Carbohydrate Metabolism and Energy Production

Semecarpus anacardium(Bhallataka) Alters the Glucose Metabolism and Energy Production in Diabetic Rats

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2011/142978 ◽

2011 ◽

Vol 2011 ◽

pp. 1-9 ◽

Cited By ~ 5

Author(s):

Jaya Aseervatham ◽

Shanthi Palanivelu ◽

Sachdanandam Panchanadham

Keyword(s):

Skeletal Muscle ◽

Glucose Metabolism ◽

Carbohydrate Metabolism ◽

Energy Production ◽

Antioxidative Activity ◽

Tca Cycle ◽

Diabetic Rats ◽

Semecarpus Anacardium ◽

Experimental Animals ◽

Liver And Kidney

Glucose produced by gluconeogenesis and glycogenolysis plays an important role in aggravating hyperglycemia in diabetes, and altered mitochondrial function is associated with impaired energy production. The present study focuses on the effect ofSemecarpus anacardiumon carbohydrate metabolism and energy production in diabetic rats. Diabetes was induced by the administration of Streptozotocin at a dose of 50 mg/kg.b.wt. Three days after the induction,Semecarpus anacardiumat a dose of 300 mg/kg.b.wt was administered for 21 days. After the experimental duration, the activities of the enzymes involved in Glycolysis, TCA cycle, gluconeogenesis, and glycogen were assayed in the liver and kidney of the experimental animals. In addition, to the complexes the protein expression of AKT and PI3K were assayed. The levels of the enzymes involved in Glycolysis and TCA cycle increased, while that of gluconeogensis decreased. The activities of the mitochondrial complexes were also favorably modulated. The expressions of PI3K and AKT also increased in the skeletal muscle. These effects may be attributed to the hypoglycemic and the antioxidative activity ofSemecarpus anacardium. The results of the study revealed thatSemecarpus anacardiumwas able to restore the altered activities of the enzymes involved in carbohydrate metabolism and energy production.

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Intermediary carbohydrate metabolism in protoscoleces ofEchinococcus granulosus(horse and sheep strains) andE. multilocularis

Parasitology ◽

10.1017/s0031182000044899 ◽

1982 ◽

Vol 84 (2) ◽

pp. 351-366 ◽

Cited By ~ 53

Author(s):

D. P. McManus ◽

J. D. Smyth

Keyword(s):

Steady State ◽

Carbohydrate Metabolism ◽

Pyruvate Kinase ◽

Energy Production ◽

Alternative Energy ◽

Phosphoenolpyruvate Carboxykinase ◽

Tricarboxylic Acid Cycle ◽

Tricarboxylic Acid ◽

Acid Cycle ◽

State Content

SUMMARYWith few exceptions, the specific activities of the glycolytic enzymes and the steady-state content of glycolytic and associated intermediates in protoscoleces of the horse (E.g.H) and sheep (E.g.S) strains ofEchinococcus granulosusand the closely relatedE. multilocularis(E.m.) are very similar. Phosphorylase, hexokinase, phosphofructokinase and pyruvate kinase catalyse non-equilibrium reactions and the patterns of activity for pyruvate kinase, phosphoenolpyruvate carboxykinase and malic enzyme are similar in the three organisms. The levels of tricarboxylic acid cycle intermediates inE.g.H., E.g.S. andE.m. are of the same order as those reported in tissues with an active cycle. Each has a complete sequence of cycle enzymes but there are substantial differences between the three parasites with regard to the activity of individual enzymes, The activities of NAD and NADP-linked isocitrate dehydrogenases are significantly lower inE.g.H. than inE.g.S. and particularly inE.m. which suggests that the tricarboxylic acid cycle may play a more important role in carbohydrate metabolism and energy production in the latter parasites. Nevertheless, the three organisms utilize fermentative pathways for alternative energy production, fix carbon dioxide via phosphoenolpyruvate carboxykinase and have a partial reversed tricarboxylic acid cycle. It is speculated thatin vivomore carbon will be channelled towards oxaloacetate than pyruvate at the phosphoenolpyruvate branch point. The steady state content of ATP and the ATP/AMP ratios are low in the three organisms, suggesting a low rate of ATP utilization in each.

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Platelet Metabolism in Alcohol-related Thrombocytopenia

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649153 ◽

1974 ◽

Vol 31 (01) ◽

pp. 149-159 ◽

Cited By ~ 2

Author(s):

Dale H Cowan

Keyword(s):

Carbohydrate Metabolism ◽

Energy Production ◽

Glucose Oxidation ◽

Glucose Utilization ◽

Metabolic Response ◽

Lactate Production ◽

Metabolic Responses ◽

Platelet Dysfunction ◽

14Co2 Production

SummaryThe carbohydrate metabolism of platelets from patients with alcohol-related thrombocytopenia was studied. Rates of utilization and oxidation of 14C-glueose, 14C-lactate production, and pentose cycle activity were measured in resting platelets and in platelets stimulated with thrombin or epinephrine. The metabolism of resting platelets from patients with alcohol-related thrombocytopenia was normal but the metabolic responses to stimulation differed from normal : stimulation with thrombin was associated with subnormal 14C-lactate production and normal 14CO2 production and that with epinephrine was associated with normal 14C-lactate production and subnormal 14CO2 production. Addition of ethanol to normal platelets in vitro produced increases in 14C-glucose utilization and 14C-lactate production but not in 14C-glucose oxidation. Ethanol added to normal platelets in vitro did not affect the metabolic response to thrombin stimulation but produced a 50% reduction in the response to epinephrine. Platelet dysfunction in patients with alcohol-related thrombocytopenia is not due to quantitative abnormalities in platelet energy production. Ethanol appears, however, to alter the metabolic response to nucleotide release and degradation.

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Differential modulation of glucose, lactate, and pyruvate oxidation by insulin and dichloroacetate in the rat heart

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.01117.2002 ◽

2003 ◽

Vol 285 (1) ◽

pp. H163-H172 ◽

Cited By ~ 55

Author(s):

Steven Lloyd ◽

Charlye Brocks ◽

John C. Chatham

Keyword(s):

Carbohydrate Metabolism ◽

Rat Heart ◽

Energy Production ◽

Tca Cycle ◽

Total Carbohydrate ◽

Lactate Oxidation ◽

Beneficial Effects ◽

Pyruvate Oxidation ◽

Lactate And Pyruvate

Despite the fact that lactate and pyruvate are potential substrates for energy production in vivo, our understanding of the control and regulation of carbohydrate metabolism is based principally on studies where glucose is the only available carbohydrate. Therefore, the purpose of this study was to determine the contributions of lactate, pyruvate, and glucose to energy production in the isolated, perfused rat heart over a range of insulin concentrations and after activation of pyruvate dehydrogenase with dichloroacetate (DCA). Hearts were perfused with physiological concentrations of [1-13C]glucose, [U-13C]lactate, [2-13C]pyruvate, and unlabeled palmitate for 45 min. Hearts were freeze clamped, and 13C NMR glutamate isotopomer analysis was performed on tissue extracts. Glucose, lactate, and pyruvate all contributed significantly to myocardial energy production; however, in the absence of insulin, glucose contributed only 25–30% of total pyruvate oxidation. Even under conditions where carbohydrates represented >95% of substrate entering the tricarboxylic acid (TCA) cycle, we found that glucose contributed at most 50–60% of total carbohydrate oxidation. Despite being present at only 0.1 mM, pyruvate contributed between ∼10% and 30% of total acetyl-CoA entry into the TCA cycle. We also found that insulin and DCA not only increased glucose oxidation but also exogenous pyruvate oxidation; however, lactate oxidation was not increased. The differential effects of insulin and DCA on pyruvate and lactate oxidation provide further evidence for compartmentation of cardiac carbohydrate metabolism. These results may have important implications for understanding the mechanisms underlying the beneficial effects of increasing cardiac carbohydrate metabolism.

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Mitochondrial matrix calcium ions regulate energy production in myocardium: A cytochemical study

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100134429 ◽

1990 ◽

Vol 48 (2) ◽

pp. 166-167

Author(s):

W.A. Jacob ◽

R. Hertsens ◽

A. Van Bogaert ◽

M. De Smet

Keyword(s):

Energy Metabolism ◽

Calcium Ions ◽

Energy Production ◽

Regulation Of Respiration ◽

Free Calcium ◽

Mitochondrial Matrix ◽

Cytochemical Study ◽

Nmr Techniques

In the past most studies of the control of energy metabolism focus on the role of the phosphorylation potential ATP/ADP.Pi on the regulation of respiration. Studies using NMR techniques have demonstrated that the concentrations of these compounds for oxidation phosphorylation do not change appreciably throughout the cardiac cycle and during increases in cardiac work. Hence regulation of energy production by calcium ions, present in the mitochondrial matrix, has been the object of a number of recent studies.Three exclusively intramitochondnal dehydrogenases are key enzymes for the regulation of oxidative metabolism. They are activated by calcium ions in the low micromolar range. Since, however, earlier estimates of the intramitochondnal calcium, based on equilibrium thermodynamic considerations, were in the millimolar range, a physiological correlation was not evident. The introduction of calcium-sensitive probes fura-2 and indo-1 made monitoring of free calcium during changing energy metabolism possible. These studies were performed on isolated mitochondria and extrapolation to the in vivo situation is more or less speculative.

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