Changes in Na+, K+-adenosinetriphosphatase, citrate synthase and K+ in sheep skeletal muscle during immobilization and remobilization

1995 ◽  
Vol 71 (5) ◽  
pp. 386-395 ◽  
Author(s):  
E. Jebens ◽  
H. Steen ◽  
T. O. Fjeld ◽  
E. Bye ◽  
O. M. Sejersted
Keyword(s):  
Skeletal Muscle ◽  
Citrate Synthase

Curcumin induces mitochondrial biogenesis by increasing cAMP levels via PDE4A inhibition in skeletal muscle

2021 ◽  
pp. 1-34
Author(s):  
Hamidie Ronald D Ray ◽  
Tsubasa Shibaguchi ◽  
Tatsuya Yamada ◽  
Rikuhide Koma ◽  
Rie Ishizawa ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Expression ◽  
Mitochondrial Biogenesis ◽  
Mitochondrial Respiration ◽  
Citrate Synthase ◽  
Signalling Pathway ◽  
Curcumin Treatment ◽  
Camp Content ◽  
Signalling Molecules ◽  
Camp Levels

Abstract Background: Previous research has suggested that curcumin potentially induces mitochondrial biogenesis in skeletal muscle via increasing cAMP levels. However, the regulatory mechanisms for this phenomenon remain unknown. The purpose of the present study was to clarify the mechanism by which curcumin activates cAMP-related signalling pathways that upregulate mitochondrial biogenesis and respiration in skeletal muscle. Methods: The effect of curcumin treatment (i.p., 100 mg/kg-BW/day for 28 days) on mitochondrial biogenesis was determined in rats. The effects of curcumin and exercise (swimming for 2 h/day for 3 days) on the cAMP signalling pathway were determined in the absence and presence of phosphodiesterase (PDE) or protein kinase A (PKA) inhibitors. Mitochondrial respiration, citrate synthase (CS) activity, cAMP content, and protein expression of cAMP/PKA signalling molecules were analysed. Results: Curcumin administration increased COX-IV protein expression, and CS and complex I activity, consistent with the induction of mitochondrial biogenesis by curcumin. Mitochondrial respiration was not altered by curcumin treatment. Curcumin and PDE inhibition tended to increase cAMP levels with or without exercise. In addition, exercise increased the phosphorylation of PDE4A, whereas curcumin treatment strongly inhibited PDE4A phosphorylation regardless of exercise. Furthermore, curcumin promoted AMPK phosphorylation and PGC-1α deacetylation. Inhibition of PKA abolished the phosphorylation of AMPK. Conclusion: The present results suggest that curcumin increases cAMP levels via inhibition of PDE4A phosphorylation, which induces mitochondrial biogenesis through a cAMP/PKA/AMPK signalling pathway. Our data also suggest the possibility that curcumin utilizes a regulatory mechanism for mitochondrial biogenesis that is distinct from the exercise-induced mechanism in skeletal muscle.

scholarly journals Atorvastatin impairs liver mitochondrial function in obese Göttingen Minipigs but heart and skeletal muscle are not affected

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Liselotte Bruun Christiansen ◽  
Tine Lovsø Dohlmann ◽  
Trine Pagh Ludvigsen ◽  
Ewa Parfieniuk ◽  
Michal Ciborowski ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mitochondrial Function ◽  
Citrate Synthase ◽  
Obese Group ◽  
Control Group ◽  
Dependent Manner ◽  
Respiratory Capacity ◽  
Protein Carbonyl Content ◽  
Functional Changes ◽  
Mitochondrial Respiratory

AbstractStatins lower the risk of cardiovascular events but have been associated with mitochondrial functional changes in a tissue-dependent manner. We investigated tissue-specific modifications of mitochondrial function in liver, heart and skeletal muscle mediated by chronic statin therapy in a Göttingen Minipig model. We hypothesized that statins enhance the mitochondrial function in heart but impair skeletal muscle and liver mitochondria. Mitochondrial respiratory capacities, citrate synthase activity, coenzyme Q10 concentrations and protein carbonyl content (PCC) were analyzed in samples of liver, heart and skeletal muscle from three groups of Göttingen Minipigs: a lean control group (CON, n = 6), an obese group (HFD, n = 7) and an obese group treated with atorvastatin for 28 weeks (HFD + ATO, n = 7). Atorvastatin concentrations were analyzed in each of the three tissues and in plasma from the Göttingen Minipigs. In treated minipigs, atorvastatin was detected in the liver and in plasma. A significant reduction in complex I + II-supported mitochondrial respiratory capacity was seen in liver of HFD + ATO compared to HFD (P = 0.022). Opposite directed but insignificant modifications of mitochondrial respiratory capacity were seen in heart versus skeletal muscle in HFD + ATO compared to the HFD group. In heart muscle, the HFD + ATO had significantly higher PCC compared to the HFD group (P = 0.0323). In the HFD group relative to CON, liver mitochondrial respiration decreased whereas in skeletal muscle, respiration increased but these changes were insignificant when normalizing for mitochondrial content. Oral atorvastatin treatment in Göttingen Minipigs is associated with a reduced mitochondrial respiratory capacity in the liver that may be linked to increased content of atorvastatin in this organ.

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).

Exercise training increases branched-chain oxoacid dehydrogenase kinase content in human skeletal muscle

2007 ◽  
Vol 293 (3) ◽  
pp. R1335-R1341 ◽  
Author(s):  
Krista R. Howarth ◽  
Kirsten A. Burgomaster ◽  
Stuart M. Phillips ◽  
Martin J. Gibala
Keyword(s):  
Skeletal Muscle ◽  
Exercise Training ◽  
Protein Content ◽  
Human Skeletal Muscle ◽  
Acute Exercise ◽  
Citrate Synthase ◽  
Muscle Protein ◽  
Moderate Intensity ◽  
Main Effect ◽  
Branched Chain

The branched-chain oxoacid dehydrogenase complex (BCOAD) is rate determining for the oxidation of branched-chain amino acids (BCAAs) in skeletal muscle. Exercise training blunts the acute exercise-induced activation of BCOAD (BCOADa) in human skeletal muscle (McKenzie S, Phillips SM, Carter SL, Lowther S, Gibala MJ, Tarnopolsky MA. Am J Physiol Endocrinol Metab 278: E580–E587, 2000); however, the mechanism is unknown. We hypothesized that training would increase the muscle protein content of BCOAD kinase, the enzyme responsible for inactivation of BCOAD by phosphorylation. Twenty subjects [23 ± 1 yr; peak oxygen uptake (V̇o2peak) = 41 ± 2 ml·kg−1·min−1] performed 6 wk of either high-intensity interval or continuous moderate-intensity training on a cycle ergometer ( n = 10/group). Before and after training, subjects performed 60 min of cycling at 65% of pretraining V̇o2peak, and needle biopsy samples (vastus lateralis) were obtained before and immediately after exercise. The effect of training was demonstrated by an increased V̇o2peak, increased citrate synthase maximal activity, and reduced muscle glycogenolysis during exercise, with no difference between groups (main effects, P < 0.05). BCOADa was lower after training (main effect, P < 0.05), and this was associated with a ∼30% increase in BCOAD kinase protein content (main effect, P < 0.05). We conclude that the increased protein content of BCOAD kinase may be involved in the mechanism for reduced BCOADa after exercise training in human skeletal muscle. These data also highlight differences in models used to study the regulation of skeletal muscle BCAA metabolism, since exercise training was previously reported to increase BCOADa during exercise and decrease BCOAD kinase content in rats (Fujii H, Shimomura Y, Murakami T, Nakai N, Sato T, Suzuki M, Harris RA. Biochem Mol Biol Int 44: 1211–1216, 1998).

241 Skeletal Muscle Mitochondrial Capacities Are Impacted by Breed and Temperament in Young Angus and Brahman Steers

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 127-127
Author(s):  
Chloey P Guy ◽  
Lauren T Wesolowski ◽  
Audrey L Earnhardt ◽  
Dustin Law ◽  
Don A Neuendorff ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fixed Effects ◽  
Linear Models ◽  
Citrate Synthase ◽  
Volume Density ◽  
Skeletal Muscle Mitochondria ◽  
Mitochondrial Volume ◽  
Mitochondrial Volume Density ◽  
Brahman Steers ◽  
The Impact

Abstract Temperament impacts skeletal muscle mitochondria in Brahman heifers, but this has not been investigated in steers or between cattle breeds. We hypothesized mitochondrial measures would be greater in Angus than Brahman, temperamental than calm steers, and the trapezius (TRAP) than the longissimus thoracis (LT) muscle. Samples from calm (n = 13 per breed), intermediate (n = 12 per breed), and temperamental (n=13 per breed) Angus and Brahman steers (mean±SD 10.0±0.8 mo) were evaluated for mitochondrial enzyme activities via colorimetry. Calm and temperamental LT samples were evaluated for oxidative phosphorylation (P) and electron transfer (E) capacities by high-resolution respirometry. Data were analyzed using linear models with fixed effects of breed, muscle, temperament, and all interactions. Brahman tended to have greater mitochondrial volume density (citrate synthase activity; CS) than Angus (P = 0.08), while intrinsic (relative to CS) mitochondrial function (cytochrome c oxidase activity) was greater in Angus than Brahman (P = 0.001) and greater in TRAP than LT (P = 0.008). Angus exhibited greater integrative (per mg tissue) and intrinsic P with complex I (PCI), P with complexes I+II (PCI+II), maximum noncoupled E, and E with complex II (ECII; P ≤ 0.04) and tended to have greater intrinsic leak (P = 0.1) than Brahman. Contribution of PCI to total E was greater in Angus than Brahman (P = 0.01), while contribution of ECII to total E was greater in Brahman than Angus (P = 0.05). A trend for the interaction of breed and temperament (P = 0.07) indicated calm Angus had the greatest intrinsic ECII (P ≤ 0.03) while intrinsic ECII was similar between temperamental Angus and calm and temperamental Brahman. Integrative PCI+II and ECII, and the contribution of PCI and PCI+II to overall E tended to be greater in temperamental than calm steers (P ≤ 0.09), while intrinsic ECII tended to be greater in calm than temperamental steers (P = 0.07). The impact of these mitochondrial differences on meat quality measures remains to be determined.

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.

Influence of training on skeletal muscle enzymatic adaptations in normal and diabetic rats

1985 ◽  
Vol 249 (4) ◽  
pp. E360-E365 ◽  
Author(s):  
E. G. Noble ◽  
C. D. Ianuzzo
Keyword(s):  
Skeletal Muscle ◽  
Exercise Training ◽  
Citrate Synthase ◽  
Diabetic Rats ◽  
Muscle Fiber Types ◽  
Fiber Types ◽  
Marker Enzymes ◽  
Oxidative Potential ◽  
Hydroxyacyl Coa Dehydrogenase ◽  
Fast Twitch

Muscle homogenates representing slow-twitch oxidative, fast-twitch oxidative-glycolytic, fast-twitch glycolytic, and mixed fiber types were prepared from normal, diabetic, and insulin-treated diabetic rats. Diabetes was induced by injection of 80 mg . kg-1 of streptozotocin. The activities of citrate synthase, succinate dehydrogenase, and 3-hydroxyacyl-CoA dehydrogenase were employed as markers of oxidative potential, whereas phosphorylase, hexokinase, and phosphofructokinase activities were used as an indication of glycolytic capacity. Diabetes was associated with a general decrement in the activity of oxidative marker enzymes for all fiber types except the fast-twitch glycolytic fiber. In contrast, the fast-twitch glycolytic fibers demonstrated the greatest decline in glycolytic enzymatic activity. Insulin-treated animals, either trained or untrained, exhibited enzyme activities similar to their normal counterparts. Exercise training of diabetic rats mimicked the effect of insulin treatment and caused a near normalization of the activity of the marker enzymes. These findings suggest that the enzymatic potential of all skeletal muscle fiber types of diabetic rats may be normalized by exercise training even in the absence of significant amounts of insulin.

Muscle blood flow during exercise in sedentary and trained hypothyroid rats

1995 ◽  
Vol 269 (6) ◽  
pp. H1949-H1954 ◽  
Author(s):  
R. M. McAllister ◽  
M. D. Delp ◽  
K. A. Thayer ◽  
M. H. Laughlin
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Muscle Blood Flow ◽  
Treadmill Running ◽  
Exercise Intolerance ◽  
Vastus Lateralis Muscle ◽  
Blood Flows ◽  
Vastus Intermedius

Hypothyroidism is characterized by exercise intolerance. We hypothesized that active muscle blood flow during in vivo exercise is inadequate in the hypothyroid state. Additionally, we hypothesized that endurance exercise training would restore normal blood flow during acute exercise. To test these hypotheses, rats were made hypothyroid (Hypo) over 3-4 mo with propylthiouracil. A subset of Hypo rats was trained (THypo) on a treadmill at 30 m/min (15% grade) for 60 min/day 5 days/wk over 10-15 wk. Hypothyroidism was evidenced by approximately 80% reductions in plasma triiodothyronine levels in Hypo and THypo and by 40-50% reductions in citrate synthase activities in high oxidative muscles in Hypo compared with euthyroid (Eut) rats. Training efficacy was indicated by increased (25-100%) citrate synthase activities in muscles of THypo vs. Hypo. Regional blood flows were determined by the radiolabeled microsphere method before exercise and at 1-2 min of treadmill running at 15 m/min (0% grade). Preexercise muscle blood flows were generally similar among groups. During exercise, however, flows were lower in Hypo than in Eut for high oxidative muscles such as the red section of vastus lateralis [277 +/- 24 and 153 +/- 13 (SE) ml.min-1.100 g-1 for Eut and Hypo, respectively; P < 0.01] and vastus intermedius (317 +/- 32 and 187 +/- 20 ml.min-1.100 g-1 for Eut and Hypo, respectively; P < 0.01) muscles. Training (THypo) did not normalize these flows (168 +/- 24 and 181 +/- 24 ml.min-1.100 g-1 for red section of vastus lateralis and vastus intermedius muscles, respectively). Blood flows to low oxidative muscle, such as the white section of vastus lateralis muscle, were similar among groups (21 +/- 5, 25 +/- 4, and 34 +/- 7 ml.min-1.100 g-1 for Eut, Hypo, and THypo, respectively; P = NS). These findings indicate that hypothyroidism is associated with reduced blood flow to skeletal muscle during exercise, suggesting that impaired delivery of nutrients to and/or removal of metabolites from skeletal muscle contributes to the poor exercise tolerance characteristic of hypothyroidism.

CB2 antagonism increases citrate synthase activity in slow oxidative skeletal muscle in a diet induced obese model

2013 ◽  
Vol 7 ◽  
pp. e44
Author(s):  
Lannie O’Keefe ◽  
Kayte Jenkin ◽  
Anna Simcocks ◽  
Deanne Hryciw ◽  
Michael Mathai ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Citrate Synthase

scholarly journals Cardiovascular and skeletal muscle health with lifelong exercise

2018 ◽  
Vol 125 (5) ◽  
pp. 1636-1645 ◽  
Author(s):  
Kevin J. Gries ◽  
Ulrika Raue ◽  
Ryan K. Perkins ◽  
Kaleen M. Lavin ◽  
Brittany S. Overstreet ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Oxygen Consumption ◽  
Aerobic Exercise ◽  
Muscle Biopsy ◽  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Metabolic Phenotype ◽  
Vastus Lateralis Muscle ◽  
Metabolic Fitness ◽  
Lifelong Exercise

The purpose of this study was to examine the effects of aerobic lifelong exercise (LLE) on maximum oxygen consumption (V̇o2max) and skeletal muscle metabolic fitness in trained women ( n = 7, 72 ± 2 yr) and men ( n = 21, 74 ± 1 yr) and compare them to old, healthy nonexercisers (OH; women: n = 10, 75 ± 1 yr; men: n = 10, 75 ± 1 yr) and young exercisers (YE; women: n = 10, 25 ± 1 yr; men: n = 10, 25 ± 1 yr). LLE men were further subdivided based on intensity of lifelong exercise and competitive status into performance (LLE-P, n = 14) and fitness (LLE-F, n = 7). On average, LLE exercised 5 day/wk for 7 h/wk over the past 52 ± 1 yr. Each subject performed a maximal cycle test to assess V̇o2maxand had a vastus lateralis muscle biopsy to examine capillarization and metabolic enzymes [citrate synthase, β-hydroxyacyl-CoA dehydrogenase (β-HAD), and glycogen phosphorylase]. V̇o2maxhad a hierarchical pattern (YE > LLE > OH, P < 0.05) for women (44 ± 2 > 26 ± 2 > 18 ± 1 ml·kg−1·min−1) and men (53 ± 3 > 34 ± 1 > 22 ± 1 ml·kg−1·min−1) and was greater ( P < 0.05) in LLE-P (38 ± 1 ml·kg−1·min−1) than LLE-F (27 ± 2 ml·kg−1·min−1). LLE men regardless of intensity and women had similar capillarization and aerobic enzyme activity (citrate synthase and β-HAD) as YE, which were 20%–90% greater ( P < 0.05) than OH. In summary, these data show a substantial V̇o2maxbenefit with LLE that tracked similarly between the sexes, with further enhancement in performance-trained men. For skeletal muscle, 50+ years of aerobic exercise fully preserved capillarization and aerobic enzymes, regardless of intensity. These data suggest that skeletal muscle metabolic fitness may be easier to maintain with lifelong aerobic exercise than more central aspects of the cardiovascular system.NEW & NOTEWORTHY Lifelong exercise (LLE) is a relatively new and evolving area of study with information especially limited in women and individuals with varying exercise intensity habits. These data show a substantial maximal oxygen consumption benefit with LLE that tracked similarly between the sexes. Our findings contribute to the very limited skeletal muscle biopsy data from LLE women (>70 yr), and similar to men, revealed a preserved metabolic phenotype comparable to young exercisers.

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