scholarly journals The influence of insulin and of contraction on glucose metabolism in the perfused diaphragm muscle from normal and streptozotocin-treated rats

1971 ◽  
Vol 125 (1) ◽  
pp. 97-103 ◽  
Author(s):  
Anne Beloff-Chain ◽  
E. B. Chain ◽  
K. A. Rookledge
Keyword(s):  
Glucose Metabolism ◽  
Glycogen Synthesis ◽  
Lactate Production ◽  
Diaphragm Muscle ◽  
Co2 Production ◽  
Experimental Conditions ◽  
Contracting Muscle ◽  
Hexose Phosphate ◽  
Muscle Formation ◽  
Resting Muscle

1. The metabolism of [U-14C]glucose in perfused resting and contracting diaphragm muscle from normal rats and rats made diabetic with streptozotocin was studied in the presence and absence of insulin. 2. The incorporation of [U-14C]-glucose into glycogen and oligosaccharides was stimulated by insulin under all experimental conditions studied. 3. In the normal perfused resting diaphragm muscle the incorporation of radioactivity from [14C]glucose into lactate and CO2 was not affected by insulin. 4. Periodic contractions, induced by electrical stimulation of the perfused diaphragm muscle in the absence of insulin, caused an increased incorporation of 14C into glycogen and hexose phosphate esters, whereas incorporation of 14C into lactate was greatly decreased. Production of 14CO2 in the contracting muscle was not significantly different from that in resting muscle. Addition of insulin to the perfusion liquid caused a further increase in formation of [14C]-glycogen in contracting muscle to values reached in the resting muscle in the presence of insulin. Formation of [14C]lactate was also stimulated by insulin, to values close to those found in the resting muscle in the presence of insulin. 5. In the diabetic resting muscle the rate of glucose metabolism was very low in the absence of insulin. Insulin increased formation of [14C]glycogen to the value found in normal muscle in the absence of insulin. Production of 14CO2 and formation of [14C]hexose phosphate remained unchanged. 6. In the diabetic contracting muscle production of 14CO2 was increased to values approaching those found in normal contracting muscle. Formation of [14C]lactate and [14C]glycogen was also increased by contraction, to normal values. Only traces of [14C]hexose phosphate were detectable. Addition of insulin to the perfusion medium stimulated formation of [14C]glycogen, to values found in normal contracting muscle. Production of [14C]hexose phosphate was stimulated by insulin, to approximately the values found in the normal contracting muscle. Production of 14CO2 and [14C]lactate, however, was not significantly affected by insulin. 7. These results indicate that the defects of glucose metabolism observed in perfused resting diabetic diaphragm muscle can be partially corrected by contraction, and in the presence of insulin the contracting diabetic muscle has a completely normal pattern of glycogen synthesis and lactate production, but CO2 production remains impaired.

Energetic effects of adenosine on vascular smooth muscle

2000 ◽  
Vol 278 (1) ◽  
pp. H26-H32 ◽  
Author(s):  
John T. Barron ◽  
Liping Gu
Keyword(s):  
Smooth Muscle ◽  
Glucose Metabolism ◽  
Vascular Smooth Muscle ◽  
Muscle Tone ◽  
Tricarboxylic Acid Cycle ◽  
Glycogen Synthesis ◽  
Lactate Production ◽  
Metabolic Effects ◽  
Hypoxic Conditions ◽  
Resting Muscle

Adenosine (Ado) is a naturally occurring compound that has several important cardiovascular actions, including activation of ATP-sensitive K+ channels in vascular smooth muscle, vasorelaxation, and an effect to alter glucose metabolism of cardiac muscle. The metabolic effects of Ado on vascular smooth muscle have not been defined and were examined in this study. Porcine carotid artery strips were incubated in the presence and absence of 0.5 mM Ado. Compared with the control, Ado had no effect on glucose uptake, glucose oxidation, or fatty acid (octanoate) oxidation. Ado suppressed glycolysis but enhanced glycogen synthesis. Relative to the rate of glycolysis, Ado increased lactate production. Ado stimulated O2 consumption by 52 ± 10%, altered the activities of the tricarboxylic acid cycle and malate-aspartate shuttle, and increased the content of ATP, ADP, AMP, and phosphocreatine. Alteration in the metabolic variables by Ado could not be attributed to diminished energy requirements of reduced resting muscle tone of the arterial strips. Relaxation of the arterial strips in response to Ado were abolished in arteries incubated under hypoxic conditions (95% N2-5% CO2). Hypoxia was associated with increased ADP content. It is concluded that Ado affected glucose metabolism indirectly. The metabolic and energetic effects of 0.5 mM Ado are mediated by alterations in the concentrations of AMP, ATP, and phosphorylation potential (ATP/ADP).

Alterations of glucose metabolism during perfusion of rat lung with paraquat.

1978 ◽  
Vol 234 (6) ◽  
pp. E653 ◽  
Author(s):  
D J Bassett ◽  
A B Fisher
Keyword(s):  
Glucose Metabolism ◽  
Redox State ◽  
Glucose Utilization ◽  
Lactate Production ◽  
Mitochondrial Metabolism ◽  
Co2 Production ◽  
Bicarbonate Buffer ◽  
Enzymatic Reduction ◽  
14Co2 Production ◽  
Pyruvate Ratio

Isolated perfused rat lungs were used to investigate effects of paraquat on lung glucose metabolism. Lungs were ventilated with 5% CO2 in air and perfused with Krebs-Ringer bicarbonate buffer, pH 7.4, containing albumin and 5.5 mM radiolabeled D-glucose. Control lung glucose utilization, estimated from rate of 3H2O production from [5-3H]glucose, was 44 mumol/h-g dry wt. Pentose cycle activity, based on 14CO2 specific yields at the end of perfusions with [1-14C]- and [6-14C]glucose, was 14% of glucose utilization. During perfusion with 1.5 mM paraquat, glucose utilization increased 28%, 14CO2 production via the pentose cycle increased 182% (P less than 0.005), CO2 production via mitochondrial metabolism increased 39% (P less than 0.02), and the rate of lactate production increased 28% (P less than 0.05). Pyruvate production and the lactate-to-pyruvate ratio were not significantly altered. The data indicate that interaction of paraquat with the lung results in increased turnover of cytoplasmic NADPH and increased mitochondrial metabolism, but no significant change in cytoplasmic redox state. The findings are compatible with intracellular enzymatic reduction of paraquat by an NADPH-requiring reductase.

Evidence for a hormonal action of beta-endorphin to increase glucose uptake in resting and contracting skeletal muscle

1997 ◽  
Vol 155 (2) ◽  
pp. 387-392 ◽  
Author(s):  
AA Evans ◽  
S Khan ◽  
ME Smith
Keyword(s):  
Skeletal Muscle ◽  
Muscular Activity ◽  
Optimum Concentration ◽  
Diaphragm Muscle ◽  
Contracting Muscle ◽  
Beta Endorphin ◽  
Increase Glucose Uptake ◽  
Hormonal Action ◽  
Resting Muscle ◽  
Stimulation Of

The uptake of 2-[3H]deoxyglucose, a non-metabolisable derivative of glucose, was studied in resting and contracting muscle. An isolated phrenic nerve/hemidiaphragm preparation of the mouse was used, and contractions of the muscle were elicited by electrical stimulation of the nerve. beta-Endorphin stimulated the uptake of 2-deoxyglucose in resting diaphragm muscle. The rate of uptake in the presence of the optimum concentration of beta-endorphin was similar to that in the presence of the optimum concentration of insulin over the short incubation period. beta-Endorphin also stimulated the uptake of 2-deoxyglucose in contracting muscle, but the optimum concentration of the peptide for this effect was three orders of magnitude lower than in resting muscle. The optimum concentration for insulin, however, was similar in resting and contracting muscle. An analogue of the C-terminal tetrapeptide of beta-endorphin also stimulated 2-deoxyglucose uptake, but this peptide was equally efficacious in resting and contracting muscle. It is suggested that beta-endorphin, which is released into the circulation during exercise, may have a hormonal action to increase the uptake of glucose during muscular activity. This peptide or its metabolites may be partly responsible for the insulin-independent uptake of glucose during exercise.

scholarly journals Influence of some mononucleotides and their corresponding nucleosides on the metabolism of carbohydrates in the isolated rat diaphragm muscle

1965 ◽  
Vol 97 (2) ◽  
pp. 565-568 ◽  
Author(s):  
A Beloff-Chain ◽  
P Betto ◽  
W Bleszynski ◽  
R Catanzaro ◽  
EB Chain ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Incubation Period ◽  
Glycogen Synthesis ◽  
Diaphragm Muscle ◽  
Maximum Effect ◽  
Rat Diaphragm ◽  
Oxidation Of Glucose ◽  
Isolated Rat

1. The influence of ATP on glucose metabolism was studied in the isolated rat diaphragm; it was shown that ATP increases the oxidation of glucose and the aerobic conversion of glucose into lactate, whereas it decreases glycogen synthesis. There was no influence of ATP on the anaerobic formation of lactate from glucose. 2. A maximum effect of ATP on the oxidation of glucose (about 160% increase) was obtained in the presence of 10mm-ATP; in the presence of 2mm-ATP the effect was about 65%, and was approximately constant from 10 to 90min. incubation period. 3. In a phosphate-free tris-buffered medium the oxidation of glucose was considerably decreased, but the percentage stimulation by ATP was about the same as in a phosphate-buffered medium. 4. ATP was shown to increase the oxidation of fructose, glucose 6-phosphate, glucose 1-phosphate, fructose 1,6-diphosphate and, to a much smaller extent, pyruvate. 5. ADP stimulated the oxidation of glucose to the same extent as ATP at a concentration of 2mm and the effect with AMP was only slightly less; IMP and adenosine had only a small stimulatory effect at this concentration, whereas inosine had no effect.

scholarly journals Effects of Physiological Doses of Resveratrol and Quercetin on Glucose Metabolism in Primary Myotubes

2021 ◽  
Vol 22 (3) ◽  
pp. 1384
Author(s):  
Itziar Eseberri ◽  
Claire Laurens ◽  
Jonatan Miranda ◽  
Katie Louche ◽  
Arrate Lasa ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Glucose Metabolism ◽  
Glucose Oxidation ◽  
Glycogen Synthase ◽  
Glycogen Synthesis ◽  
Lactate Production ◽  
Acid Oxidation ◽  
Healthy Donors ◽  
Human Myotubes ◽  
Amp Activated Protein Kinase

Phenolic compounds have emerged in recent years as an option to face insulin resistance and diabetes. The central aim of this study was: (1) to demonstrate that physiological doses of resveratrol (RSV) or quercetin (Q) can influence glucose metabolism in human myotubes, (2) to establish whether AMP-activated protein kinase (AMPK) and protein kinase B –PKB- (Akt) pathways are involved in this effect. In addition, the effects of these polyphenols on mitochondrial biogenesis and fatty acid oxidation were analysed. Myotubes from healthy donors were cultured for 24 h with either 0.1 μM of RSV or with 10 μM of Q. Glucose metabolism, such as glycogen synthesis, glucose oxidation, and lactate production, were measured with D[U-14C]glucose. β-oxidation using [1–14C]palmitate as well as the expression of key metabolic genes and proteins by Real Time PCR and Western blot were also assessed. Although RSV and Q increased pgc1α expression, they did not significantly change either glucose oxidation or β-oxidation. Q increased AMPK, insulin receptor substrate 1 (IRS-1), and AS160 phosphorylation in basal conditions and glycogen synthase kinase 3 (GSK3β) in insulin-stimulated conditions. RSV tended to increase the phosphorylation rates of AMPK and GSK3β. Both of the polyphenols increased insulin-stimulated glycogen synthesis and reduced lactate production in human myotubes. Thus, physiological doses of RSV or Q may exhibit anti-diabetic actions in human myotubes.

ÉTUDE IN VITRO DU MÉTABOLISME DES HYDRATES DE CARBONE DANS LE LEUCOCYTE CIRCULANT DU COBAYE TRAITÉ À LA CORTISONE

1966 ◽  
Vol 51 (2) ◽  
pp. 193-202
Author(s):  
J. A. Antonioli ◽  
A. Vannotti
Keyword(s):  
Glucose Concentration ◽  
Intramuscular Injection ◽  
Acute Inflammation ◽  
Glycogen Content ◽  
Glycogen Synthesis ◽  
Lactate Production ◽  
Glucose Consumption ◽  
List Type ◽  
Hydrates De Carbone

ABSTRACT 1. The metabolism of suspensions of circulating leucocytes has been studied after intramuscular injection of a dose of 50 mg/kg of a corticosteroid (cortisone acetate). The suspensions were incubated under aerobic conditions in the presence of a glucose concentration of 5.6 mm. Glucose consumption, lactate production, and variations in intracellular glycogen concentration were measured. After the administration of the corticosteroid, the anabolic processes of granulocyte metabolism were reversibly stimulated. Glucose consumption and lactate production increased 12 hours after the injection, but tended to normalize after 24 hours. The glycogen content of the granulocytes was enhanced, and glycogen synthesis during the course of the incubation was greatly stimulated. The action of the administered corticosteroid is more prolonged in females than in males. The injection of the corticosteroid caused metabolic modifications which resemble in their modulations and in their chronological development those found in circulating granulocytes of guinea-pigs suffering from sterile peritonitis. These results suggest, therefore, that, in the case of acute inflammation, the glucocorticosteroids may play an important role in the regulation of the metabolism of the blood leucocytes.

Abnormal activation of glycogen synthesis in fibroblasts from NIDDM subjects. Evidence for an abnormality specific to glucose metabolism

Diabetes ◽  
1993 ◽  
Vol 42 (4) ◽  
pp. 583-589 ◽  
Author(s):  
A. M. Wells ◽  
I. C. Sutcliffe ◽  
A. B. Johnson ◽  
R. Taylor
Keyword(s):  
Glucose Metabolism ◽  
Glycogen Synthesis

Carbohydrate and Protein Supplements, an Effective Means for Maintaining Exercise-Induced Glucose Metabolism Homeostasis

2021 ◽  
Vol 11 (6) ◽  
pp. 1120-1128
Author(s):  
Dingguo Ruan ◽  
Hong Deng ◽  
Xiaoyang Xu
Keyword(s):  
Blood Glucose ◽  
Glucose Metabolism ◽  
Normal Saline ◽  
Glucose Transporter ◽  
Glycogen Synthesis ◽  
Effective Means ◽  
Recovery Period ◽  
Future Application ◽  
Glut 4 ◽  
Exercise Induced

This study aimed to verify the effects of an independently developed carbohydrate and protein (CHO+P) beverage (7.2% oligosaccharide and 1.6% soy-polypeptide) supplement on exerciseinduced glucose metabolism and associated gene expression. Mice received 1 mL/100 g body weight of normal saline (group C; n = 36) or CHO+P (group E; n = 36) at 30 min before an immediately after exercise. Mice without exercise and supplementation served as normal controls (group NC; n = 9). The expression levels related to glucose metabolism were measured at 0, 4, 12, and 24 h after exercise (n = 9 per group). The blood glucose, insulin, and liver glycogen contents in groups C and E were dramatically lower than group NC immediately after exercise. Those in group E were significantly higher than group C, with few differences between the two. Muscle glycogen was restored more quickly when the CHO+P beverage was consumed compared to normal saline. Furthermore, exercise-induced increase in glucose transporter-4 (GLUT-4) mRNA could be depressed by CHO+P supplementation but enhanced in GLUT-4 protein. Interleukin-6 (IL-6) showed a double peak curve in the recovery period, but IL-6 increased again in group E earlier than group C. These findings confirmed that the beverage has significantly improved time in maintaining blood glucose stability, reducing glycogen consumption, accelerating glycogen resynthesis, and repairing injury in rats. This study suggests the future application of this beverage in humans with experimental support and provides a scientific direction for promoting glycogen synthesis and recovery through nutrition.

Blood flow, blood oxygen tension, oxygen uptake, and oxygen transport in skeletal muscle

1964 ◽  
Vol 206 (4) ◽  
pp. 858-866 ◽  
Author(s):  
Wendell N. Stainsby ◽  
Arthur B. Otis
Keyword(s):  
Blood Flow ◽  
Oxygen Uptake ◽  
Oxygen Tension ◽  
Capillary Density ◽  
Muscle Group ◽  
Blood Oxygen ◽  
Histological Techniques ◽  
Contracting Muscle ◽  
Resting Muscle

The effect of changes in blood flow and of blood oxygen tension on oxygen uptake of the in situ gastrocnemius-plantaris muscle group of the dog was examined. Oxygen uptake by resting muscle was not altered by changes in blood flow or blood oxygen tension except when these parameters were reduced below critical values. When the muscle group was contracting once per second, changes in blood oxygen tension were similarly without effect until a critically low value was reached. Although the contracting muscle used eight times as much oxygen per minute as resting muscle, the critical oxygen tension was lower than that for resting muscle. In an attempt to explain this observation the blood-tissue oxygen tension difference was estimated and used in the Krogh equation to calculate capillary density. The capillary density in contracting muscle was found to be much greater than in resting muscle and was about the same as the capillary density measured by others by histological techniques.

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