Document Detail


Monoamine oxidase, an intracellular probe of oxygen pressure in isolated cardiac myocytes.
MedLine Citation:
PMID:  6736015     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The activity of monamine oxidase, an enzyme located almost exclusively at the outer mitochondrial membrane, toward the substrate phenylethylamine is used to report the oxygen pressure at the outer mitochondrial membrane of intact cardiac myocytes isolated from hearts of adult rats. The rate of substrate oxidation, under the conditions used, follows the Michaelis-Menten relation, and accordingly can be used as a measure of the local chemical activity of dissolved oxygen. The oxygen pressure at the outer mitochondrial membrane of myocytes, at rest and after 2- to 3-fold stimulation of respiratory oxygen consumption, differs from the extracellular oxygen pressure by at most 2 torr. This implies that most of the large, about 20 torr, difference in oxygen pressure between capillary lumen and mitochondria of the working heart must be extracellular. At physiologically relevant concentrations of the substrates phenylethylamine and norepinephrine, monoamine oxidase activity is relatively insensitive to extracellular oxygen pressure in the range 155 to 8 torr, suggesting a limited role for regulation of biogenic amine oxidation by oxygen availability.
Authors:
I R Katz; J B Wittenberg; B A Wittenberg
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The Journal of biological chemistry     Volume:  259     ISSN:  0021-9258     ISO Abbreviation:  J. Biol. Chem.     Publication Date:  1984 Jun 
Date Detail:
Created Date:  1984-07-30     Completed Date:  1984-07-30     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  2985121R     Medline TA:  J Biol Chem     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  7504-9     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Animals
Kinetics
Mathematics
Monoamine Oxidase / metabolism*
Monoamine Oxidase Inhibitors / pharmacology
Myocardium / cytology*
Oxidation-Reduction
Oxygen*
Oxygen Consumption / drug effects
Phenethylamines / metabolism
Pressure
Rats
Grant Support
ID/Acronym/Agency:
1-K6-733//PHS HHS; AG00085/AG/NIA NIH HHS; HL 19299/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
0/Monoamine Oxidase Inhibitors; 0/Phenethylamines; 64-04-0/phenethylamine; 7782-44-7/Oxygen; EC 1.4.3.4/Monoamine Oxidase

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


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