ISSN:
1573-4935
Keywords:
Reactive oxygen species (ROS)
;
mitochondria
;
Ca2+ transport
;
energy transduction
;
electron paramagnetic resonance (EPR)
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract The relationship between Ca2+ transport and energy transduction of myocardial mitochondria in the presence of reactive oxygen species was investigated. Following treatment with oxygen free radicals [superoxide(O 2 • ) or hydroxyl radical (•)OH], lipid free radicals in myocardial mitochondrial membrane could be detected by using the method of EPR spin trap. Simultaneously there were obvious alterations in the free Ca2+ ([Ca2+]m) in the mitochondrial matrix; the physical state of membrane lipid; the efficiency of oxidative phosphorylation (ADP/O); the value of the respiratory control ratio (RCR); and the membrane potential of the inner membrane of myocardial mitochondria. If the concentrations of reactive oxygen species were reduced by about 30%, the alterations in the physical state of the membrane lipid and energy transduction of myocardial mitochondria were not observed, but the changes in Ca2+ homeostasis remained. We conclude that Ca2+ transport by myocardial mitochondria is more sensitive to agents such as (O 2 • ) or •OH, etc. than are oxidation phosphorylation and the respiratory chain.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1027316424985
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