Functional complexes of mitochondria with Ca,MgATPases of myofibrils and sarcoplasmic reticulum in muscle cells. 2001

E K Seppet, and T Kaambre, and P Sikk, and T Tiivel, and H Vija, and M Tonkonogi, and K Sahlin, and L Kay, and F Appaix, and U Braun, and M Eimre, and V A Saks
Department of Pathophysiology, University of Tartu, Estonia.

Regulation of mitochondrial respiration in situ in the muscle cells was studied by using fully permeabilized muscle fibers and cardiomyocytes. The results show that the kinetics of regulation of mitochondrial respiration in situ by exogenous ADP are very different from the kinetics of its regulation by endogenous ADP. In cardiac and m. soleus fibers apparent K(m) for exogenous ADP in regulation of respiration was equal to 300-400 microM. However, when ADP production was initiated by intracellular ATPase reactions, the ADP concentration in the medium leveled off at about 40 microM when about 70% of maximal rate of respiration was achieved. Respiration rate maintained by intracellular ATPases was suppressed about 20-30% during exogenous trapping of ADP with excess pyruvate kinase (PK, 20 IU/ml) and phosphoenolpyruvate (PEP, 5 mM). ADP flux via the external PK+PEP system was decreased by half by activation of mitochondrial oxidative phosphorylation. Creatine (20 mM) further activated the respiration in the presence of PK+PEP. It is concluded that in oxidative muscle cells mitochondria behave as if they were incorporated into functional complexes with adjacent ADP producing systems - with the MgATPases in myofibrils and Ca,MgATPases of sarcoplasmic reticulum.

UI MeSH Term Description Entries
D007700 Kinetics The rate dynamics in chemical or physical systems.
D008297 Male Males
D008810 Mice, Inbred C57BL One of the first INBRED MOUSE STRAINS to be sequenced. This strain is commonly used as genetic background for transgenic mouse models. Refractory to many tumors, this strain is also preferred model for studying role of genetic variations in development of diseases. Mice, C57BL,Mouse, C57BL,Mouse, Inbred C57BL,C57BL Mice,C57BL Mice, Inbred,C57BL Mouse,C57BL Mouse, Inbred,Inbred C57BL Mice,Inbred C57BL Mouse
D008929 Mitochondria, Heart The mitochondria of the myocardium. Heart Mitochondria,Myocardial Mitochondria,Mitochondrion, Heart,Heart Mitochondrion,Mitochondria, Myocardial
D008931 Mitochondria, Muscle Mitochondria of skeletal and smooth muscle. It does not include myocardial mitochondria for which MITOCHONDRIA, HEART is available. Sarcosomes,Mitochondrion, Muscle,Muscle Mitochondria,Muscle Mitochondrion,Sarcosome
D008956 Models, Chemical Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment. Chemical Models,Chemical Model,Model, Chemical
D009206 Myocardium The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow. Muscle, Cardiac,Muscle, Heart,Cardiac Muscle,Myocardia,Cardiac Muscles,Heart Muscle,Heart Muscles,Muscles, Cardiac,Muscles, Heart
D010085 Oxidative Phosphorylation Electron transfer through the cytochrome system liberating free energy which is transformed into high-energy phosphate bonds. Phosphorylation, Oxidative,Oxidative Phosphorylations,Phosphorylations, Oxidative
D010101 Oxygen Consumption The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346) Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D002478 Cells, Cultured Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others. Cultured Cells,Cell, Cultured,Cultured Cell

Related Publications

E K Seppet, and T Kaambre, and P Sikk, and T Tiivel, and H Vija, and M Tonkonogi, and K Sahlin, and L Kay, and F Appaix, and U Braun, and M Eimre, and V A Saks
June 2003, The Journal of experimental biology,
E K Seppet, and T Kaambre, and P Sikk, and T Tiivel, and H Vija, and M Tonkonogi, and K Sahlin, and L Kay, and F Appaix, and U Braun, and M Eimre, and V A Saks
August 1979, Biochemical Society transactions,
E K Seppet, and T Kaambre, and P Sikk, and T Tiivel, and H Vija, and M Tonkonogi, and K Sahlin, and L Kay, and F Appaix, and U Braun, and M Eimre, and V A Saks
August 1999, Journal of applied physiology (Bethesda, Md. : 1985),
E K Seppet, and T Kaambre, and P Sikk, and T Tiivel, and H Vija, and M Tonkonogi, and K Sahlin, and L Kay, and F Appaix, and U Braun, and M Eimre, and V A Saks
August 1986, Cell calcium,
E K Seppet, and T Kaambre, and P Sikk, and T Tiivel, and H Vija, and M Tonkonogi, and K Sahlin, and L Kay, and F Appaix, and U Braun, and M Eimre, and V A Saks
April 2020, Antioxidants & redox signaling,
E K Seppet, and T Kaambre, and P Sikk, and T Tiivel, and H Vija, and M Tonkonogi, and K Sahlin, and L Kay, and F Appaix, and U Braun, and M Eimre, and V A Saks
September 2009, Cell calcium,
E K Seppet, and T Kaambre, and P Sikk, and T Tiivel, and H Vija, and M Tonkonogi, and K Sahlin, and L Kay, and F Appaix, and U Braun, and M Eimre, and V A Saks
February 1985, The Biochemical journal,
E K Seppet, and T Kaambre, and P Sikk, and T Tiivel, and H Vija, and M Tonkonogi, and K Sahlin, and L Kay, and F Appaix, and U Braun, and M Eimre, and V A Saks
September 1979, Cell and tissue research,
E K Seppet, and T Kaambre, and P Sikk, and T Tiivel, and H Vija, and M Tonkonogi, and K Sahlin, and L Kay, and F Appaix, and U Braun, and M Eimre, and V A Saks
April 1982, Canadian journal of physiology and pharmacology,
E K Seppet, and T Kaambre, and P Sikk, and T Tiivel, and H Vija, and M Tonkonogi, and K Sahlin, and L Kay, and F Appaix, and U Braun, and M Eimre, and V A Saks
January 2005, Cell calcium,
Copied contents to your clipboard!