Linked Life Data

10939635

Source:http://linkedlifedata.com/resource/pubmed/id/10939635

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2000-11-15
pubmed:abstractText
In saponin-skinned muscle fibers from adult rat heart and m. soleus the apparent affinity of the mitochondrial oxidative phosphorylation system for ADP (Km = 200-400 microM) is much lower than in isolated mitochondria (Km = 10-20 microM). This suggests a limited permeability of the outer mitochondrial membrane (OMM) to adenine nucleotides in slow-twitch muscle cells. We have studied the postnatal changes in the affinity of mitochondrial respiration for ADP, in relation to morphological alterations and expression of mitochondrial creatine kinase (mi-CK) in rat heart in vivo. Analysis of respiration of skinned fibers revealed a gradual decrease in the apparent affinity of mitochondria to ADP throughout 6 weeks post partum that indicates the development of mechanism which increasingly limits the access of ADP to mitochondria. The expression of mi-CK started between the 1st and 2nd weeks and reached the adult levels after 6 weeks. This process was associated with increases in creatine-activated respiration and affinity of oxidative phosphorylation to ADP thus reflecting the progressive coupling of mi-CK to adenine nucleotide translocase. Laser confocal microscopy revealed significant changes in rearrangement of mitochondria in cardiac cells: while the mitochondria of variable shape and size appeared to be random-clustered in the cardiomyocytes of 1 day old rat, they formed a fine network between the myofibrils by the age of 3 weeks. These results allow to conclude that in early period of development, i.e. within 2-3 weeks, the diffusion of ADP to mitochondria becomes progressively restricted, that appears to be related to significant structural rearrangements such as formation of the mitochondrial network. Later (after 3 weeks) the control shifts to mi-CK, which by coupling to adenine nucleotide translocase, allows to maximally activate the processes of oxidative phosphorylation despite limited access of ADP through the OMM.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0300-8177
pubmed:author
pubmed:issnType
Print
pubmed:volume
208
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
119-28
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:10939635-Adenosine Diphosphate, pubmed-meshheading:10939635-Animals, pubmed-meshheading:10939635-Body Weight, pubmed-meshheading:10939635-Cell Respiration, pubmed-meshheading:10939635-Creatine, pubmed-meshheading:10939635-Creatine Kinase, pubmed-meshheading:10939635-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:10939635-Fluorescent Dyes, pubmed-meshheading:10939635-Heart, pubmed-meshheading:10939635-Kinetics, pubmed-meshheading:10939635-Microscopy, Confocal, pubmed-meshheading:10939635-Mitochondria, Heart, pubmed-meshheading:10939635-Mitochondria, Muscle, pubmed-meshheading:10939635-Mitochondrial ADP, ATP Translocases, pubmed-meshheading:10939635-Muscle, Skeletal, pubmed-meshheading:10939635-Muscle Fibers, Skeletal, pubmed-meshheading:10939635-Myocardium, pubmed-meshheading:10939635-Organ Size, pubmed-meshheading:10939635-Oxidative Phosphorylation, pubmed-meshheading:10939635-Rats, pubmed-meshheading:10939635-Rats, Wistar, pubmed-meshheading:10939635-Trypsin
pubmed:year
2000
pubmed:articleTitle
Developmental changes in regulation of mitochondrial respiration by ADP and creatine in rat heart in vivo.
pubmed:affiliation
Laboratory of Bioenergetics, Institute of Chemical and Biological Physics, Tallinn, Estonia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't