Beta-adrenergic receptors in skeletal muscles of ruminants: Effects of temperature and feed intake

2000 ◽  
Vol 80 (1) ◽  
pp. 79-86 ◽  
Author(s):  
E. D. Ekpe ◽  
J. A. Moibi ◽  
R. J. Christopherson
Keyword(s):  
Skeletal Muscle ◽  
Plasma Membrane ◽  
Feed Intake ◽  
Adrenergic Receptors ◽  
Experimental Treatment ◽  
Biceps Femoris ◽  
Effect Of Temperature ◽  
Feed Restriction ◽  
Binding Affinities ◽  
Effects Of Temperature

Adrenergic receptors mediate effects of catecholamines on physiological processes including protein and energy metabolism. We determined the effects of temperature and feed intake on beta-1 and beta-2 adrenergic receptors (β1 AR and β2 AR) in skeletal muscle of lambs to assess the potential to modify physiological responses through adrenergic receptors. Twenty-four wether lambs received either restricted (R) or ad libitum (A) levels of feed intake, and were exposed to either cold (C; 0 ± 2 °C) or warm (W; 23 ± 2 °C) temperatures, resulting in four experimental treatment groups (WA, WR, CA and CR). At the end of 4 mo the lambs were slaughtered and biceps femoris, semitendinosus and gastrocnemius muscles were harvested for isolation of plasma membrane. Binding of [3H]dihydroalprenolol to crude plasma membrane was used to determine the β AR densities and binding affinities (Kd). The densities of β1 AR were 28.02 ± 4.17, 40.68 ± 2.26, 28.99 ± 4.68 and 55.56 ± 6.05 fmol mg−1 protein for biceps femoris, 29.35 ± 1.49, 35.34 ± 2.59, 28.36 ± 2.94 and 37.89 ± 3.30 fmol mg−1 protein for gastrocnemius, and 22.66 ± 2.66, 31.21 ± 4.65, 21.84 ± 1.81 and 38.62 ± 3.67 fmol mg−1 protein for semitendinosus, for WA, WR, CA and CR, respectively. The Kd values for all groups ranged from 1.7 to 8.5 nM for β1 AR. Feed restriction increased (P < 0.01) the density of β1 AR in both environments but there was no significant effect of temperature. β1 AR densities and binding affinities were significantly higher in biceps femoris than in gastrocnemius and semitendinosus muscles when feed intake was restricted. The densities of β2 AR ranged from 9.0 to 16.0 fmol mg−1 protein. There was no effect of treatments on the density or receptor binding affinity of β2 AR in muscles. It is concluded that feed restriction causes increased density of β1 AR in sheep and that feed restriction could potentially increase the metabolic responsiveness of skeletal muscle to elevated levels of catecholamines. Key words: Catecholamine receptors, skeletal muscle, temperature, feed

Beta-adrenergic modulation of insulin binding in skeletal muscle

1986 ◽  
Vol 250 (2) ◽  
pp. E198-E204
Author(s):  
B. Webster ◽  
S. R. Vigna ◽  
T. Paquette ◽  
D. J. Koerker
Keyword(s):  
Skeletal Muscle ◽  
Plasma Membrane ◽  
Protein Phosphatase ◽  
Adrenergic Receptors ◽  
Plasma Membranes ◽  
Acute Exercise ◽  
Insulin Binding ◽  
Beta Adrenergic Receptors ◽  
Beta Adrenergic ◽  
Adrenergic Antagonist

Both a high physiological concentration (13.1 nM) of epinephrine (E) and acute exercise (AEx) have previously been shown to increase 125I-insulin binding in skeletal muscle. To investigate the site and mechanism of the effect of epinephrine on binding and the possible link between epinephrine- and AEx-enhanced insulin binding, we measured insulin binding in three different preparations: 1) crude membranes derived from whole soleus muscle incubated in vitro with 13.1 nM E, 2) crude membranes with E present in the binding assay, and 3) purified plasma membranes with E present. Epinephrine enhanced binding in all three preparations by 169, 144, and 164%, respectively, at low concentrations of insulin but had little effect at high concentrations. Epinephrine, therefore appears to have its effect at the plasma membrane. Propranolol (10 microM), a beta-adrenergic antagonist, blocked E-enhanced insulin binding and when added to crude membranes made from soleus and extensor digitorum longus muscle of AEx rats reversed the increase in binding seen with exercise. This indicates that E-enhanced insulin binding is mediated by beta-adrenergic receptors and that AEx enhances insulin binding via beta-adrenergic receptors. Sodium orthovanadate (3 mM), a phosphotyrosyl-protein phosphatase inhibitor, also inhibited the increase in insulin binding due to E, implying that E may increase insulin binding by activating a phosphotyrosyl-protein phosphatase which decreases the phosphorylation of a plasma membrane protein, presumably the insulin receptor.

Effect of temperature during the synthesis process of CdSe nanoparticles using the colloidal technique

MRS Advances ◽  
2020 ◽  
Vol 5 (63) ◽  
pp. 3389-3395
Author(s):  
R. González-Díaz ◽  
D. Fernández-Sánchez ◽  
P. Rosendo-Francisco ◽  
G. Sánchez-Legorreta
Keyword(s):  
Scanning Tunneling Microscope ◽  
Electron Cloud ◽  
Cdse Nanoparticles ◽  
Effect Of Temperature ◽  
Synthesis Process ◽  
Scanning Tunneling ◽  
Tunneling Microscope ◽  
First Results ◽  
Effects Of Temperature ◽  
Scanning Electron

AbstractIn this work, the first results of the effects of temperature during the production of Se2- ions and the effect during the interaction of Cd2+ and Se2- ions in the synthesis process of CdSe nanoparticles are presented. The synthesis of CdSe was carried out by the colloidal technique, in the first one we used a temperature of 63 °C to produce Se2- ions and in the second one an interaction temperature of 49 °C. The samples were characterized using a Scanning Electron Microscope (SEM) and a Scanning Tunneling Microscope (STM). From the SEM micrographs it was possible to identify the thorns formation and irregular islands. STM micrographs reveal elliptical shapes with a regular electron cloud profile.

scholarly journals Norepinephrine Protects against Methamphetamine Toxicity through β2-Adrenergic Receptors Promoting LC3 Compartmentalization

2021 ◽  
Vol 22 (13) ◽  
pp. 7232
Author(s):  
Gloria Lazzeri ◽  
Carla L. Busceti ◽  
Francesca Biagioni ◽  
Cinzia Fabrizi ◽  
Gabriele Morucci ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Light Chain ◽  
Adrenergic Receptors ◽  
Cell Damage ◽  
Protective Effects ◽  
Autophagy Flux ◽  
Brain Areas ◽  
Indirect Consequence

Norepinephrine (NE) neurons and extracellular NE exert some protective effects against a variety of insults, including methamphetamine (Meth)-induced cell damage. The intimate mechanism of protection remains difficult to be analyzed in vivo. In fact, this may occur directly on target neurons or as the indirect consequence of NE-induced alterations in the activity of trans-synaptic loops. Therefore, to elude neuronal networks, which may contribute to these effects in vivo, the present study investigates whether NE still protects when directly applied to Meth-treated PC12 cells. Meth was selected based on its detrimental effects along various specific brain areas. The study shows that NE directly protects in vitro against Meth-induced cell damage. The present study indicates that such an effect fully depends on the activation of plasma membrane β2-adrenergic receptors (ARs). Evidence indicates that β2-ARs activation restores autophagy, which is impaired by Meth administration. This occurs via restoration of the autophagy flux and, as assessed by ultrastructural morphometry, by preventing the dissipation of microtubule-associated protein 1 light chain 3 (LC3) from autophagy vacuoles to the cytosol, which is produced instead during Meth toxicity. These findings may have an impact in a variety of degenerative conditions characterized by NE deficiency along with autophagy impairment.

scholarly journals Trans-Plasma Membrane Electron Transport and Ascorbate Efflux by Skeletal Muscle

Antioxidants ◽  
2017 ◽  
Vol 6 (4) ◽  
pp. 89 ◽  
Author(s):  
Amanda Eccardt ◽  
Thomas Bell ◽  
Lyn Mattathil ◽  
Rohan Prasad ◽  
Shannon Kelly ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Plasma Membrane ◽  
Electron Transport ◽  
Plasma Membrane Electron Transport

scholarly journals Sequential alterations in the diameters of capillaries in rabbit skeletal muscle following deep transverse friction - a morphometric study

2005 ◽  
Vol 61 (2) ◽  
Author(s):  
M. A. Gregory ◽  
M. N. Deane ◽  
M. Marsh
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Muscle Blood Flow ◽  
Biceps Femoris ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Biceps Femoris Muscle ◽  
Beneficial Effects ◽  
The Cross

Objective: The precise mechanisms by which massage promotes repair in injured soft tissue are unknown. Various authorshave attributed the beneficial effects of massage to vasodilation and increased skin and muscle blood flow. The aim of this study was to determine whether deep transverse friction massage (DTF) causes capillary vasodilation in untraumatised skeletal muscle. Setting: Academic institution.Interventions: Twelve New Zealand white rabbits were anaesthetised and the left biceps femoris muscle received 10 minutes of DTF. Following treatment, wedge biopsies were taken from the musclewithin 10 minutes of treatment (R1 - 4), 24 hours (R5 - 8) and 6 days(R9 - 12) after treatment. To serve as controls, similar biopsies weretaken from the right biceps femoris of animals. The samples were fixed, dehydrated and embedded in epoxy resin.Transverse sections (1µm) of muscle were cut, stained with 1% aqueous alkaline toluidine blue and examined with a light microscope using a 40X objective. Images containing capillaries were captured using an image analyser with SIS software and the cross sectional diameters of at least 60 capillaries were measured from each specimen. Main Outcome Measures: Changes in capillary diameter. Results: The mean capillary diameters in control muscle averaged 4.76 µm. DTF caused a significant immediate increase of 17.3% in cross sectional area (p<0.001), which was not significantly increased by 10.0% after 24 hours (p>0.05). Six days after treatment the cross-sectional area of the treated muscle was 7.6% smaller than the controls. Conclusions: This confirms the contention that DTF stimulates muscle blood flow immediately after treatment and this may account for its beneficial effects in certain conditions. 

Skeletal muscle beta-adrenergic receptors: variations due to fiber type and training

1984 ◽  
Vol 246 (2) ◽  
pp. E160-E167 ◽  
Author(s):  
R. S. Williams ◽  
M. G. Caron ◽  
K. Daniel
Keyword(s):  
Skeletal Muscle ◽  
Adrenergic Receptors ◽  
Fiber Type ◽  
Succinic Dehydrogenase ◽  
Oxidative Capacity ◽  
Treadmill Running ◽  
Beta Adrenergic Receptors ◽  
Control Groups ◽  
Beta Adrenergic ◽  
Physiological Importance

To determine the relationship between oxidative capacity and characteristics of beta-adrenergic receptors (beta AR) in skeletal muscle, selected biochemical variables were quantitated in particulate preparations from soleus and gastrocnemius muscle from rats subjected to 10 wk of treadmill running and from three control groups: free-fed, sedentary controls; food-restricted, pair-weighted controls; and animals trained by swimming. Beta AR density and isoproterenol-stimulated adenylate cyclase activity were considerably greater in the slow-twitch oxidative soleus muscle than in the mixed fiber type gastrocnemius in animals from each group (P less than 0.005). Succinic dehydrogenase (SDH) activity of gastrocnemius was increased 23-42% (P less than 0.05) in runners over each of the control groups, concommitantly with a 15-27% increase (P less than 0.05) in beta AR density (Bmax for binding of 125I-cyanopindolol). In 24 animals from all four treatment groups, there was a significant correlation between SDH activity and beta AR density (r = 0.68; P less than 0.001). We conclude that BAR density correlates positively with oxidative capacity in skeletal muscle, but further studies are required to determine the physiological importance of these differences.

scholarly journals Caveolin-3 Associates with Developing T-tubules during Muscle Differentiation

1997 ◽  
Vol 136 (1) ◽  
pp. 137-154 ◽  
Author(s):  
Robert G. Parton ◽  
Michael Way ◽  
Natasha Zorzi ◽  
Espen Stang
Keyword(s):  
Skeletal Muscle ◽  
Plasma Membrane ◽  
Muscle Cells ◽  
Membrane System ◽  
C2c12 Cells ◽  
Double Labeling ◽  
Specific Antibodies ◽  
T Tubules ◽  
Α1 Subunit

Caveolae, flask-shaped invaginations of the plasma membrane, are particularly abundant in muscle cells. We have recently cloned a muscle-specific caveolin, termed caveolin-3, which is expressed in differentiated muscle cells. Specific antibodies to caveolin-3 were generated and used to characterize the distribution of caveolin-3 in adult and differentiating muscle. In fully differentiated skeletal muscle, caveolin-3 was shown to be associated exclusively with sarcolemmal caveolae. Localization of caveolin-3 during differentiation of primary cultured muscle cells and development of mouse skeletal muscle in vivo suggested that caveolin-3 is transiently associated with an internal membrane system. These elements were identified as developing transverse-(T)-tubules by double-labeling with antibodies to the α1 subunit of the dihydropyridine receptor in C2C12 cells. Ultrastructural analysis of the caveolin-3– labeled elements showed an association of caveolin-3 with elaborate networks of interconnected caveolae, which penetrated the depths of the muscle fibers. These elements, which formed regular reticular structures, were shown to be surface-connected by labeling with cholera toxin conjugates. The results suggest that caveolin-3 transiently associates with T-tubules during development and may be involved in the early development of the T-tubule system in muscle.

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