The in vitro effect of corticosterone on insulin binding and glucose metabolism in mouse skeletal muscles

1985 ◽  
Vol 63 (9) ◽  
pp. 1133-1138 ◽  
Author(s):  
M. H. Tan ◽  
A. Bonen
Keyword(s):  
Skeletal Muscle ◽  
Skeletal Muscles ◽  
Extensor Digitorum Longus ◽  
Insulin Binding ◽  
In Vivo Model ◽  
In Vitro System ◽  
Vitro Effect ◽  
Contralateral Muscle

We studied the in vitro effect of corticosterone on insulin binding, uptake of 2-deoxy-D-glucose, glycolysis, and glycogenesis in the soleus and extensor digitorum longus (EDL) of Swiss–Webster mice. In each experiment, one muscle (soleus/EDL) was incubated with corticosterone (0.1, 1, 50, and 100 μg/mL) and the respective contralateral muscle was incubated without corticosterone, but at the same insulin and pH levels. Corticosterone did not affect insulin binding in both muscles. However, corticosterone decreased the uptake of 2-deoxy-D-glucose and the rate of glycolysis and glycogenesis in both muscles when the dose was pharmacologic (50 and 100 μg/mL), but not when it was physiologic (0.1 and 1 μg/mL). For glycolysis and glycogenesis, the suppression was greater in the EDL when compared with the soleus. This suppression was seen in both basal and insulin-stimulated conditions. In this in vitro system, where the experimental muscle is not exposed to prior hyperinsulinemia as in the in vivo model, corticosterone, at pharmacologic doses, affects postreceptor events without altering the insulin binding in the skeletal muscle.

scholarly journals Anti-Diabetic Effects and Anti-Inflammatory Effects of Laminaria japonica and Hizikia fusiforme in Skeletal Muscle: In Vitro and In Vivo Model

Nutrients ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 491 ◽  
Author(s):  
Sae-ym Kang ◽  
Eunyoung Kim ◽  
Inhae Kang ◽  
Myoungsook Lee ◽  
Yunkyoung Lee
Keyword(s):  
Skeletal Muscle ◽  
Laminaria Japonica ◽  
In Vivo Model ◽  
Hizikia Fusiforme ◽  
Anti Inflammatory

Expression of steroidogenic enzymes and synthesis of sex steroid hormones from DHEA in skeletal muscle of rats

2007 ◽  
Vol 292 (2) ◽  
pp. E577-E584 ◽  
Author(s):  
Katsuji Aizawa ◽  
Motoyuki Iemitsu ◽  
Seiji Maeda ◽  
Subrina Jesmin ◽  
Takeshi Otsuki ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Steroid Hormones ◽  
Skeletal Muscles ◽  
Muscle Cells ◽  
Sex Steroid Hormones ◽  
Sex Steroid ◽  
Dependent Manner ◽  
Steroidogenic Enzymes

The functional importance of sex steroid hormones (testosterone and estrogens), derived from extragonadal tissues, has recently gained significant appreciation. Circulating dehydroepiandrosterone (DHEA) is peripherally taken up and converted to testosterone by 3β-hydroxysteroid dehydrogenase (HSD) and 17β-HSD, and testosterone in turn is irreversibly converted to estrogens by aromatase cytochrome P-450 (P450arom). Although sex steroid hormones have been implicated in skeletal muscle regulation and adaptation, it is unclear whether skeletal muscles have a local steroidogenic enzymatic machinery capable of metabolizing circulating DHEA. Thus, here, we investigate whether the three key steroidogenic enzymes (3β-HSD, 17β-HSD, and P450arom) are present in the skeletal muscle and are capable of generating sex steroid hormones. Consistent with our hypothesis, the present study demonstrates mRNA and protein expression of these enzymes in the skeletal muscle cells of rats both in vivo and in culture (in vitro). Importantly, we also show an intracellular formation of testosterone and estradiol from DHEA or testosterone in cultured muscle cells in a dose-dependent manner. These findings are novel and important in that they provide the first evidence showing that skeletal muscles are capable of locally synthesizing sex steroid hormones from circulating DHEA or testosterone.

scholarly journals In Vivo Activation of STAT3 Signaling in Satellite Cells and Myofibers in Regenerating Rat Skeletal Muscles

2002 ◽  
Vol 50 (12) ◽  
pp. 1579-1589 ◽  
Author(s):  
Katsuya Kami ◽  
Emiko Senba
Keyword(s):  
Skeletal Muscle ◽  
Satellite Cells ◽  
Muscle Regeneration ◽  
Intracellular Signaling ◽  
Skeletal Muscles ◽  
Early Stage ◽  
Skeletal Muscle Regeneration ◽  
Stat3 Signaling

Although growth factors and cytokines play critical roles in skeletal muscle regeneration, intracellular signaling molecules that are activated by these factors in regenerating muscles have been not elucidated. Several lines of evidence suggest that leukemia inhibitory factor (LIF) is an important cytokine for the proliferation and survival of myoblasts in vitro and acceleration of skeletal muscle regeneration. To elucidate the role of LIF signaling in regenerative responses of skeletal muscles, we examined the spatial and temporal activation patterns of an LIF-associated signaling molecule, the signal transducer and activator transcription 3 (STAT3) proteins in regenerating rat skeletal muscles induced by crush injury. At the early stage of regeneration, activated STAT3 proteins were first detected in the nuclei of activated satellite cells and then continued to be activated in proliferating myoblasts expressing both PCNA and MyoD proteins. When muscle regeneration progressed, STAT3 signaling was no longer activated in differentiated myoblasts and myotubes. In addition, activation of STAT3 was also detected in myonuclei within intact sarcolemmas of surviving myofibers that did not show signs of necrosis. These findings suggest that activation of STAT3 signaling is an important molecular event that induces the successful regeneration of injured skeletal muscles.

Glutamine Metabolism in Skeletal Muscle of Glucocorticoid-Treated Rats

1990 ◽  
Vol 79 (2) ◽  
pp. 139-147 ◽  
Author(s):  
M. Salleh M. Ardawi ◽  
Yasir S. Jamal
Keyword(s):  
Skeletal Muscle ◽  
Exchange Rates ◽  
Skeletal Muscles ◽  
Plasma Concentrations ◽  
Maximal Activity ◽  
Glutamine Metabolism ◽  
Dexamethasone Treatment ◽  
Concentration Difference

1. The effect of dexamethasone (30 μg day−-1 100 g−-1 body weight) on the regulation of glutamine metabolism was studied in skeletal muscles of rats after 9 days of treatment. 2. Dexamethasone resulted in negative nitrogen balance, and produced increases in the plasma concentrations of alanine (23.4%) and insulin (158%) but a decrease in the plasma concentration of glutamine (28.7%). 3. Dexamethasone treatment increased the rate of glutamine production in muscle, skin and adipose tissue preparations, with muscle production accounting for over 90% of total glutamine produced by the hindlimb. 4. Blood flow and arteriovenous concentration difference measurements across the hindlimb showed an increase in the net exchange rates of glutamine (25.3%) and alanine (90.5%) in dexamethasone-treated rats compared with corresponding controls. 5. Dexamethasone treatment produced significant decreases in the concentrations of skeletal muscle glutamine (51.8%) and 2-oxoglutarate (50.8%). The concentrations of alanine (16.2%), pyruvate (45.9%), ammonia (43.3%) and inosine 5′-phosphate (141.8%) were increased. 6. The maximal activity of glutamine synthetase was increased (21–34%), but there was no change in that of glutaminase, in muscles of dexamethasone-treated rats. 7. It is concluded that glucocorticoid administration enhances the rates of release of both glutamine and alanine from skeletal muscle of rats (both in vitro and in vivo). This may be due to changes in efflux and/or increased intracellular formation of glutamine and alanine.

Factors Controlling Movement of Skeletal Muscles

Leonardo ◽  
2015 ◽  
Vol 48 (3) ◽  
pp. 270-271
Author(s):  
Miranda D. Grounds
Keyword(s):  
Skeletal Muscle ◽  
Extracellular Matrix ◽  
Cell Membrane ◽  
Skeletal Muscles ◽  
Muscle Cells ◽  
The Body ◽  
Skeletal Muscle Cells ◽  
3 Dimensional

The contraction of specialized skeletal muscle cells results in classic movements of bones and other parts of the body that are vital for life. There is exquisite control over the movement of diverse types of muscles. This paper indicates the way in which skeletal muscles (myofibres) are formed; then factors that contribute to generating the movement are outlined: these include the nerve, sarcomeres, cytoskeleton, cell membrane and the extracellular matrix. The factors controlling the movement of mature myofibres in 3-dimensional tissues in vivo are vastly more complex than for tissue cultured immature muscle cells in an artificial in vitro environment.

Potassium depletion increases potassium clearance capacity in skeletal muscles in vivo during acute repletion

2002 ◽  
Vol 283 (4) ◽  
pp. C1163-C1170 ◽  
Author(s):  
Henning Bundgaard ◽  
Keld Kjeldsen
Keyword(s):  
Skeletal Muscle ◽  
Skeletal Muscles ◽  
Ouabain Binding ◽  
K Uptake ◽  
Rate Of Increase ◽  
Increased Risk ◽  
Gastrocnemius Muscles ◽  
K Depletion

Muscular K uptake depends on skeletal muscle Na-K-ATPase concentration and activity. Reduced K uptake is observed in vitro in K-depleted rats. We evaluated skeletal muscle K clearance capacity in vivo in rats K depleted for 14 days. [3H]ouabain binding, α1 and α2 Na-K-ATPase isoform abundance, and K, Na, and Mg content were measured in skeletal muscles. Skeletal muscle K, Na, and Mg and plasma K were measured in relation to intravenous KCl infusion that continued until animals died, i.e., maximum KCl dose was administered. In soleus, extensor digitorum longus (EDL), and gastrocnemius muscles K depletion significantly reduced K content by 18%, 15%, and 19%, [3H]ouabain binding by 36%, 41%, and 68%, and α2 isoform abundance by 34%, 44%, and 70%, respectively. No significant change was observed in α1 isoform abundance. In EDL and gastrocnemius muscles K depletion significantly increased Na (48% and 59%) and Mg (10% and 17%) content, but only tendencies to increase were observed in soleus muscle. K-depleted rats tolerated up to a fourfold higher KCl dose. This was associated with a reduced rate of increase in plasma K and increases in soleus, EDL, and gastrocnemius muscle K of 56%, 42%, and 41%, respectively, but only tendencies to increase in controls. However, whereas K uptake was highest in K-depleted animals, the K uptake rate was highest in controls. In vivo K depletion is associated with markedly increased K tolerance and K clearance despite significantly reduced skeletal muscle Na-K-ATPase concentration. The concern of an increased risk for K intoxication during K repletion seems unwarranted.

scholarly journals Glucose-transporter (GLUT4) protein content in oxidative and glycolytic skeletal muscles from calf and goat

1995 ◽  
Vol 305 (2) ◽  
pp. 465-470 ◽  
Author(s):  
J F Hocquette ◽  
F Bornes ◽  
M Balage ◽  
P Ferre ◽  
J Grizard ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Glucose Uptake ◽  
Glucose Transport ◽  
Skeletal Muscles ◽  
Glucose Transporter ◽  
Transporter Protein ◽  
Rat Muscle ◽  
Glucose Transporter Glut4

It is well accepted that skeletal muscle is a major glucose-utilizing tissue and that insulin is able to stimulate in vivo glucose utilization in ruminants as in monogastrics. In order to determine precisely how glucose uptake is controlled in various ruminant muscles, particularly by insulin, this study was designed to investigate in vitro glucose transport and insulin-regulatable glucose-transporter protein (GLUT4) in muscle from calf and goat. Our data demonstrate that glucose transport is the rate-limiting step for glucose uptake in bovine fibre strips, as in rat muscle. Insulin increases the rate of in vitro glucose transport in bovine muscle, but to a lower extent than in rat muscle. A GLUT4-like protein was detected by immunoblot assay in all insulin-responsive tissues from calf and goat (heart, skeletal muscle, adipose tissue) but not in liver, brain, erythrocytes and intestine. Unlike the rat, bovine and goat GLUT4 content is higher in glycolytic and oxido-glycolytic muscles than in oxidative muscles. In conclusion, using both a functional test (insulin stimulation of glucose transport) and an immunological approach, this study demonstrates that ruminant muscles express GLUT4 protein. Our data also suggest that, in ruminants, glucose is the main energy-yielding substrate for glycolytic but not for oxidative muscles, and that insulin responsiveness may be lower in oxidative than in other skeletal muscles.

scholarly journals In vivo and in vitro effect of p-chlorophenoxyisobutyrate on insulin binding and glucose transport in isolated rat adipocytes.

1985 ◽  
Vol 32 (6) ◽  
pp. 829-836
Author(s):  
NOBUAKI WATANABE ◽  
MASASHI KOBAYASHI ◽  
HIROSHI MAEGAWA ◽  
OSAMU ISHIBASHI ◽  
YASUMITSU TAKATA ◽  
...  
Keyword(s):  
Glucose Transport ◽  
Insulin Binding ◽  
Rat Adipocytes ◽  
Vitro Effect ◽  
Isolated Rat

scholarly journals Neutral sphingomyelinase 2 is required for cytokine-induced skeletal muscle calpain activation

2015 ◽  
Vol 309 (6) ◽  
pp. L614-L624 ◽  
Author(s):  
Gerald S. Supinski ◽  
Alexander P. Alimov ◽  
Lin Wang ◽  
Xiao-Hong Song ◽  
Leigh A. Callahan
Keyword(s):  
Skeletal Muscle ◽  
Cecal Ligation ◽  
C2c12 Cells ◽  
In Vivo Model ◽  
Calpain Activity ◽  
Calpain Activation ◽  
Neutral Sphingomyelinase ◽  
Cecal Ligation Puncture

Calpain contributes to infection-induced diaphragm dysfunction but the upstream mechanism(s) responsible for calpain activation are poorly understood. It is known, however, that cytokines activate neutral sphingomyelinase (nSMase) and nSMase has downstream effects with the potential to increase calpain activity. We tested the hypothesis that infection-induced skeletal muscle calpain activation is a consequence of nSMase activation. We administered cytomix (20 ng/ml TNF-α, 50 U/ml IL-1β, 100 U/ml IFN-γ, 10 μg/ml LPS) to C2C12 muscle cells to simulate the effects of infection in vitro and studied mice undergoing cecal ligation puncture (CLP) as an in vivo model of infection. In cell studies, we assessed sphingomyelinase activity, subcellular calcium levels, and calpain activity and determined the effects of inhibiting sphingomyelinase using chemical (GW4869) and genetic (siRNA to nSMase2 and nSMase3) techniques. We assessed diaphragm force and calpain activity and utilized GW4869 to inhibit sphingomyelinase in mice. Cytomix increased cytosolic and mitochondrial calcium levels in C2C12 cells ( P < 0.001); addition of GW4869 blocked these increases ( P < 0.001). Cytomix also activated calpain, increasing calpain activity ( P < 0.02), and the calpain-mediated cleavage of procaspase 12 ( P < 0.001). Procaspase 12 cleavage was attenuated by either GW4869 ( P < 0.001), BAPTA-AM ( P < 0.001), or siRNA to nSMase2 ( P < 0.001) but was unaffected by siRNA to nSMase3. GW4869 prevented CLP-induced diaphragm calpain activation and diaphragm weakness in mice. These data suggest that nSMase2 activation is required for the development of infection-induced diaphragm calpain activation and muscle weakness. As a consequence, therapies that inhibit nSMase2 in patients may prevent infection-induced skeletal muscle dysfunction.

Characterization of contraction-inducible CXC chemokines and their roles in C2C12 myocytes

2009 ◽  
Vol 297 (4) ◽  
pp. E866-E878 ◽  
Author(s):  
Taku Nedachi ◽  
Hiroyasu Hatakeyama ◽  
Tatsuyoshi Kono ◽  
Masaaki Sato ◽  
Makoto Kanzaki
Keyword(s):  
Skeletal Muscle ◽  
Skeletal Muscles ◽  
Contractile Activity ◽  
Electric Pulse ◽  
Muscle Cells ◽  
Skeletal Muscle Cells ◽  
Negative Feedback Regulation ◽  
Chemokine Production

Physical exercise triggers the release of several cytokines/chemokines from working skeletal muscles, but the underlying mechanism(s) by which skeletal muscles decipher and respond to highly complex contractile stimuli remains largely unknown. In an effort to investigate the regulatory mechanisms of the expressions of two contraction-inducible CXC chemokines, CXCL1/KC and CXCL5/LIX, in contracting skeletal muscle cells, we took advantage of our in vitro exercise model using highly developed contractile C2C12 myotubes, which acquire properties similar to those of in vivo skeletal muscle via manipulation of Ca2+ transients with electric pulse stimulation (EPS). Production of these CXC chemokines was immediately augmented by EPS-evoked contractile activity in a manner dependent on the activities of JNK and NF-κB, but not p38, ERK1/2, or calcineurin. Intriguingly, exposure of myotubes to cyclic mechanical stretch also induced expression of these CXC chemokines; however, a much longer period of stimulation (∼12 h) was required, despite rapid JNK phosphorylation. We also demonstrate herein that CXCL1/KC and CXCL5/LIX have the ability to raise intracellular Ca2+ concentrations via CXCR2-mediated activation of pertussis toxin-sensitive Gαi proteins in C2C12 myoblasts, an action at least partially responsible for their migration and differentiation. Although we revealed a possible negative feedback regulation of their own production in response to the contractile activity in differentiated myotubes, exogenous administration of these CXC chemokines did not acutely influence either insulin-induced Akt phosphorylation or GLUT4 translocation in C2C12 myotubes. Taken together, these data shed light on the fundamental characteristics of contraction-inducible CXC chemokine production and their potential roles in skeletal muscle cells.

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