Effect of catecholamines on glucose uptake and glycogenolysis in rat skeletal muscle

1985 ◽  
Vol 248 (5) ◽  
pp. C406-C409 ◽  
Author(s):  
D. A. Young ◽  
H. Wallberg-Henriksson ◽  
J. Cranshaw ◽  
M. Chen ◽  
J. O. Holloszy
Keyword(s):  
Skeletal Muscle ◽  
Sugar Transport ◽  
Beta Agonist ◽  
Sugar Uptake ◽  
Rat Skeletal Muscle ◽  
Adrenergic Control ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Alpha Agonist

The effect of catecholamines on glycogenolysis and sugar transport was evaluated in rat epitrochlearis (fast-twitch) and soleus (slow-twitch) muscles in vitro. When muscles were incubated with 0.1 microM epinephrine (both an alpha- and beta-agonist), the proportion of phosphorylase in the a form increased from 6.2 +/- 0.7 to 37.4 +/- 5.7% in epitrochlearis muscle and from 9.1 +/- 0.7 to 21.6 +/- 1.3% in soleus muscle. Both the activation of phosphorylase and the resulting glycogenolysis could be prevented by preincubation with the beta-blocker, propranolol. The effect of catecholamines on the rate of sugar transport was also examined in epitrochlearis muscle. The beta-agonist, isoproterenol, significantly depressed the rate of 3-O-methylglucose uptake, while the alpha-agonist, phenylephrine, had no effect. Inclusion of 0.1% albumin in the incubation medium increased the resting rate of sugar transport twofold. When isoproterenol + albumin were present, rather than exerting a depressive effect the catecholamine further increased the rate of sugar uptake. This increase was prevented by preincubation with propranolol. It was concluded that glycogenolysis and sugar transport in rat skeletal muscle are solely under beta-adrenergic control.

Studies of the halothane-cooling contractures of skeletal muscle

1987 ◽  
Vol 65 (4) ◽  
pp. 697-703 ◽  
Author(s):  
Roberto T. Sudo ◽  
Gisele Zapata ◽  
Guilherme Suarez-Kurtz
Keyword(s):  
Skeletal Muscle ◽  
Synergistic Effects ◽  
Rabbit Muscle ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Dose Dependent ◽  
Muscle Biopsies ◽  
Ca Homeostasis ◽  
Potential Use

The characteristics of transient contractures elicited by rapid cooling of frog or mouse muscles perfused in vitro with solutions equilibrated with 0.5–2.0% halothane are reviewed. The data indicate that these halothane-cooling contractures are dose dependent and reproducible, and their amplitude is larger in muscles containing predominantly slow-twitch type fibers, such as the mouse soleus, than in muscles in which fast-twitch fibers predominate, such as the mouse extensor digitorum longus. The halothane-cooling contractures are potentiated in muscles exposed to succinylcholine. The effects of Ca2+-free solutions, of the local anesthetics procaine, procainamide, and lidocaine, and of the muscle relaxant dantrolene on the halothane-cooling contractures are consistent with the proposal that the halothane-cooling contractures result from synergistic effects of halothane and low temperature on Ca sequestration by the sarcoplasmic reticulum. Preliminary results from skinned rabbit muscle fibers support this proposal. The halothane concentrations required for the halothane-cooling contractures of isolated frog or mouse muscles are comparable with those observed in serum of patients during general anesthesia. Accordingly, fascicles dissected from muscle biopsies of patients under halothane anesthesia for programmed surgery develop large contractures when rapidly cooled. The amplitude of these halothane-cooling contractures declined with the time of perfusion of the muscle fascicles in vitro with halothane-free physiological solutions. It is suggested that the halothane-cooling contractures could be used as a simple experimental model for the investigation of the effects of halothane on Ca homeostasis and contractility in skeletal muscle and for study of drugs of potential use in the management of the contractures associated with the halothane-induced malignant hyperthermia syndrome. It is shown that salicylates, but not indomethacin or mefenamic acid, inhibit the halothane-cooling contractures.

Diazepam reveals different rate-limiting processes in rat skeletal muscle contraction

1987 ◽  
Vol 65 (2) ◽  
pp. 272-273 ◽  
Author(s):  
Michael Chua ◽  
Angela F. Dulhunty
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Calcium Binding ◽  
Extensor Digitorum Longus ◽  
Calcium Uptake ◽  
Rat Skeletal Muscle ◽  
Skeletal Muscle Contraction ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Rate Limiting

The action of the tranquilizer diazepam on rat skeletal muscle showed that relaxation of isometric twitches is controlled by different processes in extensor digitorum longus (fast-twitch) and soleus (slow-twitch) muscles. Diazepam caused an increase in the amplitude of twitches in fibres from both muscles but increased the twitch duration only in soleus. The amplitude of fused tetani were reduced in both muscles and the rate of relaxation after the tetanus slowed by as much as 34% when the amplitude of the tetanus was reduced by only 11%. The slower tetanic relaxation indicated that calcium uptake by the sarcoplasmic reticulum was slower than normal in slow- and fast-twitch fibres. We conclude therefore that calcium uptake by the sarcoplasmic reticulum is rate limiting for twitch relaxation in slow-twitch but not fast-twitch fibres and suggest that calcium binding to parvalbumin controls relaxation in the fast fibres.

Effects of exercise and glycogen depletion on glyconeogenesis in muscle

1994 ◽  
Vol 76 (4) ◽  
pp. 1753-1758 ◽  
Author(s):  
A. Bonen ◽  
D. A. Homonko
Keyword(s):  
Skeletal Muscle ◽  
Muscle Glycogen ◽  
Extensor Digitorum Longus ◽  
Treadmill Exercise ◽  
Glycogen Depletion ◽  
Epinephrine Injection ◽  
Slow Twitch ◽  
Glycogen Repletion ◽  
Fast Twitch

In the present study, we investigated the hypotheses that 1) skeletal muscle glyconeogenesis will increase after exercise, 2) greater changes in glyconeogenesis will be observed after exercise in fast-twitch muscles than in slow-twitch muscles, and 3) glycogen repletion will reduce the rates of glyconeogenesis. Mouse soleus and extensor digitorum longus (EDL) glycogen depots were reduced to the same levels by treadmill exercise (60 min) or epinephrine injection (75 micrograms/100 g body wt ip). Untreated animals were used as controls. We were able to prevent glycogen repletion by incubating muscles in vitro with sorbitol (75 mM) and to increase glycogen concentrations in vitro by incubating muscles with glucose (75 mM). The experimental results showed that glyconeogenesis was increased by exercise (EDL, +51%; soleus, +82%) when glycogen levels were kept low. When glycogen depots were increased, the rate of glyconeogenesis was lowered in the exercised EDL (P < 0.05) but not in the soleus (P > 0.05). Reductions in muscle glycogen by epinephrine did not change the rate of glyconeogenesis in EDL, either when glycogen depots were kept low or were repleted (P > 0.05). In contrast, in the soleus, epinephrine-induced reductions in glycogen did stimulate glyconeogenesis (P < 0.05). Analyses in EDL showed that in nonexercised muscles glycogen concentrations were minimally effective in altering the rates of glyconeogenesis. A 30% decrement in glycogen increased glyconeogenesis by 5% in resting muscles, whereas the same decrement increased glyconeogenesis by 51% in exercised muscles.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Protein modification during biological aging: selective tyrosine nitration of the SERCA2a isoform of the sarcoplasmic reticulum Ca2+-ATPase in skeletal muscle

1999 ◽  
Vol 340 (3) ◽  
pp. 657-669 ◽  
Author(s):  
Rosa I. VINER ◽  
Deborah A. FERRINGTON ◽  
Todd D. WILLIAMS ◽  
Diana J. BIGELOW ◽  
Christian SCHÖNEICH
Keyword(s):  
Skeletal Muscle ◽  
Atpase Activity ◽  
Biological Aging ◽  
Tyrosine Nitration ◽  
Age Dependent ◽  
Slow Twitch Muscle ◽  
Slow Twitch ◽  
Fast Twitch

The accumulation of covalently modified proteins is an important hallmark of biological aging, but relatively few studies have addressed the detailed molecular-chemical changes and processes responsible for the modification of specific protein targets. Recently, Narayanan et al. [Narayanan, Jones, Xu and Yu (1996) Am. J. Physiol. 271, C1032-C1040] reported that the effects of aging on skeletal-muscle function are muscle-specific, with a significant age-dependent change in ATP-supported Ca2+-uptake activity for slow-twitch but not for fast-twitch muscle. Here we have characterized in detail the age-dependent functional and chemical modifications of the rat skeletal-muscle sarcoplasmic-reticulum (SR) Ca2+-ATPase isoforms SERCA1 and SERCA2a from fast-twitch and slow-twitch muscle respectively. We find a significant age-dependent loss in the Ca2+-ATPase activity (26% relative to Ca2+-ATPase content) and Ca2+-uptake rate specifically in SR isolated from predominantly slow-twitch, but not from fast-twitch, muscles. Western immunoblotting and amino acid analysis demonstrate that, selectively, the SERCA2a isoform progressively accumulates a significant amount of nitrotyrosine with age (≈ 3.5±0.7 mol/mol of SR Ca2+-ATPase). Both Ca2+-ATPase isoforms suffer an age-dependent loss of reduced cysteine which is, however, functionally insignificant. In vitro, the incubation of fast- and slow-twitch muscle SR with peroxynitrite (ONOO-) (but not NO/O2) results in the selective nitration only of the SERCA2a, suggesting that ONOO- may be the source of the nitrating agent in vivo. A correlation of the SR Ca2+-ATPase activity and covalent protein modifications in vitro and in vivo suggests that tyrosine nitration may affect the Ca2+-ATPase activity. By means of partial and complete proteolytic digestion of purified SERCA2a with trypsin or Staphylococcus aureus V8 protease, followed by Western-blot, amino acid and HPLC-electrospray-MS (ESI-MS) analysis, we localized a large part of the age-dependent tyrosine nitration to the sequence Tyr294-Tyr295 in the M4-M8 transmembrane domain of the SERCA2a, close to sites essential for Ca2+ translocation.

scholarly journals Immunoneutralization of TGFβ1 Improves Skeletal Muscle Regeneration: Effects on Myoblast Differentiation and Glycosaminoglycan Content

2009 ◽  
Vol 2009 ◽  
pp. 1-16 ◽  
Author(s):  
M. Zimowska ◽  
A. Duchesnay ◽  
P. Dragun ◽  
A. Oberbek ◽  
J. Moraczewski ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Regeneration ◽  
Skeletal Muscle Regeneration ◽  
Myoblast Differentiation ◽  
In Vitro Growth ◽  
Muscle Repair ◽  
Slow Twitch ◽  
Fast Twitch

When injured by crushing, the repair of the slow-twitch soleus rat muscle, unlike the fast-twitch EDL, is associated with fibrosis. As TGFβ1, whose activity can be controlled by glycosaminoglycans (GAG), plays a major role in fibrosis, we hypothesized that levels of TGFβ1 and GAG contents could account for this differential quality of regeneration. Here we show that the regeneration of the soleus was accompanied by elevated and more sustained TGFβ1 level than in the EDL. Neutralization of TGFβ1 effects by antibodies to TGFβ1 or its receptor TGFβ-R1 improved muscle repair, especially of the soleus muscle, increased in vitro growth of myoblasts, and accelerated their differentiation. These processes were accompanied by alterations of GAG contents. These results indicate that the control of TGFβ1 activity is important to improve regeneration of injured muscle and accelerate myoblast differentiation, in part through changes in GAG composition of muscle cell environment.

scholarly journals Localization of sarcoplasmic reticulum proteins in rat skeletal muscle by immunofluorescence.

1979 ◽  
Vol 80 (2) ◽  
pp. 372-384 ◽  
Author(s):  
A O Jorgensen ◽  
V Kalnins ◽  
D H MacLennan
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Immunofluorescent Staining ◽  
Mammalian Skeletal Muscle ◽  
Rat Skeletal Muscle ◽  
Ultrastructural Studies ◽  
Band Region ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Cryostat Sections

Ca++-Mg++-dependent ATPase and calsequestrin, the major intrinsic and extrinsic proteins, respectively, of the sarcoplasmic reticulum, were localized in cryostat sections of adult rat skeletal muscle by immunofluorescent staining and phase-contrast microscopy. Relatively high concentrations of both the ATPase and calsequestrin were found in fast-twitch myofibers while a very low concentration of the ATPase and a moderate concentration of calsequestrin were found in slow-twitch myofibers. These findings are consistent with previous biochemical studies of the isolated sarcoplasmic reticulum of slow-twitch and fast-twitch mammalian muscles. The distribution of the ATPase in muscle fibers is distinctly different from that of calsequestrin. While calsequestrin is present only near the interface between the I- and A-band regions of the sarcomere, the ATPase is found throughout the I-band region as well as in the center of the A-band region. In comparing these results with in situ ultrastructural studies of the distribution of sarcoplasmic reticulum in fast-twitch muscle, it appears that the ATPase is rather uniformly distributed throughout the sarcoplasmic reticulum while calsequestrin is almost exclusively confined to those regions of the membrane system which correspond to terminal cisternae. Fluorescent staining with these antisera was not observed in vascular smooth muscle cells present in the cryostat sections of the mammalian skeletal muscle used in this study.

Diet-induced obesity and acute hyperlipidemia reduce IκBα levels in rat skeletal muscle in a fiber-type dependent manner

2006 ◽  
Vol 290 (1) ◽  
pp. R233-R240 ◽  
Author(s):  
Bankim A. Bhatt ◽  
John J. Dube ◽  
Nikolas Dedousis ◽  
Jodie A. Reider ◽  
Robert M. O’Doherty
Keyword(s):  
Skeletal Muscle ◽  
P38 Mapk ◽  
Fiber Type ◽  
Dependent Manner ◽  
Rat Skeletal Muscle ◽  
Diet Induced Obesity ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Fat Feeding ◽  
Increased Activity

Increased activity of proinflammatory/stress pathways has been implicated in the pathogenesis of insulin resistance in obesity. However, the effects of obesity on the activity of these pathways in skeletal muscle, the major insulin-sensitive tissue by mass, are poorly understood. Furthermore, the mechanisms that activate proinflammatory/stress pathways in obesity are unknown. The present study addressed the effects of diet-induced obesity (DIO; 6 wk of high-fat feeding) and acute (6-h) hyperlipidemia (HL) in rats on activity of IKK/IκB/NF-κB c-Jun NH2-terminal kinase, and p38 MAPK in three skeletal muscles differing in fiber type [superficial vastus (Vas; fast twitch-glycolytic), soleus (Sol; slow twitch-oxidative), and gastrocnemius (Gas; mixed)]. DIO decreased the levels of the IκBα in Vas (24 ± 3%, P = 0.001, n = 8) but not in Sol or Gas compared with standard chow-fed controls. Similar to DIO, HL decreased IκBα levels in Vas (26 ± 5%, P = 0.006, n = 6) and in Gas (15 ± 4%, P = 0.01, n = 7) but not in Sol compared with saline-infused controls. Importantly, the fiber-type-dependent effects on IκBα levels could not be explained by differential accumulation of triglyceride in Sol and Vas. HL, but not DIO, decreased phospho-p38 MAPK levels in Vas (41 ± 7% P = 0.004, n = 6) but not in Sol or Gas. Finally, skeletal muscle c-Jun NH2-terminal kinase activity was unchanged by DIO or HL. We conclude that diet-induced obesity and acute HL reduce IκBα levels in rat skeletal muscle in a fiber-type-dependent manner.

Effect of colchicine on alkaline triglyceride lipase activity and triglyceride content in rat skeletal muscle

1988 ◽  
Vol 66 (12) ◽  
pp. 1555-1559 ◽  
Author(s):  
J. Gorski ◽  
W. C. Miller ◽  
W. K. Palmer ◽  
L. B. Oscai
Keyword(s):  
Skeletal Muscle ◽  
Enzyme Activity ◽  
Lipase Activity ◽  
Colchicine Treatment ◽  
Rat Skeletal Muscle ◽  
Potent Inducer ◽  
Triglyceride Content ◽  
Slow Twitch ◽  
Muscle Groups ◽  
Fast Twitch

One purpose of this study was to determine if colchicine increased intracellular alkaline triglyceride (TG) lipase activity above control levels in rat skeletal muscle. The second aim was to determine the effects of colchicine treatment on the concentration of TG in skeletal muscle. The results show that colchicine was a potent inducer of alkaline TG lipase activity, increasing enzyme activity approximately twofold in slow-twitch red, fast-twitch red, and fast-twitch white muscle types. It was found that in slow-twitch red soleus and fast-twitch red vastus, the two muscle groups with the highest levels of enzyme activity, 76% or more of enzyme activity resides in the intracellular compartment. These results provide evidence that colchicine blocks the export of alkaline TG lipase from skeletal muscle cells similar to that seen in the heart. The finding that TG were reduced at a time when enzyme activity was elevated suggests that intracellular alkaline TG lipase may be playing a role in the hydrolysis of the intramuscular TG droplet.

Effects of Exercise on Lactate Transport Into Mouse Skeletal Muscles

1994 ◽  
Vol 19 (3) ◽  
pp. 275-285 ◽  
Author(s):  
Arend Bonen ◽  
Karl J. A. McCullagh
Keyword(s):  
Skeletal Muscle ◽  
Key Words ◽  
Muscle Glycogen ◽  
Skeletal Muscles ◽  
Treadmill Exercise ◽  
Lactate Transport ◽  
Muscle Lactate ◽  
Slow Twitch ◽  
Fast Twitch

Skeletal muscle lactate transport was investigated in vitro in isolated fast-twitch (EDL) and slow-twitch soleus (Sol) skeletal muscles from control and exercised mice. Exercise (23 m/min, 8% grade) reduced muscle glycogen by 37% in EDL (p < 0.05) and by 35% in Sol muscles (p < 0.05). Lactate transport measurements (45 sec) were performed after 60 min of exercise in intact EDL and Sol muscles in vitro, at differing pH (6.5 and 7.4) and differing lactate concentrations (4 and 30 mM). Lactate transport was observed to be greater in Sol than in EDL (p < 0.05). In the exercised muscles there was a small but significant increase in lactate transport (p < 0.05). Lactate transport was greater when exogenous lactate concentrations were greater (p < 0.05) and more rapid at the lower pH (p < 0.05). These studies demonstrated that lactate transport was increased with exercise. Key words: soleus, EDL, treadmill exercise

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