Human skeletal muscle creatine transporter mRNA and protein expression in healthy, young males and females

α-lipoic acid has been found to enhance glucose uptake into skeletal muscle in animal models. Studies have also found that the co-ingestion of carbohydrate along with creatine increases muscle creatine uptake by a process related to insulin-stimulated glucose disposal. The purpose of this study was to determine the effect of α-lipoic acid on human skeletal muscle creatine uptake by directly measuring intramuscular concentrations of creatine, phosphocreatine, and ad-enosine triphosphate when creatine monohydrate was co-ingested with α-lipoic acid. Muscle biopsies were acquired from the vastus lateralis m. of 16 male subjects (18–32 y) before and after the experimental intervention. After the initial biopsy, subjects ingested 20 g · d−1 of creatine monohydrate, 20 g · d−1 of creatine monohydrate + 100 g · d−1 of sucrose, or 20 g · d−1 of creatine monohydrate + 100 g · d−1 of sucrose + 1000 mg · d−1 of α-lipoic acid for 5 days. Subjects refrained from exercise and consumed the same balanced diet for 7 days. Body weight increased by 2.1% following the nutritional intervention, with no differences between the groups. There was a significant increase in total creatine concentration following creatine supplementation, with the group ingesting α-lipoic acid showing a significantly greater increase (p < .05) in phosphocreatine (87.6 → 106.2 mmol · kg−1 dry mass [dm]) and total creatine (137.8 → 156.8 mmol · kg−1 dm). These findings indicate that co-ingestion of α-lipoic acid with creatine and a small amount of sucrose can enhance muscle total creatine content as compared to the ingestion of creatine and sucrose or creatine alone.

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The effects of aging, physical training, and a single bout of exercise on mitochondrial protein expression in human skeletal muscle

Experimental Gerontology ◽

10.1016/j.exger.2012.03.004 ◽

2012 ◽

Vol 47 (6) ◽

pp. 417-424 ◽

Cited By ~ 59

Author(s):

Zoltan Bori ◽

Zhongfu Zhao ◽

Erika Koltai ◽

Ioannis G. Fatouros ◽

Athanasios Z. Jamurtas ◽

...

Keyword(s):

Skeletal Muscle ◽

Protein Expression ◽

Physical Training ◽

Human Skeletal Muscle ◽

Mitochondrial Protein ◽

Single Bout ◽

Effects Of Aging

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Skeletal muscle fibre types, enzyme activities and physical performance in young males and females

Acta Physiologica Scandinavica ◽

10.1111/j.1748-1716.1978.tb06208.x ◽

1978 ◽

Vol 103 (2) ◽

pp. 210-218 ◽

Cited By ~ 123

Author(s):

P. V. Komi ◽

J. Karlsson

Keyword(s):

Skeletal Muscle ◽

Muscle Fibre ◽

Physical Performance ◽

Enzyme Activities ◽

Skeletal Muscle Fibre ◽

Fibre Types ◽

Muscle Fibre Types ◽

Young Males ◽

Males And Females

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Antioxidants Facilitate High–intensity Exercise IL–15 Expression in Skeletal Muscle

International Journal of Sports Medicine ◽

10.1055/a-0781-2527 ◽

2018 ◽

Vol 40 (01) ◽

pp. 16-22 ◽

Cited By ~ 2

Author(s):

Alberto Pérez-López ◽

Marcos Martin-Rincon ◽

Alfredo Santana ◽

Ismael Perez-Suarez ◽

Cecilia Dorado ◽

...

Keyword(s):

Skeletal Muscle ◽

Protein Expression ◽

High Intensity ◽

Human Skeletal Muscle ◽

Vastus Lateralis ◽

Acute Hypoxia ◽

High Intensity Exercise ◽

Oxygen Deficit ◽

Post Exercise ◽

Sprint Exercise

AbstractInterleukin (IL)-15 stimulates mitochondrial biogenesis, fat oxidation, glucose uptake and myogenesis in skeletal muscle. However, the mechanisms by which exercise triggers IL-15 expression remain to be elucidated in humans. This study aimed at determining whether high-intensity exercise and exercise-induced RONS stimulate IL-15/IL-15Rα expression and its signaling pathway (STAT3) in human skeletal muscle. Nine volunteers performed a 30-s Wingate test in normoxia and hypoxia (PIO2=75 mmHg), 2 h after placebo or antioxidant administration (α-lipoic acid, vitamin C and E) in a randomized double-blind design. Blood samples and muscle biopsies (vastus lateralis) were obtained before, immediately after, and 30 and 120 min post-exercise. Sprint exercise upregulated skeletal muscle IL-15 protein expression (ANOVA, P=0.05), an effect accentuated by antioxidant administration in hypoxia (ANOVA, P=0.022). In antioxidant conditions, the increased IL-15 expression at 120 min post-exercise (33%; P=0.017) was associated with the oxygen deficit caused by the sprint (r=–0.54; P=0.020); while, IL-15 and Tyr705-STAT3 AUCs were also related (r=0.50; P=0.036). Antioxidant administration promotes IL-15 protein expression in human skeletal muscle after sprint exercise, particularly in severe acute hypoxia. Therefore, during intense muscle contraction, a reduced PO2 and glycolytic rate, and possibly, an attenuated RONS generation may facilitate IL-15 production, accompanied by STAT3 activation, in a process that does not require AMPK phosphorylation.

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Progressive increase in human skeletal muscle AMPKα2 activity and ACC phosphorylation during exercise

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00101.2001 ◽

2002 ◽

Vol 282 (3) ◽

pp. E688-E694 ◽

Cited By ~ 95

Author(s):

T. J. Stephens ◽

Z.-P. Chen ◽

B. J. Canny ◽

B. J. Michell ◽

B. E. Kemp ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Glycogen ◽

Human Skeletal Muscle ◽

Glycogen Content ◽

Vastus Lateralis ◽

Moderate Intensity ◽

Moderate Intensity Exercise ◽

Western Blots ◽

Muscle Glycogen Content ◽

Muscle Creatine

The effect of prolonged moderate-intensity exercise on human skeletal muscle AMP-activated protein kinase (AMPK)α1 and -α2 activity and acetyl-CoA carboxylase (ACCβ) and neuronal nitric oxide synthase (nNOSμ) phosphorylation was investigated. Seven active healthy individuals cycled for 30 min at a workload requiring 62.8 ± 1.3% of peak O2consumption (V˙o 2 peak) with muscle biopsies obtained from the vastus lateralis at rest and at 5 and 30 min of exercise. AMPKα1 activity was not altered by exercise; however, AMPKα2 activity was significantly ( P < 0.05) elevated after 5 min (∼2-fold), and further elevated ( P < 0.05) after 30 min (∼3-fold) of exercise. ACCβ phosphorylation was increased ( P < 0.05) after 5 min (∼18-fold compared with rest) and increased ( P< 0.05) further after 30 min of exercise (∼36-fold compared with rest). Increases in AMPKα2 activity were significantly correlated with both increases in ACCβ phosphorylation and reductions in muscle glycogen content. Fat oxidation tended ( P = 0.058) to increase progressively during exercise. Muscle creatine phosphate was lower ( P < 0.05), and muscle creatine, calculated free AMP, and free AMP-to-ATP ratio were higher ( P < 0.05) at both 5 and 30 min of exercise compared with those at rest. At 30 min of exercise, the values of these metabolites were not significantly different from those at 5 min of exercise. Phosphorylation of nNOSμ was variable, and despite the mean doubling with exercise, statistically significance was not achieved ( P = 0.304). Western blots indicated that AMPKα2 was associated with both nNOSμ and ACCβ consistent with them both being substrates of AMPKα2 in vivo. In conclusion, AMPKα2 activity and ACCβ phosphorylation increase progressively during moderate exercise at ∼60% of V˙o 2 peak in humans, with these responses more closely coupled to muscle glycogen content than muscle AMP/ATP ratio.

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A 7‐day high‐fat, high‐calorie diet induces fibre‐specific increases in intramuscular triglyceride and perilipin protein expression in human skeletal muscle

The Journal of Physiology ◽

10.1113/jp279129 ◽

2020 ◽

Vol 598 (6) ◽

pp. 1151-1167 ◽

Cited By ~ 2

Author(s):

K. L. Whytock ◽

S. A. Parry ◽

M. C. Turner ◽

R. M. Woods ◽

L. J. James ◽

...

Keyword(s):

Skeletal Muscle ◽

Protein Expression ◽

Human Skeletal Muscle ◽

High Fat ◽

Calorie Diet ◽

Intramuscular Triglyceride ◽

High Calorie Diet ◽

High Calorie

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Immobilization Decreases FOXO3a Phosphorylation and Increases Autophagy-Related Gene and Protein Expression in Human Skeletal Muscle

Frontiers in Physiology ◽

10.3389/fphys.2019.00736 ◽

2019 ◽

Vol 10 ◽

Cited By ~ 6

Author(s):

Andreas Buch Møller ◽

Mikkel Holm Vendelbo ◽

Peter Schjerling ◽

Christian Couppé ◽

Niels Møller ◽

...

Keyword(s):

Skeletal Muscle ◽

Protein Expression ◽

Human Skeletal Muscle ◽

Related Gene ◽

Gene And Protein Expression

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Insulin signaling displayed a differential tissue-specific response to low-dose dihydrotestosterone in female mice

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00195.2017 ◽

2018 ◽

Vol 314 (4) ◽

pp. E353-E365 ◽

Cited By ~ 4

Author(s):

Stanley Andrisse ◽

Katelyn Billings ◽

Ping Xue ◽

Sheng Wu

Keyword(s):

Insulin Resistance ◽

Skeletal Muscle ◽

Energy Storage ◽

Protein Expression ◽

Insulin Signaling ◽

Low Dose ◽

Specific Response ◽

Pituitary Cells ◽

Reproductive Tissues ◽

Mrna And Protein Expression

Hyperandrogenemia and hyperinsulinemia are believed to play prominent roles in polycystic ovarian syndrome (PCOS). We explored the effects of low-dose dihydrotestosterone (DHT), a model of PCOS, on insulin signaling in metabolic and reproductive tissues in a female mouse model. Insulin resistance in the energy storage tissues is associated with type 2 diabetes. Insulin signaling in the ovaries and pituitary either directly or indirectly stimulates androgen production. Energy storage and reproductive tissues were isolated and molecular assays were performed. Livers and white adipose tissue (WAT) from DHT mice displayed lower mRNA and protein expression of insulin signaling intermediates. However, ovaries and pituitaries of DHT mice exhibited higher expression levels of insulin signaling genes/proteins. Insulin-stimulated p-AKT levels were blunted in the livers and WAT of the DHT mice but increased or remained the same in the ovaries and pituitaries compared with controls. Glucose uptake decreased in liver and WAT but was unchanged in pituitary and ovary of DHT mice. Plasma membrane GLUTs were decreased in liver and WAT but increased in ovary and pituitary of DHT mice. Skeletal muscle insulin-signaling genes were not lowered in DHT mice compared with control. DHT mice did not display skeletal muscle insulin resistance. Insulin-stimulated glucose transport increased in skeletal muscles of DHT mice compared with controls. DHT mice were hyperinsulinemic. However, the differential mRNA and protein expression pattern was independent of hyperinsulinemia in cultured hepatocytes and pituitary cells. These findings demonstrate a differential effect of DHT on the insulin-signaling pathway in energy storage vs. reproductive tissues independent of hyperinsulinemia.

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