Malate–aspartate shuttle and exogenous NADH/cytochrome c electron transport pathway as two independent cytosolic reducing equivalent transfer systems

2012 ◽  
Vol 518 (2) ◽  
pp. 157-163 ◽  
Author(s):  
Daniela Isabel Abbrescia ◽  
Gianluigi La Piana ◽  
Nicola Elio Lofrumento
Keyword(s):  
Electron Transport ◽  
Cytochrome C ◽  
Transport Pathway ◽  
Reducing Equivalent ◽  
Nadh Cytochrome ◽  
Electron Transport Pathway ◽  
Malate Aspartate Shuttle

Ceramide-induced activation of cytosolic NADH/cytochrome c electron transport pathway: An additional source of energy for apoptosis

2010 ◽  
Vol 504 (2) ◽  
pp. 210-220 ◽  
Author(s):  
Vincenza Gorgoglione ◽  
Valeria Palmitessa ◽  
Dario Domenico Lofrumento ◽  
Gianluigi La Piana ◽  
Daniela Isabel Abbrescia ◽  
...  
Keyword(s):  
Electron Transport ◽  
Cytochrome C ◽  
Additional Source ◽  
Transport Pathway ◽  
Nadh Cytochrome ◽  
Electron Transport Pathway

Stimulation by pro-apoptotic valinomycin of cytosolic NADH/cytochrome c electron transport pathway—Effect of SH reagents

2016 ◽  
Vol 76 ◽  
pp. 12-18 ◽  
Author(s):  
Dario Domenico Lofrumento ◽  
Gianluigi La Piana ◽  
Valeria Palmitessa ◽  
Daniela Isabel Abbrescia ◽  
Nicola Elio Lofrumento
Keyword(s):  
Electron Transport ◽  
Cytochrome C ◽  
Transport Pathway ◽  
Sh Reagents ◽  
Nadh Cytochrome ◽  
Electron Transport Pathway ◽  
Pathway Effect

scholarly journals Effects of L-Malate on Mitochondrial Oxidoreductases in Liver of Aged Rats

2011 ◽  
pp. 329-336 ◽  
Author(s):  
J.-L. WU ◽  
Q.-P. WU ◽  
Y.-P. PENG ◽  
J.-M. ZHANG
Keyword(s):  
Electron Transport ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Electron Transport Chain ◽  
Nadh Dehydrogenase ◽  
Tricarboxylic Acid Cycle ◽  
Radical Scavenger ◽  
Aged Rats ◽  
Transport Chain ◽  
Nadh Cytochrome

Accumulation of oxidative damage has been implicated to be a major causative factor in the decline in physiological functions that occur during the aging process. The mitochondrial respiratory chain is a powerful source of reactive oxygen species (ROS), considered as the pathogenic agent of many diseases and aging. L-malate, a tricarboxylic acid cycle intermediate, plays an important role in transporting NADH from cytosol to mitochondria for energy production. Previous studies in our laboratory reported L-malate as a free radical scavenger in aged rats. In the present study we focused on the effect of L-malate on the activities of electron transport chain in young and aged rats. We found that mitochondrial membrane potential (MMP) and the activities of succinate dehydrogenase, NADH-cytochrome c oxidoreductase and cytochrome c oxidase in liver of aged rats were significantly decreased when compared to young control rats. Supplementation of L-malate to aged rats for 30 days slightly increased MMP and improved the activities of NADH-dehydrogenase, NADH-cytochrome c oxidoreductase and cytochrome c oxidase in liver of aged rats when compared with aged control rats. In young rats, L-malate administration increased only the activity of NADH-dehydrogenase. Our result suggested that L-malate could improve the activities of electron transport chain enzymes in aged rats

Acute inhibition of respiratory capacity of muscle reduces peak oxygen consumption

1990 ◽  
Vol 259 (6) ◽  
pp. C889-C896 ◽  
Author(s):  
R. M. McAllister ◽  
R. L. Terjung
Keyword(s):  
Oxygen Consumption ◽  
Electron Transport ◽  
Cytochrome C ◽  
Peak Oxygen Consumption ◽  
Dependent Manner ◽  
Cytochrome C Reductase ◽  
Energy Demands ◽  
Hindlimb Muscle ◽  
Nadh Cytochrome

Electron transport capacity of skeletal muscle was inhibited in situ in an acute dose-dependent manner with myxothiazol, a tight-binding inhibitor of ubiquinone-cytochrome c reductase, complex III of the respiratory chain. Peak oxygen consumption of rat hindlimb muscle was determined via consecutive 10-min isometric contraction (100 ms at 100 Hz) periods of increasing energy demands (4, 8, 15, 30, 45, and 60 tetani/min), using an isolated hindlimb preparation perfused with a high oxygen delivery (approximately 6-8 mumol.min-1.g-1). Peak oxygen consumption decreased from 4.61 +/- 0.19 mumol.min-1.g-1 (control) in a dose-dependent manner to 0.73 +/- 0.07 mumol.min-1.g-1 at 0.50 microM myxothiazol in blood. Oxygen extraction decreased from 65 to 12% of delivered oxygen. Furthermore, the reduction in peak respiratory rate became evident at lower energy demands of the contraction sequence. Myxothiazol inhibition of respiration was not dependent on the presence of muscle contractions but was evident when mitochondria were uncoupled with carbonyl cyanide m-chlorophenylhydrazone. A 50% effective dosage (ED50) of 0.21 microM myxothiazol for inhibition of peak oxygen consumption closely resembled the inhibition of NADH-cytochrome c reductase activity (ED50 of 0.27 microM) determined from homogenates of the same muscles. This suggests that the peak oxygen consumption of skeletal muscle is tightly coupled to the capacity for electron transport evaluated by flux through NADH-cytochrome c reductase. If the enzyme activity measured in vitro correctly represents available enzymatic capacity within contracting muscle, approximately 75% of electron transport capacity for handling reducing equivalents generated from NADH is utilized during peak oxygen consumption of rat hindlimb muscle contracting in situ.

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