Differences in metabolic response of dog and goat latissimus dorsi muscle to chronic stimulation

1992 ◽  
Vol 73 (3) ◽  
pp. 806-811 ◽  
Author(s):  
J. F. Glatz ◽  
Y. F. de Jong ◽  
W. A. Coumans ◽  
C. M. Lucas ◽  
F. H. van der Veen ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Latissimus Dorsi ◽  
Citrate Synthase ◽  
Metabolic Response ◽  
High Energy ◽  
Metabolic Adaptation ◽  
Acid Oxidation ◽  
Type I ◽  
High Energy Phosphates ◽  
Chronic Stimulation

The latissimus dorsi (LD) muscle is considered suitable to assist ventricular mechanical function in either cardiomyoplasty or extra-aortic-assist devices. Such application requires that this mixed-type skeletal muscle be transformed into a fatigue-resistant muscle, the adaptation of which can be elicited by chronic stimulation. In this study the LD muscles of dog and goat were subjected in situ to 12 wk of continuous electrical stimulation through intramuscular electrodes, and their myofibrillar and metabolic adaptations were compared. A gradual increase in the contraction rate of the muscle (in 10 wk from 30 to 80 contractions/min) caused the proportion of immunohistochemically identified type I fibers to increase in dog muscle from 30 to 74% and in goat muscle from 21 to 99%. Correspondingly, the anaerobic-glycolytic activity (fructose-6-phosphate kinase and lactate dehydrogenase activities) decreased by approximately 75% in both dog and goat muscles, whereas the oxidative capacity (fatty acid oxidation and citrate synthase activity) increased two- to threefold in goat LD muscle but remained unaltered in dog LD muscle. Muscular contents of high-energy phosphates and endogenous substrates were maintained, but the L-carnitine content decreased by 43% in both dog and goat. Our data further indicate that, for the monitoring of the metabolic adaptation of skeletal muscle, the ratio of activities of the oxidative and anaerobic-glycolytic pathways (e.g., citrate synthase to fructose-6-phosphate kinase activities) is a useful parameter in both dog and goat.(ABSTRACT TRUNCATED AT 250 WORDS)

NADH shuttle enzymes and cytochrome b5 reductase in human skeletal muscle: effect of strength training

1989 ◽  
Vol 67 (1) ◽  
pp. 123-127 ◽  
Author(s):  
P. G. Schantz ◽  
M. Kallman
Keyword(s):  
Skeletal Muscle ◽  
Strength Training ◽  
Human Skeletal Muscle ◽  
Citrate Synthase ◽  
Cytochrome B5 ◽  
Lower Percentage ◽  
Acid Oxidation ◽  
Type I ◽  
Marker Enzyme ◽  
Cytochrome B5 Reductase

The main aim of this study was to investigate whether enzyme levels of the malate-aspartate and alpha-glycerophosphate shuttles and of cytochrome b5 reductase in human skeletal muscle are affected by strength training. Muscle biopsy samples from the deltoid muscle of the nondominant arm in untrained (n = 12) and strength-trained (n = 12) subjects were compared. The strength-trained muscles were characterized by a tendency to a higher percentage of type I fibers (67 vs. 59%), a lower percentage of type IIb fibers (12 vs. 18%), 34% larger mean fiber areas, and 19% more capillaries per fiber (P less than 0.1). No difference was noted in levels of enzymes representing the citric acid cycle, fatty acid oxidation, and glycolysis, nor in the number of capillaries per square millimeter. Neither did the levels of malate-aspartate and alpha-glycerophosphate shuttle enzymes nor cytochrome b5 reductase differ. Levels of cytochrome b5 reductase correlated (r = 0.59, P less than 0.01) with levels of the mitochondrial marker enzyme citrate synthase. It is concluded that strength training does not appear to result in increased levels of NADH shuttle enzymes and cytochrome b5 reductase.

Anaerobic energy provision in aged skeletal muscle during tetanic stimulation

1991 ◽  
Vol 70 (4) ◽  
pp. 1787-1795 ◽  
Author(s):  
C. B. Campbell ◽  
D. R. Marsh ◽  
L. L. Spriet
Keyword(s):  
Skeletal Muscle ◽  
Energy Demand ◽  
Energy Charge ◽  
High Energy ◽  
High Energy Phosphates ◽  
Fischer 344 ◽  
Charge Potential ◽  
Anaerobic Energy ◽  
Gastrocnemius Muscles

The effect of age on skeletal muscle anaerobic energy metabolism was investigated in adult (11 mo) and aged (25 mo) Fischer 344 rats. Hindlimb skeletal muscles innervated by the sciatic nerve were stimulated to contract with trains of supramaximal impulses (100 ms, 80 Hz) at a train rate of 1 Hz for 60 s, with an occluded circulation. Soleus, plantaris, and red and white gastrocnemius (WG) were sampled from control and stimulated limbs. All muscle masses were reduced with age (9-13%). Peak isometric tensions, normalized per gram of wet muscle, were lower throughout the stimulation in the aged animals (28%). The potential for anaerobic ATP provision was unaltered with age in all muscles, because resting high-energy phosphates and glycogen contents were similar to adult values. Anaerobic ATP provision during stimulation was unaltered by aging in soleus, plantaris, and red gastrocnemius muscles. In the WG, containing mainly fast glycolytic (FG) fibers, ATP and phosphocreatine contents were depleted less in aged muscle. In situ glycogenolysis and glycolysis were 90.0 +/- 4.8 and 69.3 +/- 2.6 mumol/g dry muscle (dm) in adult WG and reduced to 62.3 +/- 6.9 and 51.5 +/- 5.5 mumol/g dm, respectively, in aged WG. Consequently, total anaerobic ATP provision was lower in aged WG (224.5 +/- 20.9 mumol/g dm) vs. adult (292.6 +/- 7.6 mumol/g dm) WG muscle. In summary, the decreased tetanic tension production in aged animals was associated with a decreased anaerobic energy production in FG fibers. Reduced high-energy phosphate use and a greater energy charge potential after stimulation suggested that the energy demand was reduced in aged FG fibers.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Selective overexpression of Toll-like receptor-4 in skeletal muscle impairs metabolic adaptation to high-fat feeding

2015 ◽  
Vol 309 (3) ◽  
pp. R304-R313 ◽  
Author(s):  
Ryan P. McMillan ◽  
Yaru Wu ◽  
Kevin Voelker ◽  
Gabrielle Fundaro ◽  
John Kavanaugh ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
High Fat Diet ◽  
Whole Body ◽  
Metabolic Adaptation ◽  
Acid Oxidation ◽  
Chow Diet ◽  
Toll Like Receptor ◽  
High Fat ◽  
Toll Like Receptor 4 ◽  
Fat Feeding

Toll-like receptor-4 (TLR-4) is elevated in skeletal muscle of obese humans, and data from our laboratory have shown that activation of TLR-4 in skeletal muscle via LPS results in decreased fatty acid oxidation (FAO). The purpose of this study was to determine whether overexpression of TLR-4 in skeletal muscle alters mitochondrial function and whole body metabolism in the context of a chow and high-fat diet. C57BL/6J mice (males, 6–8 mo of age) with skeletal muscle-specific overexpression of the TLR-4 (mTLR-4) gene were created and used for this study. Isolated mitochondria and whole muscle homogenates from rodent skeletal muscle (gastrocnemius and quadriceps) were investigated. TLR-4 overexpression resulted in a significant reduction in FAO in muscle homogenates; however, mitochondrial respiration and reactive oxygen species (ROS) production did not appear to be affected on a standard chow diet. To determine the role of TLR-4 overexpression in skeletal muscle in response to high-fat feeding, mTLR-4 mice and WT control mice were fed low- and high-fat diets for 16 wk. The high-fat diet significantly decreased FAO in mTLR-4 mice, which was observed in concert with elevated body weight and fat, greater glucose intolerance, and increase in production of ROS and cellular oxidative damage compared with WT littermates. These findings suggest that TLR-4 plays an important role in the metabolic response in skeletal muscle to high-fat feeding.

Fatty Acid Oxidation by Skeletal Muscle During Rest and Activity

1958 ◽  
Vol 194 (2) ◽  
pp. 379-386 ◽  
Author(s):  
Irving B. Fritz ◽  
Don G. Davis ◽  
Robert H. Holtrop ◽  
Harold Dundee
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acid ◽  
Palmitic Acid ◽  
Fatty Acid Oxidation ◽  
Latissimus Dorsi ◽  
Acid Metabolism ◽  
Fat Metabolism ◽  
Acid Oxidation ◽  
Stimulation Of

The metabolism of C14-labeled acetate, octanoate and palmitate by isolated skeletal muscle (latissimus dorsi and diaphragm) from normal, fed rats has been examined. The rates at which these substrates were converted to C14O2 have been shown to vary with concentration, temperature, functional state of the muscle, and the presence of albumin. Increased concentration of fatty acids led to enhanced conversion of substrate to C14O2. Electrical stimulation of muscles under tension resulted in approximately a 60% increase in oxygen consumption and about a 100% rise in fatty acid oxidation. The addition of glucose did not alter the rate of fatty acid metabolism by muscle. The addition of bovine albumin at concentrations up to approximately 1 µm albumin/7 µm palmitate resulted in augmented palmitic acid oxidation. However, at concentrations of albumin greater than 1 µm albumin/7 µm palmitate, palmitic acid degradation by resting diaphragm was inhibited, suggesting a firmer binding of fatty acid to albumin. The Q10 for palmitic acid oxidation by resting diaphragm was 2.23 in the absence of added albumin between 25° and 37°C. The data are discussed in relation to the present concepts of fat metabolism and transport in vivo. It is suggested that fat degradation in isolated muscle may provide an energy source during activity.

Contractile and metabolic effects of increased creatine kinase activity in mouse skeletal muscle

1996 ◽  
Vol 270 (4) ◽  
pp. C1236-C1245 ◽  
Author(s):  
B. B. Roman ◽  
J. M. Foley ◽  
R. A. Meyer ◽  
A. P. Koretsky
Keyword(s):  
Skeletal Muscle ◽  
Creatine Kinase ◽  
Kinase Activity ◽  
Contractile Function ◽  
Contractile Activity ◽  
High Energy ◽  
Metabolic Effects ◽  
High Energy Phosphates ◽  
Lactate Dehydrogenase Activity ◽  
B Subunit

The effects of increased expression of creatine kinase (CK) in skeletal muscle were studied in control and transgenic animals homozygous for expression of the B subunit of CK. CK activity was 47% higher in transgenic gastrocnemius muscle. The CK activity was distributed as follows: 45 +/- 1% MM dinner, 31 +/- 4% MB dimer, and 22 +/- 5% BB dimer. No significant differences in metabolic or contractile proteins were detected except for a 22% decrease in lactate dehydrogenase activity and a 9% decrease in adenylate kinase activity. The only significant effect in contractile activity was that the rise time of a 5-s isometric contraction was 28% faster in the transgenic muscle. 31P nuclear magnetic resonance (NMR) spectra were obtained from control and transgenic muscles during mechanical activation, and there were no NMR measurable differences detected. These results indicate that a 50% increase in CK activity due to expression of the B subunit does not have large effects on skeletal muscle metabolism or contractile function. Therefore, control muscle has sufficient CK activity to keep up with changes in cellular high-energy phosphates except during the early phase of intense contractile activity.

scholarly journals Overexpression of TRB3 in muscle alters muscle fiber type and improves exercise capacity in mice

2014 ◽  
Vol 306 (12) ◽  
pp. R925-R933 ◽  
Author(s):  
Ding An ◽  
Sarah J. Lessard ◽  
Taro Toyoda ◽  
Min-Young Lee ◽  
Ho-Jin Koh ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Exercise Capacity ◽  
Muscle Fiber ◽  
Wheel Running ◽  
Fiber Type ◽  
Muscle Fiber Type ◽  
Acid Oxidation ◽  
Peroxisome Proliferator ◽  
Type I ◽  
Pronounced Increase

Increasing evidence suggests that TRB3, a mammalian homolog of Drosophila tribbles, plays an important role in cell growth, differentiation, and metabolism. In the liver, TRB3 binds and inhibits Akt activity, whereas in adipocytes, TRB3 upregulates fatty acid oxidation. In cultured muscle cells, TRB3 has been identified as a potential regulator of insulin signaling. However, little is known about the function and regulation of TRB3 in skeletal muscle in vivo. In the current study, we found that 4 wk of voluntary wheel running (6.6 ± 0.4 km/day) increased TRB3 mRNA by 1.6-fold and protein by 2.5-fold in the triceps muscle. Consistent with this finding, muscle-specific transgenic mice that overexpress TRB3 (TG) had a pronounced increase in exercise capacity compared with wild-type (WT) littermates (TG: 1,535 ± 283; WT: 644 ± 67 joules). The increase in exercise capacity in TRB3 TG mice was not associated with changes in glucose uptake or glycogen levels; however, these mice displayed a dramatic shift toward a more oxidative/fatigue-resistant (type I/IIA) muscle fiber type, including threefold more type I fibers in soleus muscles. Skeletal muscle from TRB3 TG mice had significantly decreased PPARα expression, twofold higher levels of miR208b and miR499, and corresponding increases in the myosin heavy chain isoforms Myh7 and Myb7b, which encode these microRNAs. These findings suggest that TRB3 regulates muscle fiber type via a peroxisome proliferator-activated receptor-α (PPAR-α)-regulated miR499/miR208b pathway, revealing a novel function for TRB3 in the regulation of skeletal muscle fiber type and exercise capacity.

scholarly journals Redox state and lactate accumulation in human skeletal muscle during dynamic exercise

1987 ◽  
Vol 245 (2) ◽  
pp. 551-556 ◽  
Author(s):  
K Sahlin ◽  
A Katz ◽  
J Henriksson
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Redox State ◽  
Lactate Production ◽  
High Energy ◽  
High Energy Phosphates ◽  
Vo2 Max ◽  
Muscle Lactate ◽  
Lactate Accumulation ◽  
Pyruvate Ratio

The relationship between the redox state and lactate accumulation in contracting human skeletal muscle was investigated. Ten men performed bicycle exercise for 10 min at 40 and 75% of maximal oxygen uptake [VO2(max.)], and to fatigue (4.8 +/- 0.6 min; mean +/- S.E.M.) at 100% VO2(max.). Biopsies from the quadriceps femoris muscle were analysed for NADH, high-energy phosphates and glycolytic intermediates. Muscle NADH was 0.20 +/- 0.02 mmol/kg dry wt. of muscle at rest, and decreased to 0.12 +/- 0.01 (P less than 0.01) after exercise at 40% VO2(max.), but no change occurred in the [lactate]/[pyruvate] ratio. These data, together with previous results on isolated cyanide-poisoned soleus muscle, where NADH increased while [lactate]/[pyruvate] ratio was unchanged [Sahlin & Katz (1986) Biochem. J. 239, 245-248], suggest that the observed changes in muscle NADH occurred within the mitochondria. After exercise at 75 and 100% VO2(max.), muscle NADH increased above the value at rest to 0.27 +/- 0.03 (P less than 0.05) and 0.32 +/- 0.04 (P less than 0.001) mmol/kg respectively. Muscle lactate was unchanged after exercise at 40% VO2(max.), but increased substantially at the higher work loads. At 40% VO2(max.), phosphocreatine decreased by 11% compared with the values at rest, and decreased further at the higher work loads. The decrease in phosphocreatine reflects increased ADP and Pi. It is concluded that muscle NADH decreases during low-intensity exercise, but increases above the value at rest during high-intensity exercise. The increase in muscle NADH is consistent with the hypothesis that the accelerated lactate production during submaximal exercise is due to a limited availability of O2 in the contracting muscle. It is suggested that the increases in NADH, ADP and Pi are metabolic adaptations, which primarily serve to activate the aerobic ATP production, and that the increased anaerobic energy production (phosphocreatine breakdown and lactate formation) is a consequence of these changes.

Randomized trial of progressive resistance training to counteract the myopathy of chronic heart failure

2001 ◽  
Vol 90 (6) ◽  
pp. 2341-2350 ◽  
Author(s):  
Charles T. Pu ◽  
Meredith T. Johnson ◽  
Daniel E. Forman ◽  
Jeffrey M. Hausdorff ◽  
Ronenn Roubenoff ◽  
...  
Keyword(s):  
Heart Failure ◽  
Skeletal Muscle ◽  
Chronic Heart Failure ◽  
Resistance Training ◽  
Older Women ◽  
Citrate Synthase ◽  
Type I ◽  
Progressive Resistance Training ◽  
Walk Distance ◽  
Progressive Resistance

Chronic heart failure (CHF) is characterized by a skeletal muscle myopathy not optimally addressed by current treatment paradigms or aerobic exercise. Sixteen older women with CHF were compared with 80 age-matched peers without CHF and randomized to progressive resistance training or control stretching exercises for 10 wk. Women with CHF had significantly lower muscle strength ( P < 0.0001) but comparable aerobic capacity to women without CHF. Exercise training was well tolerated and resulted in no changes in resting cardiac indexes in CHF patients. Strength improved by an average of 43.4 ± 8.8% in resistance trainers vs. −1.7 ± 2.8% in controls ( P = 0.001), muscle endurance by 299 ± 66% vs. 1 ± 3% ( P = 0.001), and 6-min walk distance by 49 ± 14 m (13%) vs. −3 ± 19 m (−3%) ( P = 0.03). Increases in type I fiber area (9.5 ± 16%) and citrate synthase activity (35 ± 21%) in skeletal muscle were independently predictive of improved 6-min walk distance ( r 2 = 0.78; P = 0.0024). High-intensity progressive resistance training improves impaired skeletal muscle characteristics and overall exercise performance in older women with CHF. These gains are largely explained by skeletal muscle and not resting cardiac adaptations.

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