Determinants of maximal whole-body fat oxidation in elite cross-country skiers: Role of skeletal muscle mitochondria

2018 ◽  
Vol 28 (12) ◽  
pp. 2494-2504 ◽  
Author(s):  
Sune Dandanell ◽  
Anne-Kristine Meinild-Lundby ◽  
Andreas B. Andersen ◽  
Paul F. Lang ◽  
Laura Oberholzer ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Body Fat ◽  
Fat Oxidation ◽  
Whole Body ◽  
Muscle Mitochondria ◽  
Skeletal Muscle Mitochondria ◽  
Cross Country

scholarly journals Increasing skeletal muscle carnitine content in older individuals increases whole‐body fat oxidation during moderate‐intensity exercise

Aging Cell ◽  
2021 ◽  
Vol 20 (2) ◽  
Author(s):  
Carolyn Chee ◽  
Chris E. Shannon ◽  
Aisling Burns ◽  
Anna L. Selby ◽  
Daniel Wilkinson ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Body Fat ◽  
Fat Oxidation ◽  
Whole Body ◽  
Moderate Intensity ◽  
Older Individuals ◽  
Moderate Intensity Exercise

Reduced plasma FFA availability increases net triacylglycerol degradation, but not GPAT or HSL activity, in human skeletal muscle

2004 ◽  
Vol 287 (1) ◽  
pp. E120-E127 ◽  
Author(s):  
Matthew J. Watt ◽  
Anna G. Holmes ◽  
Gregory R. Steinberg ◽  
Jose L. Mesa ◽  
Bruce E. Kemp ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Body Fat ◽  
Plasma Free Fatty Acid ◽  
Fat Oxidation ◽  
Dry Mass ◽  
Hormone Sensitive Lipase ◽  
Whole Body ◽  
Plasma Ffa

Intramuscular triacylglycerols (IMTG) are proposed to be an important metabolic substrate for contracting muscle, although this remains controversial. To test the hypothesis that reduced plasma free fatty acid (FFA) availability would increase IMTG degradation during exercise, seven active men cycled for 180 min at 60% peak pulmonary O2 uptake either without (CON) or with (NA) prior ingestion of nicotinic acid to suppress adipose tissue lipolysis. Skeletal muscle and adipose tissue biopsy samples were obtained before and at 90 and 180 min of exercise. NA ingestion decreased ( P < 0.05) plasma FFA at rest and completely suppressed the exercise-induced increase in plasma FFA (180 min: CON, 1.42 ± 0.07; NA, 0.10 ± 0.01 mM). The decreased plasma FFA during NA was associated with decreased ( P < 0.05) adipose tissue hormone-sensitive lipase (HSL) activity (CON: 13.9 ± 2.5, NA: 9.1 ± 3.0 nmol·min−1·mg protein−1). NA ingestion resulted in decreased whole body fat oxidation and increased carbohydrate oxidation. Despite the decreased whole body fat oxidation, net IMTG degradation was greater in NA compared with CON (net change: CON, 2.3 ± 0.8; NA, 6.3 ± 1.2 mmol/kg dry mass). The increased IMTG degradation did not appear to be due to reduced fatty acid esterification, because glycerol 3-phosphate activity was not different between trials and was unaffected by exercise (rest: 0.21 ± 0.07; 180 min: 0.17 ± 0.04 nmol·min−1·mg protein−1). HSL activity was not increased from resting rates during exercise in either trial despite elevated plasma epinephrine, decreased plasma insulin, and increased ERK1/2 phosphorylation. AMP-activated protein kinase (AMPK)α1 activity was not affected by exercise or NA, whereas AMPKα2 activity was increased ( P < 0.05) from rest during exercise in NA and was greater ( P < 0.05) than in CON at 180 min. These data suggest that plasma FFA availability is an important mediator of net IMTG degradation, and in the absence of plasma FFA, IMTG degradation cannot maintain total fat oxidation. These changes in IMTG degradation appear to disassociate, however, from the activity of the key enzymes responsible for synthesis and degradation of this substrate.

scholarly journals Age-related changes in skeletal muscle mitochondria: the role of exercise

2016 ◽  
Vol 5 (3) ◽  
pp. 182-186 ◽  
Author(s):  
Dae Yun Seo ◽  
Sung Ryul Lee ◽  
Nari Kim ◽  
Kyung Soo Ko ◽  
Byoung Doo Rhee ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Mitochondria ◽  
Skeletal Muscle Mitochondria ◽  
Age Related ◽  
Age Related Changes

scholarly journals Associations of Mitochondrial Fatty Acid Oxidation with Body Fat in Premenopausal Women

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Jonathan L. Warren ◽  
Barbara A. Gower ◽  
Gary R. Hunter ◽  
Samuel T. Windham ◽  
Douglas R. Moellering ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acid ◽  
Body Fat ◽  
Fat Mass ◽  
Premenopausal Women ◽  
Muscle Mitochondria ◽  
Skeletal Muscle Mitochondria ◽  
Total Body Fat ◽  
Total Fat ◽  
Total Body

Higherin vivofatty acid (FA) oxidation rates have been reported in obese individuals compared to lean counterparts; however whether this reflects a shift in substrate-specific oxidative capacity at the level of the skeletal muscle mitochondria has not been examined. The purpose of this study was to test the hypothesis that in situ measures of skeletal muscle mitochondria FA oxidation would be positively associated with total body fat. Participants were 38 premenopausal women (BMI=26.5±4.3 kg/m2). Total and regional fat were assessed by dual-energy X-ray absorptiometry (DXA). Mitochondrial FA oxidation was assessed in permeabilized myofibers using high-resolution respirometry and a palmitoyl carnitine substrate. We found positive associations of total fat mass with State 3 (ADP-stimulated respiration) (r=0.379,p<0.05) and the respiratory control ratio (RCR, measure of mitochondrial coupling) (r=0.348,p<0.05). When participants were dichotomized by high or low body fat percent, participants with high total body fat displayed a higher RCR compared to those with low body fat (p<0.05). There were no associations between any measure of regional fat and mitochondrial FA oxidation independent of total fat mass. In conclusion, greater FA oxidation in obesity may reflect molecular processes that enhance FA oxidation capacity at the mitochondrial level.

Changes in Whole-Body Oxygen Consumption and Skeletal Muscle Mitochondria During Linezolid-Induced Lactic Acidosis

2016 ◽  
Vol 44 (7) ◽  
pp. e579-e582 ◽  
Author(s):  
Alessandro Protti ◽  
Dario Ronchi ◽  
Gabriele Bassi ◽  
Francesco Fortunato ◽  
Andreina Bordoni ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Oxygen Consumption ◽  
Lactic Acidosis ◽  
Whole Body ◽  
Muscle Mitochondria ◽  
Skeletal Muscle Mitochondria
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