Glyconeogenic and glycogenic enzymes in chronically active and normal skeletal muscle

The chronically active (pseudomyotonic) gastrocnemius muscle in the C57B16J dy2J/dy2J mouse contains both elevated lactate and glycogen as well as fibers that have high amounts of glycogen and enhanced glyconeogenic activity. In the present study we analyze the activities of some key glyconeogenic enzymes to assess the causes of elevated muscle glycogen and to determine the pathway for glycogen synthesis from lactate. Glycogen synthase, malate dehydrogenase, phosphoenolpyruvate carboxykinase, and malic enzyme were all elevated in homogenates of the chronically active muscle. Activities of glycogen phosphorylase and fructose 1,6-bisphosphatase were decreased in whole muscle homogenates. Histochemistry demonstrated that the high-glycogen fibers were typically fast-twitch glycolytic fibers that had high glycogen synthase, glycogen phosphorylase, and malic enzyme activities. Malate dehydrogenase activity followed succinate dehydrogenase activity and did not correlate to high-glycogen fibers. Thus the high-glycogen fibers have an elevated enzymatic capacity for glycogen synthesis from lactate, and the pathway may involve use of the pyruvate kinase bypass enzymes.

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Hepatic carbohydrate metabolism in the spontaneously diabetic Bio-Breeding Worcester rat

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1981.240.2.e83 ◽

1981 ◽

Vol 240 (2) ◽

pp. E83-E87 ◽

Cited By ~ 1

Author(s):

M. C. Appel ◽

A. A. Like ◽

A. A. Rossini ◽

D. B. Carp ◽

T. B. Miller

Keyword(s):

Carbohydrate Metabolism ◽

Glycogen Phosphorylase ◽

Phosphoenolpyruvate Carboxykinase ◽

Glucose Utilization ◽

Glycogen Content ◽

Glycogen Synthase ◽

Glycogen Synthesis ◽

Glucose Production ◽

Juvenile Onset ◽

Beta Cell Destruction

The effects of diabetes on hepatic carbohydrate metabolism were investigated in spontaneously diabetic Bio-Breeding Worcester (BB/W) rats. The juvenile-onset-type syndrome displayed by these animals is characterized by beta-cell destruction with subsequent ketosis-prone insulinopenia. Livers from diabetic animals demonstrated increased adenosine 3',5'-cyclic monophosphate levels but subnormal total protein and glycogen content. Isolated perfused livers of diabetic BB/W rats demonstrated an increased rate of glucose production from [14C]lactate and an impaired rate of glycogen synthesis. These data were consonant with hepatic enzyme studies demonstrating markedly increased activities of component gluconeogenic (glucose-6-phosphatase, fructose-1,6-diphosphatase, phosphoenolpyruvate carboxykinase) and glycogenolytic (glycogen phosphorylase) enzymes with decreased activities of glycolytic (hexokinase, pyruvate kinase) and glycogenic (glycogen synthase) enzymes. These findings agree with previous studies using alloxan- and streptozotocin-induced diabetic animals and suggest that accelerated hepatic gluconeogenesis and impaired glucose utilization are pathognomonic of all insulin-deficient diabetic syndromes.

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Immunocytochemical detection of hepatic carbohydrate metabolic enzymes: Improved resolution with polyethylene glycol embedding and visio-bond semithin sections

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100124367 ◽

1992 ◽

Vol 50 (1) ◽

pp. 792-793

Author(s):

Kuixiong Gao ◽

Randal E. Morris ◽

Bruce F. Giffin ◽

Robert R. Cardell

Keyword(s):

Polyethylene Glycol ◽

Glycogen Phosphorylase ◽

Phosphoenolpyruvate Carboxykinase ◽

Glycogen Synthase ◽

Metabolic Enzymes ◽

Silver Stain ◽

Accurate Localization ◽

Immunocytochemical Detection ◽

Semithin Sections ◽

Parenchymal Cells

Several enzymes are involved in the regulation of anabolic and catabolic pathways of carbohydrate metabolism in liver parenchymal cells. The lobular distribution of glycogen synthase (GS), phosphoenolpyruvate carboxykinase (PEPCK) and glycogen phosphorylase (GP) was studied by immunocytochemistry using cryosections of normal fed and fasted rat liver. Since sections of tissue embedded in polyethylene glycol (PEG) show good morphological preservation and increased detectability for immunocytochemical localization of antigenic sites, and semithin sections of Visio-Bond (VB) embedded tissue provide higher resolution of cellular structure, we applied these techniques and immunogold-silver stain (IGSS) for a more accurate localization of hepatic carbohydrate metabolic enzymes.

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Control of glycogen synthesis is shared between glucose transport and glycogen synthase in skeletal muscle fibers

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.2000.278.2.e234 ◽

2000 ◽

Vol 278 (2) ◽

pp. E234-E243 ◽

Cited By ~ 36

Author(s):

Iñaki Azpiazu ◽

Jill Manchester ◽

Alexander V. Skurat ◽

Peter J. Roach ◽

John C. Lawrence

Keyword(s):

Skeletal Muscle ◽

Glucose Transport ◽

Glycogen Synthase ◽

Glycogen Synthesis ◽

Muscle Fibers ◽

Fiber Types ◽

Oxidative Potential ◽

Glycogen Accumulation ◽

Tibialis Muscle ◽

Fast Twitch

The effects of transgenic overexpression of glycogen synthase in different types of fast-twitch muscle fibers were investigated in individual fibers from the anterior tibialis muscle. Glycogen synthase was severalfold higher in all transgenic fibers, although the extent of overexpression was twofold greater in type IIB fibers. Effects of the transgene on increasing glycogen and phosphorylase and on decreasing UDP-glucose were also more pronounced in type IIB fibers. However, in any grouping of fibers having equivalent malate dehydrogenase activity (an index of oxidative potential), glycogen was higher in the transgenic fibers. Thus increasing synthase is sufficient to enhance glycogen accumulation in all types of fast-twitch fibers. Effects on glucose transport and glycogen synthesis were investigated in experiments in which diaphragm, extensor digitorum longus (EDL), and soleus muscles were incubated in vitro. Transport was not increased by the transgene in any of the muscles. The transgene increased basal [14C]glucose into glycogen by 2.5-fold in the EDL, which is composed primarily of IIB fibers. The transgene also enhanced insulin-stimulated glycogen synthesis in the diaphragm and soleus muscles, which are composed of oxidative fiber types. We conclude that increasing glycogen synthase activity increases the rate of glycogen synthesis in both oxidative and glycolytic fibers, implying that the control of glycogen accumulation by insulin in skeletal muscle is distributed between the glucose transport and glycogen synthase steps.

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Fructose-1,6-bisphosphatase, Malate Dehydrogenase, Isocitrate Lyase, Phosphoenolpyruvate Carboxykinase, Glyceraldehyde-3-phosphate Dehydrogenase, and Cyclophilin A are secreted inSaccharomyces cerevisiaegrown in low glucose

Communicative & Integrative Biology ◽

10.4161/cib.27216 ◽

2013 ◽

Vol 6 (6) ◽

pp. e27216 ◽

Cited By ~ 13

Author(s):

Bennett J Giardina ◽

Hui-Ling Chiang

Keyword(s):

Malate Dehydrogenase ◽

Phosphoenolpyruvate Carboxykinase ◽

Isocitrate Lyase ◽

Cyclophilin A ◽

Fructose 1,6 Bisphosphatase ◽

Low Glucose

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Regulation of glycogen synthesis in rat skeletal muscle after glycogen-depleting contractile activity: effects of adrenaline on glycogen synthesis and activation of glycogen synthase and glycogen phosphorylase

Biochemical Journal ◽

10.1042/0264-6021:3440231 ◽

1999 ◽

Vol 344 (1) ◽

pp. 231 ◽

Cited By ~ 14

Author(s):

Jesper FRANCH ◽

Rune ASLESEN ◽

Jørgen JENSEN

Keyword(s):

Skeletal Muscle ◽

Glycogen Phosphorylase ◽

Glycogen Synthase ◽

Contractile Activity ◽

Glycogen Synthesis ◽

Rat Skeletal Muscle

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DEHYDROGENASES DURING POSTEMBRYONIG DEVELOPMENT OF TRIBOLIUM CONFUSUM DUVAL (COLEOPTERA): I. MALATE DEHYDROGENASE AND MALIC ENZYME IN THE PARTICULATE AND SOLUBLE FRACTIONS

Canadian Journal of Biochemistry ◽

10.1139/o67-164 ◽

1967 ◽

Vol 45 (9) ◽

pp. 1393-1400 ◽

Cited By ~ 4

Author(s):

Sital Moorjani ◽

André Lemonde

Keyword(s):

Dehydrogenase Activity ◽

Malate Dehydrogenase ◽

Malic Enzyme ◽

Anaerobic Metabolism ◽

Soluble Fraction ◽

Larval Period ◽

Tribolium Confusum ◽

Sudden Increase ◽

Kinetic Behavior ◽

Soluble Fractions

Malate dehydrogenase and malic enzyme activities in the particulate (mitochondria) and soluble fraction have been determined in relation to the larval–pupal transformation of Tribolium confusum. The malate dehydrogenase activity in the soluble fraction follows a more or less inverse trend as compared with that in the particulate fraction. The malate dehydrogenase activity in the particulate and soluble fractions of the larva is attributed to different enzymes based on their electrophoretic mobility. A sudden increase in the activity of malate dehydrogenase in the soluble fraction at the end of the larval period is attributed to release of the enzyme from mitochondria by lysis. A further comparison of the larval particulate and pupal soluble malate dehydrogenase is made on the basis of their kinetic behavior. Malic enzyme is NADP-linked, although activity was also noted with NAD. The significance of the high activity of malic enzyme and malate dehydrogenase during pupation is discussed in relation to anaerobic metabolism.

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Respiration and carbohydrate energy metabolism of the lung-dwelling parasite Rhabdias bufonis (Nematoda: Rhabdiasoidea)

Parasitology ◽

10.1017/s0031182000047351 ◽

1978 ◽

Vol 76 (1) ◽

pp. 21-27 ◽

Cited By ~ 9

Author(s):

A. O. Anya ◽

G. M. Umezurike

Keyword(s):

Lactate Dehydrogenase ◽

Energy Metabolism ◽

Malate Dehydrogenase ◽

Malic Enzyme ◽

Phosphoenolpyruvate Carboxykinase ◽

Weight Basis ◽

Fresh Weight ◽

Fresh Weight Basis ◽

Alternative Pathways

SummaryAn investigation of the carbohydrate energy metabolism of Rhabdias bufonis, the lung-dwelling nematode parasite of the African toad, Bufo regularis, indicates that the nematode stores very little glycogen (0·137 ± 0·003% on a fresh weight basis) but does utilize oxygen in vitro. The intracellular distribution and high levels of activity observed for the enzymes phosphoenolpyruvate carboxykinase, pyruvate kinase, lactate dehydrogenase, malate dehydrogenase, malic enzyme and fumarate reductase suggest two alternative pathways of carbohydrate energy metabolism.

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Nitric oxide inhibits glycogen synthesis in isolated rat hepatocytes

Biochemical Journal ◽

10.1042/bj3301045 ◽

1998 ◽

Vol 330 (2) ◽

pp. 1045-1049 ◽

Cited By ~ 50

Author(s):

Fleur SPRANGERS ◽

P. Hans SAUERWEIN ◽

A. Johannes ROMIJN ◽

M. George van WOERKOM ◽

J. Alfred MEIJER

Keyword(s):

Nitric Oxide ◽

Glucose Metabolism ◽

Phosphoenolpyruvate Carboxykinase ◽

Glycogen Synthase ◽

Glycogen Synthesis ◽

Rat Hepatocytes ◽

Inhibitory Effect ◽

No Donor ◽

Isolated Rat Hepatocytes ◽

Intracellular Glucose

There is increasing evidence for the existence of intrahepatic regulation of glucose metabolism by Kupffer cell products. Nitric oxide (NO) is known to inhibit gluconeogenic flux through pyruvate carboxylase and phosphoenolpyruvate carboxykinase. However, NO may also influence glucose metabolism at other levels. Using hepatocytes from fasted rats incubated with the NO-donor S-nitroso-N-acetylpenicillamine, we have now found that the synthesis of glycogen from glucose is even more sensitive to inhibition by NO than gluconeogenesis. Inhibition of glycogen production by NO was accompanied by a rise in intracellular glucose 6-phosphate and UDPglucose. Activity of glycogen synthase, as measured in extracts of hepatocytes after the cells had been exposed to NO, was decreased. Experiments with gel-filtered liver extracts revealed that inhibition of glycogen synthase was caused by an inhibitory effect of NO on the conversion of glycogen synthase b into glycogen synthase a.

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Amylin impairment of insulin effects on glycogen synthesis and phosphoenolpyruvate carboxykinase gene expression in rat primary cultured hepatocytes

Biochemical Journal ◽

10.1042/bj3040449 ◽

1994 ◽

Vol 304 (2) ◽

pp. 449-453 ◽

Cited By ~ 4

Author(s):

S Baqué ◽

J J Guinovart ◽

A M Gómez-Foix

Keyword(s):

Gene Expression ◽

Phosphoenolpyruvate Carboxykinase ◽

Glycogen Synthase ◽

Glycogen Synthesis ◽

Mrna Level ◽

Rat Hepatocytes ◽

Synthesis Rate ◽

Cultured Hepatocytes ◽

Glycogen Accumulation ◽

Primary Cultured Hepatocytes

The ability of amylin to impair hepatic insulin action is controversial. We have found that the effect of amylin in primary cultured hepatocytes is strongly dependent on the culture conditions. Only in hepatocytes preincubated in the presence of fetal serum did amylin, at concentrations ranging from 1 to 100 nM, reduce insulin-stimulated glycogen synthesis rate and glycogen accumulation without showing direct effects. Neither basal glycogen synthase nor glycogen phosphorylase activity was modified by amylin treatment. Nevertheless, amylin (100 nM) blocked the activation of glycogen synthase by insulin. Amylin also proved capable of opposing the reduction in the expression of the phosphoenolpyruvate carboxykinase (PEPCK) gene induced by insulin, whereas the basal mRNA level of PEPCK was unaffected by amylin treatment. Thus, these results show that, in cultured rat hepatocytes, amylin is indeed able to interfere with insulin regulation of glycogenesis and PEPCK gene expression, favouring the hypothesis that amylin may modulate liver sensitivity to insulin.

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