Noradrenaline release in skeletal muscle and in adipose tissue studied by microdialysis

1991 ◽  
Vol 80 (6) ◽  
pp. 595-598 ◽  
Author(s):  
Bo Grønlund ◽  
Arne Astrup ◽  
Peter Bie ◽  
Niels Juel Christensen
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Noradrenaline Release ◽  
Perfusion Medium ◽  
Blood Concentrations ◽  
Arterial Blood ◽  
Noradrenaline Concentration ◽  
Arterial Plasma ◽  
Noradrenaline Levels

1. In adipose tissue and in skeletal muscle the extracellular noradrenaline levels were studied by microdialysis in the conscious dog and compared with the noradrenaline concentration in arterial plasma. 2. The experiments were performed with and without tyramine added to the perfusion medium, and noradrenaline was measured by a sensitive radioenzymic assay. 3. In the absence of tyramine, the interstitial noradrenaline levels in adipose tissue and skeletal muscles were similar to arterial blood concentrations, provided that the former were corrected for recovery. The recovery estimated from experiments in vitro averaged 16% at room temperature. 4. With tyramine added to the perfusates, noradrenaline levels increased 10-fold. Arterial noradrenaline concentrations did not change, indicating that noradrenaline was released only locally in the tissue. 5. Our results indicate that the microdialysis technique combined with a sensitive assay for measuring noradrenaline may be applicable to the assessment of local noradrenaline release in adipose tissue and in skeletal muscle. This may be of interest, especially in adipose tissue during physiological stimulation in which sympathetic activity is difficult to evaluate by other techniques.

Fasting and diabetes alter adipose tissue glycogen synthase

1984 ◽  
Vol 247 (5) ◽  
pp. E581-E584
Author(s):  
H. R. Kaslow ◽  
R. D. Eichner
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Enzyme Purification ◽  
Glycogen Synthase ◽  
Streptozotocin Diabetes ◽  
Positive Cooperativity ◽  
Maximal Activation ◽  
Glucose Incorporation ◽  
Glycogen Synthase Activity

In a previous report (J. Biol. Chem. 254: 4678-4683, 1979), we showed that fasting blunted the ability of insulin to promote glucose incorporation into glycogen in vitro. In addition, we showed that glycogen synthase activity was altered in two ways: the concentration of glucose 6-P causing half-maximal activation increased, and positive cooperativity appeared in the glucose 6-P activation of the enzyme. We now show that streptozotocin-diabetes causes the same changes in glucose incorporation and glycogen synthase activity. We show that these changes in glycogen synthase activity persist during enzyme purification; thus it is likely the changes are a result of a structural alteration of the enzyme. Because glycogenolysis of a glycogen particle from rabbit skeletal muscle also caused the appearance of positive cooperativity, we propose that both phosphorylation and glycogenolysis are involved in the appearance of positive cooperativity.

scholarly journals IL-4 and SDF-1 Increase Adipose Tissue-Derived Stromal Cell Ability to Improve Rat Skeletal Muscle Regeneration

2020 ◽  
Vol 21 (9) ◽  
pp. 3302
Author(s):  
Małgorzata Zimowska ◽  
Karolina Archacka ◽  
Edyta Brzoska ◽  
Joanna Bem ◽  
Areta M. Czerwinska ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Muscle Regeneration ◽  
Structure And Function ◽  
Skeletal Muscle Regeneration ◽  
Stem Cell Markers ◽  
Myogenic Factors ◽  
And Function

Skeletal muscle regeneration depends on the satellite cells, which, in response to injury, activate, proliferate, and reconstruct damaged tissue. However, under certain conditions, such as large injuries or myopathies, these cells might not sufficiently support repair. Thus, other cell populations, among them adipose tissue-derived stromal cells (ADSCs), are tested as a tool to improve regeneration. Importantly, the pro-regenerative action of such cells could be improved by various factors. In the current study, we tested whether IL-4 and SDF-1 could improve the ability of ADSCs to support the regeneration of rat skeletal muscles. We compared their effect at properly regenerating fast-twitch EDL and poorly regenerating slow-twitch soleus. To this end, ADSCs subjected to IL-4 and SDF-1 were analyzed in vitro and also in vivo after their transplantation into injured muscles. We tested their proliferation rate, migration, expression of stem cell markers and myogenic factors, their ability to fuse with myoblasts, as well as their impact on the mass, structure and function of regenerating muscles. As a result, we showed that cytokine-pretreated ADSCs had a beneficial effect in the regeneration process. Their presence resulted in improved muscle structure and function, as well as decreased fibrosis development and a modulated immune response.

A negative arterial-portal venous glucose gradient decreases skeletal muscle glucose uptake

1998 ◽  
Vol 275 (1) ◽  
pp. E101-E111 ◽  
Author(s):  
Pietro Galassetti ◽  
Masakazu Shiota ◽  
Brad A. Zinker ◽  
David H. Wasserman ◽  
Alan D. Cherrington
Keyword(s):  
Skeletal Muscle ◽  
Glucose Uptake ◽  
External Iliac Artery ◽  
Baseline Period ◽  
Glucose Infusion ◽  
Whole Body ◽  
Arterial Blood ◽  
Arterial Plasma ◽  
Arterial Blood Glucose ◽  
Venous Glucose

The effect of a negative arterial-portal venous (a-pv) glucose gradient on skeletal muscle and whole body nonhepatic glucose uptake was studied in 12 42-h-fasted conscious dogs. Each study consisted of a 110-min equilibration period, a 30-min baseline period, and two 120-min hyperglycemic (2-fold basal) periods (either peripheral or intraportal glucose infusion). Somatostatin was infused along with insulin (3 × basal) and glucagon (basal). Catheters were inserted 17 days before studies in the external iliac artery and hepatic, portal and common iliac veins. Blood flow was measured in liver and hindlimb using Doppler flow probes. The arterial blood glucose, arterial plasma insulin, arterial plasma glucagon, and hindlimb glucose loads were similar during peripheral and intraportal glucose infusions. The a-pv glucose gradient (in mg/dl) was 5 ± 1 during peripheral and −18 ± 3 during intraportal glucose infusion. The net hindlimb glucose uptakes (in mg/min) were 5.0 ± 1.2, 20.4 ± 4.5, and 14.8 ± 3.2 during baseline, peripheral, and intraportal glucose infusion periods, respectively ( P < 0.01, peripheral vs. intraportal); the hindlimb glucose fractional extractions (in %) were 2.8 ± 0.4, 4.7 ± 0.8, and 3.9 ± 0.5 during baseline, peripheral, and intraportal glucose infusions, respectively ( P < 0.05, peripheral vs. intraportal). The net whole body nonhepatic glucose uptakes (in mg ⋅ kg−1⋅ min−1) were 1.6 ± 0.1, 7.9 ± 1.3, and 5.4 ± 1.1 during baseline, peripheral, and intraportal glucose infusion, respectively ( P < 0.05, peripheral vs. intraportal). In the liver, net glucose uptake was 70% greater during intraportal than during peripheral glucose infusion (5.8 ± 0.7 vs. 3.4 ± 0.4 mg ⋅ kg−1⋅ min−1). In conclusion, despite comparable glucose loads and insulin levels, hindlimb and whole body net nonhepatic glucose uptake decreased significantly during portal venous glucose infusion, suggesting that a negative a-pv glucose gradient leads to an inhibitory signal in nonhepatic tissues, among which skeletal muscle appears to be the most important.

scholarly journals The Extract of Arctium lappa L. Fruit (Arctii Fructus) Improves Cancer-Induced Cachexia by Inhibiting Weight Loss of Skeletal Muscle and Adipose Tissue

Nutrients ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3195
Author(s):  
Yo-Han Han ◽  
Jeong-Geon Mun ◽  
Hee Dong Jeon ◽  
Dae Hwan Yoon ◽  
Byung-Min Choi ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Weight Loss ◽  
Adipose Tissue ◽  
Cancer Cachexia ◽  
Uncoupling Protein ◽  
Body Weight Loss ◽  
In Vivo Experiments ◽  
Wasting Syndrome

Background: Cachexia induced by cancer is a systemic wasting syndrome and it accompanies continuous body weight loss with the exhaustion of skeletal muscle and adipose tissue. Cancer cachexia is not only a problem in itself, but it also reduces the effectiveness of treatments and deteriorates quality of life. However, effective treatments have not been found yet. Although Arctii Fructus (AF) has been studied about several pharmacological effects, there were no reports on its use in cancer cachexia. Methods: To induce cancer cachexia in mice, we inoculated CT-26 cells to BALB/c mice through subcutaneous injection and intraperitoneal injection. To mimic cancer cachexia in vitro, we used conditioned media (CM), which was CT-26 colon cancer cells cultured medium. Results: In in vivo experiments, AF suppressed expression of interleukin (IL)-6 and atrophy of skeletal muscle and adipose tissue. As a result, the administration of AF decreased mortality by preventing weight loss. In adipose tissue, AF decreased expression of uncoupling protein 1 (UCP1) by restoring AMP-activated protein kinase (AMPK) activation. In in vitro model, CM increased muscle degradation factors and decreased adipocytes differentiation factors. However, these tendencies were ameliorated by AF treatment in C2C12 myoblasts and 3T3-L1 cells. Conclusion: Taken together, our study demonstrated that AF could be a therapeutic supplement for patients suffering from cancer cachexia.

Ascorbate prevents microvascular dysfunction in the skeletal muscle of the septic rat

2001 ◽  
Vol 90 (3) ◽  
pp. 795-803 ◽  
Author(s):  
John Armour ◽  
Karel Tyml ◽  
Darcy Lidington ◽  
John X. Wilson
Keyword(s):  
Blood Pressure ◽  
Skeletal Muscle ◽  
Cecal Ligation ◽  
Microvascular Dysfunction ◽  
Sprague Dawley ◽  
Arterial Blood ◽  
Sprague Dawley Rats ◽  
Plasma Ascorbate ◽  
Ascorbate Concentration

Septic patients have low plasma ascorbate concentrations and compromised microvascular perfusion. The purpose of the present experiments was to determine whether ascorbate improves capillary function in volume-resuscitated sepsis. Cecal ligation and perforation (CLP) was performed on male Sprague-Dawley rats. The concentration of ascorbate in plasma and urine, mean arterial blood pressure, and density of continuously perfused capillaries in the extensor digitorum longus muscle were measured 24 h after surgery. CLP caused a 50% decrease (from 56 ± 4 to 29 ± 2 μM) in plasma ascorbate concentration, 1,000% increase (from 46 ± 13 to 450 ± 93 μM) in urine ascorbate concentration, 20% decrease (from 115 ± 2 to 91 ± 2 mmHg) in mean arterial pressure, and 30% decrease (from 24 ± 1 to 17 ± 1 capillaries/mm) in the density of perfused capillaries, compared with time-matched controls. A bolus of intravenous ascorbate (7.6 mg/100 g body wt) administered immediately after the CLP procedure increased plasma ascorbate concentration and restored both blood pressure and density of perfused capillaries to control levels. In vitro experiments showed that ascorbate (100 μM) inhibited replication of bacteria and prevented hydrogen peroxide injury to cultured microvascular endothelial cells. These results indicate that ascorbate is lost in the urine during sepsis and that a bolus of ascorbate can prevent microvascular dysfunction in the skeletal muscle of septic animals. Our study supports the view that ascorbate may be beneficial for patients with septic syndrome.

Effects of Ethacrynic Acid on Vascular Resistance, Metabolism, and Electrolyte Flux in the Canine Gracilis Muscle

1972 ◽  
Vol 50 (10) ◽  
pp. 940-945
Author(s):  
R. J. Ogilvje ◽  
E. Mikulic
Keyword(s):  
Skeletal Muscle ◽  
Vascular Resistance ◽  
Ethacrynic Acid ◽  
Glucose Production ◽  
Gracilis Muscle ◽  
Oxygen Utilization ◽  
Blood Concentrations ◽  
Arterial Blood ◽  
Vasodilatory Effect ◽  
Electrolyte Flux

The effects of intra-arterial ethacrynic acid (EA) on vascular resistance, metabolism, and electrolyte flux was studied in the isolated denervated canine gracilis muscle perfused with a constant inflow of arterial blood. Skeletal muscle vascular resistance was markedly reduced from baseline by 25-min infusions of EA producing blood concentrations of 10−3 M but not at concentrations of 10−5 M. There were no consistent alterations in the uptake of glucose, production of lactate, or flux of potassium in the gracilis muscle during the drug infusions or 45 min postinfusion period. Venous osmolality did not change. However, the arterio venous difference for oxygen saturation across this skeletal muscle was significantly reduced by EA treatment suggesting that oxygen utilization had been inhibited. Thus, EA has a direct vasodilatory effect which is independent of measurable changes in gracilis muscle electrolyte flux or metabolism other than a possible reduction in oxygen uptake or utilization by this muscle.

Production of glutamine and utilization of glutamate by rat subcutaneous adipose tissue in vivo

1994 ◽  
Vol 266 (1) ◽  
pp. E151-E154 ◽  
Author(s):  
T. J. Kowalski ◽  
M. Watford
Keyword(s):  
Adipose Tissue ◽  
Subcutaneous Adipose Tissue ◽  
Sampling Technique ◽  
Calibration Method ◽  
Glutamine Metabolism ◽  
Whole Body ◽  
Arterial Blood ◽  
Subcutaneous Adipose

Information about adipose tissue amino acid metabolism is limited, with most data derived from studies in vitro. The purpose of this study was to further characterize the role of adipose tissue in glutamine metabolism in the rat in vivo. The extracellular concentrations of glutamine, glutamate, alanine, and ammonia were measured in the rat inguinal fat pad using a microdialysis sampling technique. A calibration method was used to accurately assess the extracellular levels of metabolites, and a comparison of these concentrations with those in arterial blood allowed determination of the net flux of each compound. The adipose tissue-arterial blood concentration differences were 122 +/- 19, 54 +/- 37, -61 +/- 21, and -28 +/- 13 microM for glutamine, alanine, glutamate, and ammonia, respectively, indicating a production of glutamine and an uptake of glutamate by subcutaneous adipose tissue. The magnitude of glutamine production suggests that adipose tissue may play a significant role in whole body glutamine homeostasis.

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