Effects of Endurance Exercise and Ginsenoside Rb1on AMP-Activated Protein Kinase, Phosphatidylinositol 3-Kinase Expression and Glucose Uptake in the Skeletal Muscle of Rats

2013 ◽  
Vol 42 (8) ◽  
pp. 1197-1203
Author(s):  
Hyun-Lyung Jung ◽  
Young Ho Shin ◽  
Ho-Youl Kang
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
Glucose Uptake ◽  
Endurance Exercise ◽  
Phosphatidylinositol 3 Kinase ◽  
Amp Activated Protein Kinase ◽  
Kinase Expression ◽  
Phosphatidylinositol 3

scholarly journals Corticotropin-Releasing Hormone Directly Stimulates Thermogenesis in Skeletal Muscle Possibly through Substrate Cycling between de Novo Lipogenesis and Lipid Oxidation

Endocrinology ◽  
2006 ◽  
Vol 147 (1) ◽  
pp. 31-38 ◽  
Author(s):  
G. Solinas ◽  
S. Summermatter ◽  
D. Mainieri ◽  
M. Gubler ◽  
J. P. Montani ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
Lipid Oxidation ◽  
De Novo ◽  
De Novo Lipogenesis ◽  
Phosphatidylinositol 3 Kinase ◽  
Intact Mouse ◽  
Amp Activated Protein Kinase ◽  
Protein Kinase Signaling ◽  
Phosphatidylinositol 3

The mechanisms by which CRH and related peptides (i.e. the CRH/urocortin system) exert their control over thermogenesis and weight regulation have until now focused only upon their effects on brain centers controlling sympathetic outflow. Using a method that involves repeated oxygen uptake determinations in intact mouse skeletal muscle, we report here that CRH can act directly on skeletal muscle to stimulate thermogenesis, an effect that is more pronounced in oxidative than in glycolytic muscles and that can be inhibited by a selective CRH-R2 antagonist or blunted by a nonselective CRH receptor antagonist. This thermogenic effect of CRH can also be blocked by interference along pathways of de novo lipogenesis and lipid oxidation, as well as by inhibitors of phosphatidylinositol 3-kinase or AMP-activated protein kinase. Taken together, these studies demonstrate that CRH can directly stimulate thermogenesis in skeletal muscle, and in addition raise the possibility that this thermogenic effect, which requires both phosphatidylinositol 3-kinase and AMP-activated protein kinase signaling, might occur via substrate cycling between de novo lipogenesis and lipid oxidation. The effect of CRH in directly stimulating thermogenesis in skeletal muscle underscores a potentially important peripheral role for the CRH/urocortin system in the control of thermogenesis in this tissue, in its protection against excessive intramyocellular lipid storage, and hence against skeletal muscle lipotoxicity and insulin resistance.

AMP-activated protein kinase activity and glucose uptake in rat skeletal muscle

2001 ◽  
Vol 280 (5) ◽  
pp. E677-E684 ◽  
Author(s):  
Nicolas Musi ◽  
Tatsuya Hayashi ◽  
Nobuharu Fujii ◽  
Michael F. Hirshman ◽  
Lee A. Witters ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
Glucose Uptake ◽  
Muscle Contractions ◽  
Treadmill Running ◽  
Dependent Manner ◽  
Rat Skeletal Muscle ◽  
Amp Activated Protein Kinase ◽  
Dose Dependent

The AMP-activated protein kinase (AMPK) has been hypothesized to mediate contraction and 5-aminoimidazole-4-carboxamide 1-β-d-ribonucleoside (AICAR)-induced increases in glucose uptake in skeletal muscle. The purpose of the current study was to determine whether treadmill exercise and isolated muscle contractions in rat skeletal muscle increase the activity of the AMPKα1 and AMPKα2 catalytic subunits in a dose-dependent manner and to evaluate the effects of the putative AMPK inhibitors adenine 9-β-d-arabinofuranoside (ara-A), 8-bromo-AMP, and iodotubercidin on AMPK activity and 3- O-methyl-d-glucose (3-MG) uptake. There were dose-dependent increases in AMPKα2 activity and 3-MG uptake in rat epitrochlearis muscles with treadmill running exercise but no effect of exercise on AMPKα1 activity. Tetanic contractions of isolated epitrochlearis muscles in vitro significantly increased the activity of both AMPK isoforms in a dose-dependent manner and at a similar rate compared with increases in 3-MG uptake. In isolated muscles, the putative AMPK inhibitors ara-A, 8-bromo-AMP, and iodotubercidin fully inhibited AICAR-stimulated AMPKα2 activity and 3-MG uptake but had little effect on AMPKα1 activity. In contrast, these compounds had absent or minimal effects on contraction-stimulated AMPKα1 and -α2 activity and 3-MG uptake. Although the AMPKα1 and -α2 isoforms are activated during tetanic muscle contractions in vitro, in fast-glycolytic fibers, the activation of AMPKα2-containing complexes may be more important in regulating exercise-mediated skeletal muscle metabolism in vivo. Development of new compounds will be required to study contraction regulation of AMPK by pharmacological inhibition.

scholarly journals Effect of Quercetin Treatment on Mitochondrial Biogenesis and Exercise-Induced AMP-Activated Protein Kinase Activation in Rat Skeletal Muscle

Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 729 ◽  
Author(s):  
Keiichi Koshinaka ◽  
Asuka Honda ◽  
Hiroyuki Masuda ◽  
Akiko Sato
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
Endurance Exercise ◽  
Mitochondrial Biogenesis ◽  
Exercise Performance ◽  
Term Therapy ◽  
High Dose ◽  
Rat Skeletal Muscle ◽  
Amp Activated Protein Kinase ◽  
Quercetin Treatment

The purpose of this study was to evaluate the effect of chronic quercetin treatment on mitochondrial biogenesis, endurance exercise performance and activation levels of AMP-activated protein kinase (AMPK) in rat skeletal muscle. Rats were assigned to a control or quercetin group and were fed for 7 days. Rats treated with quercetin showed no changes in the protein levels of citrate synthase or cytochrome C oxidase IV or those of sirtuin 1, peroxisome proliferator-activated receptor gamma coactivator-1α or phosphorylated AMPK. After endurance swimming exercise, quercetin-treated rats demonstrated no differences in blood and muscle lactate levels or glycogen utilization speed compared to control rats. These results indicate that quercetin treatment does not stimulate mitochondrial biogenesis in skeletal muscle and does not influence metabolism in a way that might enhance endurance exercise capacity. On the other hand, the AMPK phosphorylation level immediately after exercise was significantly lower in quercetin-treated muscles, suggesting that quercetin treatment might provide a disadvantage to muscle adaptation when administered with exercise training. The molecular results of this study indicate that quercetin treatment may not be advantageous for improving endurance exercise performance, at least after high-dose and short-term therapy.

AICA riboside increases AMP-activated protein kinase, fatty acid oxidation, and glucose uptake in rat muscle

1997 ◽  
Vol 273 (6) ◽  
pp. E1107-E1112 ◽  
Author(s):  
G. F. Merrill ◽  
E. J. Kurth ◽  
D. G. Hardie ◽  
W. W. Winder
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acid ◽  
Protein Kinase ◽  
Glucose Uptake ◽  
Fatty Acid Oxidation ◽  
Fold Increase ◽  
Acid Oxidation ◽  
Acetyl Coa Carboxylase ◽  
Malonyl Coa ◽  
Amp Activated Protein Kinase

5-Aminoimidazole-4-carboxamide ribonucleoside (AICAR) has previously been reported to be taken up into cells and phosphorylated to form ZMP, an analog of 5′-AMP. This study was designed to determine whether AICAR can activate AMP-activated protein kinase (AMPK) in skeletal muscle with consequent phosphorylation of acetyl-CoA carboxylase (ACC), decrease in malonyl-CoA, and increase in fatty acid oxidation. Rat hindlimbs were perfused with Krebs-Henseleit bicarbonate containing 4% bovine serum albumin, washed bovine red blood cells, 200 μU/ml insulin, and 10 mM glucose with or without AICAR (0.5–2.0 mM). Perfusion with medium containing AICAR was found to activate AMPK in skeletal muscle, inactivate ACC, and decrease malonyl-CoA. Hindlimbs perfused with 2 mM AICAR for 45 min exhibited a 2.8-fold increase in fatty acid oxidation and a significant increase in glucose uptake. No difference was observed in oxygen uptake in AICAR vs. control hindlimb. These results provide evidence that decreases in muscle content of malonyl-CoA can increase the rate of fatty acid oxidation.

Muscle-specific overexpression of wild type and R225Q mutant AMP-activated protein kinase γ3-subunit differentially regulates glycogen accumulation

2006 ◽  
Vol 291 (3) ◽  
pp. E557-E565 ◽  
Author(s):  
Haiyan Yu ◽  
Michael F. Hirshman ◽  
Nobuharu Fujii ◽  
Jason M. Pomerleau ◽  
Lauren E. Peter ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
Glucose Uptake ◽  
Glycogen Content ◽  
Specific Activity ◽  
Glycogen Synthase ◽  
Underlying Mechanism ◽  
Wild Type ◽  
Glycogen Accumulation ◽  
Amp Activated Protein Kinase

AMP-activated protein kinase (AMPK) is a heterotrimeric complex that works as an energy sensor to integrate nutritional and hormonal signals. The naturally occurring R225Q mutation in the γ3-subunit in pigs is associated with abnormally high glycogen content in skeletal muscle. Becauses skeletal muscle accounts for most of the body's glucose uptake, and γ3 is specifically expressed in skeletal muscle, it is important to understand the underlying mechanism of this mutation in regulating glucose and glycogen metabolism. Using skeletal muscle-specific transgenic mice overexpressing wild type γ3 (WTγ3) and R225Q mutant γ3 (MUTγ3), we show that both WTγ3 and MUTγ3 mice have 1.5- to 2-fold increases in muscle glycogen content. In WTγ3 mice, increased glycogen content was associated with elevated total glycogen synthase activity and reduced glycogen phosphorylase activity, whereas alterations in activities of these enzymes could not explain elevated glycogen in MUTγ3 mice. Basal, 5-aminoimidazole- AICAR- and phenformin-stimulated AMPKα2 isoform-specific activities were decreased only in MUTγ3 mice. Basal rates of 2-DG glucose uptake were decreased in both WTγ3 and MUTγ3 mice. However, AICAR- and phenformin-stimulated 2-DG glucose uptake were blunted only in MUTγ3 mice. In conclusion, expression of either wild type or mutant γ3-subunit of AMPK results in increased glycogen concentrations in muscle, but the mechanisms underlying this alteration appear to be different. Furthermore, mutation of the γ3-subunit is associated with decreases in AMPKα2 isoform-specific activity and impairment in AICAR- and phenformin-stimulated skeletal muscle glucose uptake.

scholarly journals Oxidative stress stimulates skeletal muscle glucose uptake through a phosphatidylinositol 3-kinase-dependent pathway

2008 ◽  
Vol 294 (5) ◽  
pp. E889-E897 ◽  
Author(s):  
Yasuki Higaki ◽  
Toshio Mikami ◽  
Nobuharu Fujii ◽  
Michael F. Hirshman ◽  
Katsuhiro Koyama ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Skeletal Muscle ◽  
Glucose Uptake ◽  
Intracellular Signaling ◽  
Phosphatidylinositol 3 Kinase ◽  
Maximal Increase ◽  
Skeletal Muscle Glucose Uptake ◽  
Dose Dependent Increase ◽  
Dose Dependent ◽  
Phosphatidylinositol 3

We determined the acute effects of oxidative stress on glucose uptake and intracellular signaling in skeletal muscle by incubating muscles with reactive oxygen species (ROS). Xanthine oxidase (XO) is a superoxide-generating enzyme that increases ROS. Exposure of isolated rat extensor digitorum longus (EDL) muscles to Hx/XO (Hx/XO) for 20 min resulted in a dose-dependent increase in glucose uptake. To determine whether the mechanism leading to Hx/XO-stimulated glucose uptake is associated with the production of H2O2, EDL muscles from rats were preincubated with the H2O2 scavenger catalase or the superoxide scavenger superoxide dismutase (SOD) prior to incubation with Hx/XO. Catalase treatment, but not SOD, completely inhibited the increase in Hx/XO-stimulated 2-deoxyglucose (2-DG) uptake, suggesting that H2O2 is an intermediary leading to Hx/XO-stimulated glucose uptake with incubation. Direct H2O2 also resulted in a dose-dependent increase in 2-DG uptake in isolated EDL muscles, and the maximal increase was threefold over basal levels at a concentration of 600 μmol/l H2O2. H2O2-stimulated 2-DG uptake was completely inhibited by the phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin, but not the nitric oxide inhibitor N G-monomethyl-l-arginine. H2O2 stimulated the phosphorylation of Akt Ser473 (7-fold) and Thr308 (2-fold) in isolated EDL muscles. H2O2 at 600 μmol/l had no effect on ATP concentrations and did not increase the activities of either the α1 or α2 catalytic isoforms of AMP-activated protein kinase. These results demonstrate that acute exposure of muscle to ROS is a potent stimulator of skeletal muscle glucose uptake and that this occurs through a PI3K-dependent mechanism.

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