scholarly journals Endurance training increases stimulation of uncoupling of skeletal muscle mitochondria in humans by non-esterified fatty acids: an uncoupling-protein-mediated effect?

2000 ◽  
Vol 351 (3) ◽  
pp. 805 ◽  
Author(s):  
Michail TONKONOGI ◽  
Anna KROOK ◽  
Brandon WALSH ◽  
Kent SAHLIN
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Endurance Training ◽  
Uncoupling Protein ◽  
Muscle Mitochondria ◽  
Skeletal Muscle Mitochondria ◽  
Esterified Fatty Acids ◽  
Stimulation Of

scholarly journals Endurance training increases stimulation of uncoupling of skeletal muscle mitochondria in humans by non-esterified fatty acids: an uncoupling-protein-mediated effect?

2000 ◽  
Vol 351 (3) ◽  
pp. 805-810 ◽  
Author(s):  
Michail TONKONOGI ◽  
Anna KROOK ◽  
Brandon WALSH ◽  
Kent SAHLIN
Keyword(s):  
Fatty Acids ◽  
Endurance Training ◽  
Uncoupling Protein ◽  
Mrna Level ◽  
Relative Increase ◽  
Essential Property ◽  
Mrna Levels ◽  
Purine Nucleotides ◽  
Muscle Mitochondria ◽  
Esterified Fatty Acids

Uncoupled respiration (UCR) is an essential property of muscle mitochondria and has several functions in the cell. We hypothesized that endurance training may alter the magnitude and properties of UCR in human muscle. Isolated mitochondria from muscle biopsies taken before and after 6 weeks of endurance exercise training (n = 8) were analysed for UCR. To investigate the role of uncoupling protein 2 (UCP2) and UCP3 in UCR, the sensitivity of UCR to UCP-regulating ligands (non-esterified fatty acids and purine nucleotides) and UCP2 and UCP3 mRNA expression in muscle were examined. Oleate increased the mitochondrial oxygen consumption rate, an effect that was not attenuated by GDP and/or cyclosporin A. The effect of oleate was significantly greater after compared with before training. Training had no effect on UCP2 or UCP3 mRNA levels, but after training the relative increase in respiration rate induced by oleate was positively correlated with the UCP2 mRNA level. In conclusion, we show that the sensitivity of UCR to non-esterified fatty acids is up-regulated by endurance training. This suggests that endurance training causes intrinsic changes in mitochondrial function, which may enhance the potential for regulation of aerobic energy production, prevent excess free radical generation and contribute to a higher basal metabolic rate.

Artifactual uncoupling by uncoupling protein 3 in yeast mitochondria at the concentrations found in mouse and rat skeletal-muscle mitochondria

2001 ◽  
Vol 361 (1) ◽  
pp. 49-56 ◽  
Author(s):  
James A. HARPER ◽  
Jeff A. STUART ◽  
Mika B. JEKABSONS ◽  
Damien ROUSSEL ◽  
Kevin M. BRINDLE ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Uncoupling Protein ◽  
Mitochondrial Protein ◽  
Yeast Mitochondria ◽  
Rat Skeletal Muscle ◽  
Muscle Mitochondria ◽  
Skeletal Muscle Mitochondria ◽  
Uncoupling Protein 3 ◽  
Brown Adipose

Western blots detected uncoupling protein 3 (UCP3) in skeletal-muscle mitochondria from wild-type but not UCP3 knock-out mice. Calibration with purified recombinant UCP3 showed that mouse and rat skeletal muscle contained 0.14μg of UCP3/mg of mitochondrial protein. This very low UCP3 content is 200–700-fold less than the concentration of UCP1 in brown-adipose-tissue mitochondria from warm-adapted hamster (24–84μg of UCP1/mg of mitochondrial protein). UCP3 was present in brown-adipose-tissue mitochondria from warm-adapted rats but was undetectable in rat heart mitochondria. We expressed human UCP3 in yeast mitochondria at levels similar to, double and 7-fold those found in rodent skeletal-muscle mitochondria. Yeast mitochondria containing UCP3 were more uncoupled than empty-vector controls, particularly at concentrations that were 7-fold physiological. However, uncoupling by UCP3 was not stimulated by the known activators palmitate and superoxide; neither were they inhibited by GDP, suggesting that the observed uncoupling was a property of non-native protein. As a control, UCP1 was expressed in yeast mitochondria at similar concentrations to that of UCP3 and at up to 50% of the physiological level of UCP1. Low levels of UCP1 gave palmitate-dependent and GDP-sensitive proton conductance but higher levels of UCP1 caused an additional GDP-insensitive uncoupling artifact. We conclude that the uncoupling of yeast mitochondria by high levels of UCP3 expression is entirely an artifact and provides no evidence for any native uncoupling activity of the protein.

A magnesium-responsive defect of respiration and oxidative phosphorylation in skeletal muscle mitochondria of dystrophic hamsters

1970 ◽  
Vol 48 (12) ◽  
pp. 1332-1338 ◽  
Author(s):  
K. Wrogemann ◽  
M. C. Blanchaer ◽  
B. E. Jacobson
Keyword(s):  
Skeletal Muscle ◽  
Oxidative Phosphorylation ◽  
Respiratory Rate ◽  
Test System ◽  
Muscle Mitochondria ◽  
Skeletal Muscle Mitochondria ◽  
Muscle Necrosis ◽  
Presence And Absence ◽  
Stimulation Of

Skeletal muscle mitochondria were isolated in the presence and absence of the proteinase Nagarse from dystrophic hamsters of the BIO 14.6 strain, aged 45–196 days, and from normal hamsters. Mitochondria from the dystrophic animals prepared by glass-on-glass homogenization without Nagarse in 0.25 M sucrose – 1 mM EDTA, pH 7.4, did not differ from normal in their respiratory rate or capacity for oxidative phosphorylation. However, these functions were subnormal in mitochondria isolated with Nagarse from the same animals, both in the presence and absence of albumin. Respiration measured with an O2 electrode was reduced by 50–70% and the stimulation of O2 uptake normally seen after ADP addition was minimal or absent. This was most marked in mitochondria from young hamsters about 65 days old with muscle necrosis. The defect was ameliorated by addition to the Polarographie test system of an ATP trap or of Mg2+, one of the trap constituents. This ion, when added to the defective mitochondria prior to ADP and substrate, restored respiration and oxidative phosphorylation to values that did not differ significantly from those found with skeletal muscle mitochondria of normal hamsters.

A Relationship between α-Tocopherol and Polyunsaturated Fatty Acids in Chicken and Porcine Skeletal Muscle Mitochondria

1984 ◽  
Vol 48 (11) ◽  
pp. 2827-2830
Author(s):  
Kiyoshi Yamauchi ◽  
Yasutada Nagai ◽  
Kentaro Yada ◽  
Tomio Ohashi ◽  
Albert M. Pearson
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Muscle Mitochondria ◽  
Skeletal Muscle Mitochondria

scholarly journals Endurance training increases the efficiency of rat skeletal muscle mitochondria

2016 ◽  
Vol 468 (10) ◽  
pp. 1709-1724 ◽  
Author(s):  
Jerzy A. Zoladz ◽  
Agnieszka Koziel ◽  
Andrzej Woyda-Ploszczyca ◽  
Jan Celichowski ◽  
Wieslawa Jarmuszkiewicz
Keyword(s):  
Skeletal Muscle ◽  
Endurance Training ◽  
Rat Skeletal Muscle ◽  
Muscle Mitochondria ◽  
Skeletal Muscle Mitochondria

scholarly journals Effect of fatty acids and ketones on the activity of pyruvate dehydrogenase in skeletal-muscle mitochondria

1983 ◽  
Vol 214 (3) ◽  
pp. 725-736 ◽  
Author(s):  
B Ashour ◽  
R G Hansford
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Cardiac Muscle ◽  
Pyruvate Dehydrogenase ◽  
Feedback Inhibition ◽  
Acetyl Coa ◽  
Muscle Mitochondria ◽  
Skeletal Muscle Mitochondria ◽  
Hind Limb Muscle ◽  
A Minor

The presence of palmitoyl-L-carnitine and acetoacetate (separately) decreased flux through pyruvate dehydrogenase in isolated mitochondria from rat hind-limb muscle. The effect of acetoacetate was dependent on the presence of 2-oxoglutarate and Ca2+. Palmitoylcarnitine, but not acetoacetate, also decreased the mitochondrial content of active dephospho-pyruvate dehydrogenase (PDHA). This effect was large only in the presence of EGTA. Addition of Ca2+-EGTA buffers stabilizing pCa values of 6.48 or lower gave near-maximal values of PDHA content, irrespective of the presence of fatty acids or ketones when mitochondria were incubated under the same conditions used for the flux studies, i.e. at low concentrations of pyruvate. There was, however, a minor decrement in PDHA content in response to palmitoylcarnitine oxidation when the substrate was L-glutamate plus L-malate. Measurement of NAD+, NADH, CoA and acetyl-CoA in mitochondrial extracts in general showed decreases in [NAD+]/[NADH] and [CoA]/[acetyl-CoA] ratios in response to the oxidation of palmitoylcarnitine and acetoacetate, providing a mechanism for both decreased PDHA content and feedback inhibition of the enzyme in the PDHA form. However, only changes in [CoA]/[acetyl-CoA] ratio appear to underlie the decreased PDHA content on addition of palmitoylcarnitine when mitochondria are incubated with L-glutamate plus L-malate (and no pyruvate) as substrate. The effect of palmitoylcarnitine oxidation on flux through pyruvate dehydrogenase and on PDHA content is less marked in skeletal-muscle mitochondria than in cardiac-muscle mitochondria. This may reflect the less active oxidation of palmitoylcarnitine by skeletal-muscle mitochondria, as judged by State-3 rates of O2 uptake. In addition, Ca2+ concentration is of even greater significance in pyruvate dehydrogenase interconversion in skeletal-muscle mitochondria than in cardiac-muscle mitochondria.

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