Linked Life Data

7808448

Source:http://linkedlifedata.com/resource/pubmed/id/7808448

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1995-1-31
pubmed:abstractText
The influence of mitochondrial creatine kinase on subcellular high energy systems has been investigated using isolated rat heart mitochondria, mitoplasts and intact heart and skeletal muscle tissue. In isolated mitochondria, the creatine kinase is functionally coupled to oxidative phosphorylation at active respiratory chain, so that it catalyses the formation of creatine phosphate against its thermodynamic equilibrium. Therefore the mass action ratio is shifted from the equilibrium ratio to lower values. At inhibited respiration, it is close to the equilibrium value, irrespective of the mechanism of the inhibition. The same results were obtained for mitoplasts under conditions where the mitochondrial creatine kinase is still associated with the inner membrane. In intact tissue increasing amounts of creatine phosphate are found in the mitochondrial compartment when respiration and/or muscle work are increased. It is suggested that at high rates of oxidative phosphorylation creatine phosphate is accumulated in the intermembrane space due to the high activity of mitochondrial creatine kinase and the restricted permeability of reactants into the extramitochondrial space. A certain amount of this creatine phosphate 'leaks' into the mitochondrial matrix. This leak is confirmed in isolated rat heart mitochondria where creatine phosphate is taken up when it is generated by the mitochondrial creatine kinase reaction. At inhibited creatine kinase, external creatine phosphate is not taken up. Likewise, mitoplasts only take up creatine phosphate when creatine kinase is still associated with the inner membrane. Both findings indicate that uptake is dependent on the functional active creatine kinase coupled to oxidative phosphorylation. Creatine phosphate uptake into mitochondria is inhibited with carboxyatractyloside.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0300-8177
pubmed:author
pubmed:issnType
Print
pubmed:volume
133-134
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
105-13
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:articleTitle
Influence of mitochondrial creatine kinase on the mitochondrial/extramitochondrial distribution of high energy phosphates in muscle tissue: evidence for a leak in the creatine shuttle.
pubmed:affiliation
Institut für Physiologische Chemie I, Universität Düsseldorf, Germany.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't