references: 9494084
references: Proc Natl Acad Sci U S A. 1989 Mar;86(5):1583-7
references: 2922400
references: J Biol Chem. 2009 Mar 13;284(11):7091-9
references: 19129175
references: J Physiol Sci. 2010 Sep;60(5):331-41
references: 20596842
references: J Exp Biol. 1985 Mar;115:355-64
references: 4031775
references: Am J Physiol. 1985 May;248(5 Pt 1):C542-9
references: 3993772
references: J Physiol. 2004 Feb 1;554(Pt 3):755-63
references: 14634202
references: Am J Physiol Cell Physiol. 2000 Apr;278(4):C747-64
references: 10751324
references: J Biol Chem. 2000 Mar 3;275(9):6129-34
references: 10692403
references: Eur J Biochem. 1990 Mar 10;188(2):321-5
references: 2156699
references: Proc Natl Acad Sci U S A. 1985 Dec;82(24):8384-8
references: 3866229
references: Acta Physiol Scand. 1997 Nov;161(3):345-53
references: 9401587
references: Biochem J. 2000 Apr 1;347 Pt 1:45-53
references: 10727400
references: J Appl Physiol (1985). 2014 Jan 1;116(1):83-94
references: 24157529
references: Pflugers Arch. 1973 Nov 28;344(3):217-32
references: 4797912
references: Eur J Biochem. 1998 Mar 15;252(3):508-12
references: 9546667
references: J Physiol. 2000 Oct 15;528 Pt 2:379-88
references: 11034627
references: Biochemistry. 2013 Apr 23;52(16):2793-809
references: 23547908
references: Adv Enzymol Relat Subj Biochem. 1956;17:65-134
references: 13313307
references: Biophys Chem. 2007 Sep;129(2-3):93-110
references: 17566629
references: Biochem J. 2011 Apr 15;435(2):297-312
references: 21726199
references: Am J Physiol Cell Physiol. 2009 Jan;296(1):C25-46
references: 18829894
references: J Physiol. 1985 Sep;366:233-49
references: 4057091
references: Annu Rev Physiol. 1990;52:451-66
references: 2184763
references: Am J Physiol. 1995 Apr;268(4 Pt 2):H1453-61
references: 7733346
references: Biochim Biophys Acta. 1996 Aug 7;1276(1):45-50
references: 8764890
references: J Physiol. 2008 Sep 1;586(Pt 17):4193-208
references: 18617566
references: J Biol Chem. 1955 Nov;217(1):383-93
references: 13271402
references: Biophys Chem. 2004 Jul 1;110(1-2):147-69
references: 15223151
references: Physiol Rev. 2007 Jan;87(1):29-67
references: 17237342
references: Am J Physiol Cell Physiol. 2000 Feb;278(2):C423-35
references: 10666039
references: Eur J Biochem. 1984 Jul 16;142(2):417-24
references: 6086353
references: Am J Physiol. 1988 Apr;254(4 Pt 1):C548-53
references: 3354652
references: Biochem J. 1992 Sep 1;286 ( Pt 2):313-30
references: 1530563
references: Proc Natl Acad Sci U S A. 1982 Dec;79(24):7714-8
references: 6218501
references: Eur J Biochem. 1990 Mar 10;188(2):313-9
references: 2156698
references: Cell Mol Bioeng. 2012 Mar;5(1):92-112
references: 22942911
references: J Biol Chem. 1982 Mar 25;257(6):2754-7
references: 7061448
references: Biochem J. 1995 Oct 1;311 ( Pt 1):35-9
references: 7575476
references: Biochem J. 1996 Nov 15;320 ( Pt 1):329-34
references: 8947505
references: Biochim Biophys Acta. 2000 Feb 24;1457(1-2):57-70
references: 10692550
references: Am J Physiol Cell Physiol. 2007 Jan;292(1):C115-24
references: 16837647
references: Am J Physiol. 1999 Mar;276(3 Pt 1):C692-9
references: 10069997
references: Biochem J. 2012 May 1;443(3):747-55
references: 22295911
references: Biophys Chem. 2001 Aug 30;92(1-2):17-34
references: 11527576
references: Biochim Biophys Acta. 1993 Feb 8;1141(1):58-64
references: 8382080
references: Biochem J. 1996 Oct 1;319 ( Pt 1):143-8
references: 8870661
references: Biochem J. 1995 Nov 15;312 ( Pt 1):163-7
references: 7492307