Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2-3
pubmed:dateCreated
2001-3-14
pubmed:abstractText
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.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
1504
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
379-95
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:11245802-Adenosine Diphosphate, pubmed-meshheading:11245802-Adenosine Triphosphate, pubmed-meshheading:11245802-Animals, pubmed-meshheading:11245802-Ca(2+) Mg(2+)-ATPase, pubmed-meshheading:11245802-Cells, Cultured, pubmed-meshheading:11245802-Dinucleoside Phosphates, pubmed-meshheading:11245802-Energy Metabolism, pubmed-meshheading:11245802-Kinetics, pubmed-meshheading:11245802-Male, pubmed-meshheading:11245802-Mice, pubmed-meshheading:11245802-Mice, Inbred C57BL, pubmed-meshheading:11245802-Mitochondria, Heart, pubmed-meshheading:11245802-Mitochondria, Muscle, pubmed-meshheading:11245802-Models, Chemical, pubmed-meshheading:11245802-Muscle Fibers, Skeletal, pubmed-meshheading:11245802-Myocardium, pubmed-meshheading:11245802-Oxidative Phosphorylation, pubmed-meshheading:11245802-Oxygen Consumption, pubmed-meshheading:11245802-Rats, pubmed-meshheading:11245802-Rats, Sprague-Dawley, pubmed-meshheading:11245802-Sarcoplasmic Reticulum
pubmed:year
2001
pubmed:articleTitle
Functional complexes of mitochondria with Ca,MgATPases of myofibrils and sarcoplasmic reticulum in muscle cells.
pubmed:affiliation
Department of Pathophysiology, University of Tartu, Estonia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't