Document Detail


Primary causes of decreased mitochondrial oxygen consumption during metabolic depression in snail cells.
MedLine Citation:
PMID:  11792646     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Cells isolated from the hepatopancreas of estivating snails (Helix aspersa) have strongly depressed mitochondrial respiration compared with controls. Mitochondrial respiration was divided into substrate oxidation (which produces the mitochondrial membrane potential) and ATP turnover and proton leak (which consume it). The activity of substrate oxidation (and probably ATP turnover) decreased, whereas the activity of proton leak remained constant in estivation. These primary changes resulted in a lower mitochondrial membrane potential in hepatopancreas cells from estivating compared with active snails, leading to secondary decreases in respiration to drive ATP turnover and proton leak. The respiration to drive ATP turnover and proton leak decreased in proportion to the overall decrease in mitochondrial respiration, so that the amount of ATP turned over per O2 consumed remained relatively constant and aerobic efficiency was maintained in this hypometabolic state. At least 75% of the total response of mitochondrial respiration to estivation was caused by primary changes in the kinetics of substrate oxidation, with only 25% or less of the response occurring through primary effects on ATP turnover.
Authors:
Tammie Bishop; Julie St-Pierre; Martin D Brand
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  American journal of physiology. Regulatory, integrative and comparative physiology     Volume:  282     ISSN:  0363-6119     ISO Abbreviation:  Am. J. Physiol. Regul. Integr. Comp. Physiol.     Publication Date:  2002 Feb 
Date Detail:
Created Date:  2002-01-16     Completed Date:  2002-02-14     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  100901230     Medline TA:  Am J Physiol Regul Integr Comp Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  R372-82     Citation Subset:  IM    
Affiliation:
Medical Research Council, Dunn Human Nutrition Unit, Cambridge CB2 2XY, United Kingdom. tammie@well.ox.ac.uk
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MeSH Terms
Descriptor/Qualifier:
Adenosine Triphosphate / metabolism
Animals
Cell Respiration / physiology
Energy Metabolism / physiology
Estivation / physiology*
Helix (Snails) / metabolism*
Indicators and Reagents / pharmacokinetics
Liver / cytology,  metabolism
Membrane Potentials / physiology
Mitochondria / metabolism*
Onium Compounds / pharmacokinetics
Oxidation-Reduction
Oxygen Consumption / physiology*
Pancreas / cytology,  metabolism
Protons
Trityl Compounds / pharmacokinetics
Chemical
Reg. No./Substance:
0/Indicators and Reagents; 0/Onium Compounds; 0/Protons; 0/Trityl Compounds; 15912-74-0/triphenylmethylphosphonium; 56-65-5/Adenosine Triphosphate

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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