scholarly journals Adaptation of mitochondrial ATP production in human skeletal muscle to endurance training and detraining

1992 ◽  
Vol 73 (5) ◽  
pp. 2004-2010 ◽  
Author(s):  
R. Wibom ◽  
E. Hultman ◽  
M. Johansson ◽  
K. Matherei ◽  
D. Constantin-Teodosiu ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cytochrome C ◽  
Endurance Training ◽  
Enzyme Activities ◽  
Citrate Synthase ◽  
Mitochondrial Fraction ◽  
Mitochondrial Enzyme ◽  
Atp Production ◽  
Before And After ◽  
Training And Detraining

The adaptation of mitochondrial ATP production rate (MAPR) to training and detraining was evaluated in nine healthy men. Muscle samples (approximately 60 mg) were obtained before and after 6 wk of endurance training and after 3 wk of detraining. MAPR was measured in isolated mitochondria by a bioluminometric method. In addition, the activities of mitochondrial and glycolytic enzymes were determined in skeletal muscle. In response to training, MAPR increased by 70%, with a substrate combination of pyruvate + palmitoyl-L-carnitine + alpha-ketoglutarate + malate, by 50% with only pyruvate + malate, and by 92% with palmitoyl-L-carnitine + malate. With detraining MAPR decreased by 12–28% from the posttraining rate (although not significantly for all substrates). No differences were found when MAPR was related to the protein content in the mitochondrial fraction. The largest increase in mitochondrial enzyme activities induced by training was observed for cytochrome-c oxidase (78%), whereas succinate cytochrome c reductase showed only an 18% increase. The activity of citrate synthase increased by 40% and of glutamate dehydrogenase by 45%. Corresponding changes in maximal O2 uptake were a 9.6% increase by training and a 6.0% reversion after detraining. In conclusion, both MAPR and mitochondrial enzyme activities are shown to increase with endurance training and to decrease with detraining.

The relationship between human skeletal muscle pyruvate dehydrogenase phosphatase activity and muscle aerobic capacity

2011 ◽  
Vol 111 (2) ◽  
pp. 427-434 ◽  
Author(s):  
Lorenzo K. Love ◽  
Paul J. LeBlanc ◽  
J. Greig Inglis ◽  
Nicolette S. Bradley ◽  
Jon Choptiany ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Content ◽  
Endurance Training ◽  
Aerobic Capacity ◽  
Pyruvate Dehydrogenase ◽  
Human Skeletal Muscle ◽  
Citrate Synthase ◽  
Tricarboxylic Acid Cycle ◽  
Carbohydrate Oxidation ◽  
Pyruvate Dehydrogenase Phosphatase

Pyruvate dehydrogenase (PDH) is a mitochondrial enzyme responsible for regulating the conversion of pyruvate to acetyl-CoA for use in the tricarboxylic acid cycle. PDH is regulated through phosphorylation and inactivation by PDH kinase (PDK) and dephosphorylation and activation by PDH phosphatase (PDP). The effect of endurance training on PDK in humans has been investigated; however, to date no study has examined the effect of endurance training on PDP in humans. Therefore, the purpose of this study was to examine differences in PDP activity and PDP1 protein content in human skeletal muscle across a range of muscle aerobic capacities. This association is important as higher PDP activity and protein content will allow for increased activation of PDH, and carbohydrate oxidation. The main findings of this study were that 1) PDP activity ( r2 = 0.399, P = 0.001) and PDP1 protein expression ( r2 = 0.153, P = 0.039) were positively correlated with citrate synthase (CS) activity as a marker for muscle aerobic capacity; 2) E1α ( r2 = 0.310, P = 0.002) and PDK2 protein ( r2 = 0.229, P =0.012) are positively correlated with muscle CS activity; and 3) although it is the most abundant isoform, PDP1 protein content only explained ∼18% of the variance in PDP activity ( r2 = 0.184, P = 0.033). In addition, PDP1 in combination with E1α explained ∼38% of the variance in PDP activity ( r2 = 0.383, P = 0.005), suggesting that there may be alternative regulatory mechanisms of this enzyme other than protein content. These data suggest that with higher muscle aerobic capacity (CS activity) there is a greater capacity for carbohydrate oxidation (E1α), in concert with higher potential for PDH activation (PDP activity).

Regulation of muscle glycogen phosphorylase activity following short-term endurance training

1996 ◽  
Vol 270 (2) ◽  
pp. E328-E335 ◽  
Author(s):  
A. Chesley ◽  
G. J. Heigenhauser ◽  
L. L. Spriet
Keyword(s):  
Endurance Training ◽  
Muscle Glycogen ◽  
Glycogen Phosphorylase ◽  
Citrate Synthase ◽  
Phosphorylase Activity ◽  
Short Term ◽  
Mitochondrial Potential ◽  
Before And After ◽  
Glycogen Phosphorylase Activity ◽  
Muscle Biopsies

The purpose of this study was to examine the regulation (hormonal, substrate, and allosteric) of muscle glycogen phosphorylase (Phos) activity and glycogenolysis after short-term endurance training. Eight untrained males completed 6 days of cycle exercise (2 h/day) at 65% of maximal O2 uptake (Vo2max). Before and after training subjects cycled for 15 min at 80% of Vo2max, and muscle biopsies and blood samples were obtained at 0 and 30 s, 7.5 and 15 min, and 0, 5, 10, and 15 min of exercise. Vo2max was unchanged with training but citrate synthase (CS) activity increased by 20%. Muscle glycogenolysis was reduced by 42% during the 15-min exercise challenge following training (198.8 +/- 36.9 vs. 115.4 +/- 25.1 mmol/kg dry muscle), and plasma epinephrine was blunted at 15 min of exercise. The Phos a mole fraction was unaffected by training. Muscle phosphocreatine utilization and free Pi and AMP accumulations were reduced with training at 7.5 and 15 min of exercise. It is concluded that posttransformational control of Phos, exerted by reductions in substrate (free Pi) and allosteric modulator (free AMP) contents, is responsible for a blunted muscle glycogenolysis after 6 days of endurance training. The increase in CS activity suggests that the reduction of muscle glycogenolysis was due in part to an enhanced mitochondrial potential.

T3 increases mitochondrial ATP production in oxidative muscle despite increased expression of UCP2 and -3

2001 ◽  
Vol 280 (5) ◽  
pp. E761-E769 ◽  
Author(s):  
Kevin R. Short ◽  
Jonas Nygren ◽  
Rocco Barazzoni ◽  
James Levine ◽  
K. Sreekumaran Nair
Keyword(s):  
Skeletal Muscle ◽  
Citrate Synthase ◽  
Atp Synthesis ◽  
Nutrient Flux ◽  
Oxidative Enzymes ◽  
Mrna Levels ◽  
Plantaris Muscle ◽  
Atp Production ◽  
Protein Levels ◽  
Different Types

Triiodothyronine (T3) increases O2 and nutrient flux through mitochondria (Mito) of many tissues, but it is unclear whether ATP synthesis is increased, particularly in different types of skeletal muscle, because variable changes in uncoupling proteins (UCP) and enzymes have been reported. Thus Mito ATP production was measured in oxidative and glycolytic muscles, as well as in liver and heart, in rats administered T3 for 14 days. Relative to saline-treated controls, T3 rats had 80, 168, and 62% higher ATP production in soleus muscle, liver, and heart, respectively, as well as higher activities of citrate synthase (CS; 63, 90, 25%) and cytochrome c oxidase (COX; 119, 225, 52%) in the same tissues (all P < 0.01). In plantaris muscle of T3 rats, CS was only slightly higher (17%, P < 0.05) than in controls, and ATP production and COX were unaffected. mRNA levels of COX I and III were 33 and 47% higher in soleus of T3 rats ( P < 0.01), but there were no differences in plantaris. In contrast, UCP2 and -3 mRNAs were 2.5- to 14-fold higher, and protein levels were 3- to 10-fold higher in both plantaris and soleus of the T3 group. We conclude that T3 increases oxidative enzymes and Mito ATP production and Mito-encoded transcripts in oxidative but not glycolytic rodent tissues. Despite large increases in UCP expression, ATP production was enhanced in oxidative tissues and maintained in glycolytic muscle of hyperthyroid rats.

Muscle enzyme adaptations to added load during training and nontraining hours in rats

1991 ◽  
Vol 70 (2) ◽  
pp. 764-769 ◽  
Author(s):  
H. Rusko ◽  
C. Bosco ◽  
J. Komulainen ◽  
A. Leinonen ◽  
V. Vihko
Keyword(s):  
Creatine Kinase ◽  
Endurance Training ◽  
Dehydrogenase Activity ◽  
Malate Dehydrogenase ◽  
Enzyme Activities ◽  
Citrate Synthase ◽  
Effective Means ◽  
Sedentary Control ◽  
Muscle Enzyme ◽  
Gastrocnemius Muscles

The effects of added load (20% of body mass) on the selected enzyme activities of red and white quadriceps femoris (QF), soleus, and gastrocnemius muscles of rats were studied. The rats were divided into sedentary control (SC), sedentary control with added load (SC+AL), endurance training (ET), and endurance training with added load (ET+AL) groups (n = 10 rats/group). After 6 wk, the SC+AL group had 57% higher (P less than 0.001) beta-glucuronidase (beta-GU) activity and 24% lower (P less than 0.05) citrate synthase activity in white QF than SC. Citrate synthase activity was also decreased in red QF (P less than 0.05) after the added load was used during nontraining hours. The training with added load induced similar but more pronounced changes than normal endurance training, especially in white QF. The ET+AL group demonstrated higher citrate synthase activity in white QF (P less than 0.001) and gastrocnemius (P less than 0.01) and higher malate dehydrogenase activity (P less than 0.05) and beta-GU activity (P less than 0.001) in white QF than the ET group. ET+AL rats also had higher phosphofructokinase (P less than 0.01) and lower creatine kinase (P less than 0.001) activity in white QF than ET rats. In conclusion, the added load without training had minor adaptive influences on muscles. The added load during training hours seemed to be an effective means of influencing the activation and adaptation in muscles that contain fast glycolytic fibers.

scholarly journals Effect of short-term training on mitochondrial ATP production rate in human skeletal muscle

1999 ◽  
Vol 86 (2) ◽  
pp. 450-454 ◽  
Author(s):  
Emma C. Starritt ◽  
Damien Angus ◽  
Mark Hargreaves
Keyword(s):  
Glutamate Dehydrogenase ◽  
Production Rate ◽  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Muscle Sample ◽  
Atp Production ◽  
Exercise Training Program ◽  
Before And After ◽  
Resting Muscle ◽  
Total Muscle

Seven untrained volunteers [3 men, 4 women, 20.1 ± 2.0 (SD) yr, 66.0 ± 11.0 kg, 171 ± 13 cm] participated in a 10-day cycle exercise training program. Resting muscle samples were obtained from vastus lateralis before and after 5 and 10 days of training. Mitochondrial ATP production rate (MAPR) was assayed in isolated mitochondria by using a bioluminescence technique and referenced to the activity of glutamate dehydrogenase in the muscle sample. MAPR increased 136 and 161% after 10 days of training for the mitochondrial substrate combinations pyruvate + palmitoyl-l-carnitine + α-ketoglutarate + malate and palmitoyl-l-carnitine + malate, respectively. Total muscle glutamate dehydrogenase and citrate synthase activity increased 53 and 16%, respectively, after 5 days but did not significantly increase further after 10 days. The results from the present study indicate that MAPR, measured by using the substrate combinations pyruvate + palmitoyl-l-carnitine + α-ketoglutarate + malate and palmitoyl-l-carnitine + malate, can rapidly increase in response to endurance training.

Effects of 7 wk of endurance training on human skeletal muscle metabolism during submaximal exercise

2004 ◽  
Vol 97 (6) ◽  
pp. 2148-2153 ◽  
Author(s):  
Paul J. LeBlanc ◽  
Krista R. Howarth ◽  
Martin J. Gibala ◽  
George J. F. Heigenhauser
Keyword(s):  
Skeletal Muscle ◽  
Endurance Training ◽  
Glycogen Phosphorylase ◽  
Human Skeletal Muscle ◽  
Vastus Lateralis ◽  
Muscle Metabolism ◽  
Allosteric Modulators ◽  
Before And After ◽  
First Time ◽  
Muscle Biopsies

This is the first study to examine the effects of endurance training on the activation state of glycogen phosphorylase (Phos) and pyruvate dehydrogenase (PDH) in human skeletal muscle during exercise. We hypothesized that 7 wk of endurance training (Tr) would result in a posttransformationally regulated decrease in flux through Phos and an attenuated activation of PDH during exercise due to alterations in key allosteric modulators of these important enzymes. Eight healthy men (22 ± 1 yr) cycled to exhaustion at the same absolute workload (206 ± 5 W; ∼80% of initial maximal oxygen uptake) before and after Tr. Muscle biopsies (vastus lateralis) were obtained at rest and after 5 and 15 min of exercise. Fifteen minutes of exercise post-Tr resulted in an attenuated activation of PDH (pre-Tr: 3.75 ± 0.48 vs. post-Tr: 2.65 ± 0.38 mmol·min−1·kg wet wt−1), possibly due in part to lower pyruvate content (pre-Tr: 0.94 ± 0.14 vs. post-Tr: 0.46 ± 0.03 mmol/kg dry wt). The decreased pyruvate availability during exercise post-Tr may be due to a decreased muscle glycogenolytic rate (pre-Tr: 13.22 ± 1.01 vs. post-Tr: 7.36 ± 1.26 mmol·min−1·kg dry wt−1). Decreased glycogenolysis was likely mediated, in part, by posttransformational regulation of Phos, as evidenced by smaller net increases in calculated muscle free ADP (pre-Tr: 111 ± 16 vs. post-Tr: 84 ± 10 μmol/kg dry wt) and Pi (pre-Tr: 57.1 ± 7.9 vs. post-Tr: 28.6 ± 5.6 mmol/kg dry wt). We have demonstrated for the first time that several signals act to coordinately regulate Phos and PDH, and thus carbohydrate metabolism, in human skeletal muscle after 7 wk of endurance training.

scholarly journals Altered glycolytic and oxidative capacities of skeletal muscle contribute to insulin resistance in NIDDM

1997 ◽  
Vol 83 (1) ◽  
pp. 166-171 ◽  
Author(s):  
Jean-Aimé Simoneau ◽  
David E. Kelley
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Enzyme Activities ◽  
Glycolytic Enzymes ◽  
Oxidative Enzyme ◽  
Oxidative Enzymes ◽  
Glucose Tolerant

Simoneau, Jean-Aimé, and David E. Kelley. Altered glycolytic and oxidative capacities of skeletal muscle contribute to insulin resistance in NIDDM. J. Appl. Physiol. 83(1): 166–171, 1997.—The insulin resistance of skeletal muscle in glucose-tolerant obese individuals is associated with reduced activity of oxidative enzymes and a disproportionate increase in activity of glycolytic enzymes. Because non-insulin-dependent diabetes mellitus (NIDDM) is a disorder characterized by even more severe insulin resistance of skeletal muscle and because many individuals with NIDDM are obese, the present study was undertaken to examine whether decreased oxidative and increased glycolytic enzyme activities are also present in NIDDM. Percutaneous biopsy of vatus lateralis muscle was obtained in eight lean (L) and eight obese (O) nondiabetic subjects and in eight obese NIDDM subjects and was assayed for marker enzymes of the glycolytic [phosphofructokinase, glyceraldehyde phosphate dehydrogenase, hexokinase (HK)] and oxidative pathways [citrate synthase (CS), cytochrome- c oxidase], as well as for a glycogenolytic enzyme (glycogen phosphorylase) and a marker of anaerobic ATP resynthesis (creatine kinase). Insulin sensitivity was measured by using the euglycemic clamp technique. Activity for glycolytic enzymes (phosphofructokinase, glyceraldehye phosphate dehydrogenase, HK) was highest in subjects with subjects with NIDDM, following the order of NIDDM > O > L, whereas maximum velocity for oxidative enzymes (CS, cytochrome- c oxidase) was lowest in subjects with NIDDM. The ratio between glycolytic and oxidative enzyme activities within skeletal muscle correlated negatively with insulin sensitivity. The HK/CS ratio had the strongest correlation ( r = −0.60, P < 0.01) with insulin sensitivity. In summary, an imbalance between glycolytic and oxidative enzyme capacities is present in NIDDM subjects and is more severe than in obese or lean glucose-tolerant subjects. The altered ratio between glycolytic and oxidative enzyme activities found in skeletal muscle of individuals with NIDDM suggests that a dysregulation between mitochondrial oxidative capacity and capacity for glycolysis is an important component of the expression of insulin resistance.

scholarly journals Effect of exercise training on metabolic flexibility in response to a high-fat diet in obese individuals

2012 ◽  
Vol 303 (12) ◽  
pp. E1440-E1445 ◽  
Author(s):  
Gina M. Battaglia ◽  
Donghai Zheng ◽  
Robert C. Hickner ◽  
Joseph A. Houmard
Keyword(s):  
Skeletal Muscle ◽  
Exercise Training ◽  
High Fat Diet ◽  
Citrate Synthase ◽  
Dietary Lipid ◽  
Acid Oxidation ◽  
Metabolic Flexibility ◽  
High Fat ◽  
Before And After ◽  
Obese Subjects

Obese individuals typically exhibit a reduced capacity for metabolic flexibility by failing to increase fatty acid oxidation (FAO) upon the imposition of a high-fat diet (HFD). Exercise training increases FAO in the skeletal muscle of obese individuals, but whether this intervention can restore metabolic flexibility is unclear. The purpose of this study was to compare FAO in the skeletal muscle of lean and obese subjects in response to a HFD before and after exercise training. Twelve lean (means ± SE) (age 21.8 ± 1.1 yr, BMI 22.6 ± 0.7 kg/m2) and 10 obese men (age 22.4 ± 0.8 yr, BMI 33.7 ± 0.7 kg/m2) consumed a eucaloric HFD (70% of energy from fat) for 3 days. After a washout period, 10 consecutive days of aerobic exercise (1 h/day, 70% V̇o2peak) were performed, with the HFD repeated during days 8–10. FAO and indices of mitochondrial content were determined from muscle biopsies. In response to the HFD, lean subjects increased complete FAO (27.3 ± 7.4%, P = 0.03) in contrast to no change in their obese counterparts (1.0 ± 7.9%). After 7 days of exercise, citrate synthase activity and FAO increased ( P < 0.05) regardless of body habitus; addition of the HFD elicited no further increase in FAO. These data indicate that obese, in contrast to lean, individuals do not increase FAO in skeletal muscle in response to a HFD. The increase in FAO with exercise training, however, enables the skeletal muscle of obese individuals to respond similarly to their lean counterparts when confronted with short-term excursion in dietary lipid.

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