scholarly journals Effects of denervation on the glycogen content and on the activities of enzymes of glucose and glycogen metabolism in rat diaphragm muscle

1972 ◽  
Vol 128 (4) ◽  
pp. 789-801 ◽  
Author(s):  
L. V. Turner ◽  
K. L. Manchester
Keyword(s):  
Lactate Dehydrogenase ◽  
Glycogen Phosphorylase ◽  
Glycogen Content ◽  
Specific Activity ◽  
Glycogen Metabolism ◽  
Diaphragm Muscle ◽  
Rat Diaphragm ◽  
Nerve Section ◽  
Fibre Development ◽  
Specific Activities

1. Changes in the content and concentration of glycogen and in the activity of a number of enzymes involved in glucose and glycogen metabolism were studied in the rat hemidiaphragm after unilateral denervation. 2. After nerve section the tissue hypertrophies; this hypertrophy is said to be confined to the smaller red fibres and not to the white. 3. The total hexokinase activity increases, whereas that of total glycogen phosphorylase decreases. The specific activity of phosphorylase a, determined after Halothane anaesthesia, remains fairly constant. 4. In fed animals the denervated tissue stores less glycogen, but in the early stages its glycogen content does not fall on starvation. 5. The effect of denervation on the specific activities of several other characteristically white-fibre enzymes are not consistent with the response of glycogen phosphorylase; the increase in content of glyceraldehyde 3-phosphate dehydrogenase and lactate dehydrogenase is thought to be related to proliferation of the sarcoplasmic reticulum. 6. The ratio of lactate dehydrogenase M/H subunits increases at the height of the hypertrophy, but then declines as the mass of the tissue falls. 7. The chronology of these changes in enzyme activities suggests a multiplicity of distinct responses after nerve section not consistent with any one model, either specific fibre development or reversion to de-differentiated, foetal-type metabolism.

scholarly journals The influence of nerve section on the metabolism of polyamines in rat diaphragm muscle

1981 ◽  
Vol 196 (2) ◽  
pp. 603-610 ◽  
Author(s):  
D Hopkins ◽  
K L Manchester
Keyword(s):  
Ornithine Decarboxylase ◽  
Normal Values ◽  
Methionine Adenosyltransferase ◽  
Diaphragm Muscle ◽  
Regulatory Mechanisms ◽  
Polyamine Metabolism ◽  
Decarboxylase Activity ◽  
Rat Diaphragm ◽  
Nerve Section ◽  
Adenosylmethionine Decarboxylase

Concentrations of spermidine, spermine and putrescine have been measured in rat diaphragm muscle after unilateral nerve section. The concentration of putrescine increased approx. 10-fold 2 days after nerve section, that of spermidine about 3-fold by day 3, whereas an increase in the concentration of spermine was only observed after 7-10 days. It was not possible to show enhanced uptake of either exogenous putrescine or spermidine by the isolated tissue during the hypertrophy. Consistent with the accumulation of putrescine, activity of ornithine decarboxylase increased within 1 day of nerve section, was maximally elevated by the second day and then declined. Synthesis of spermidine from [14C]putrescine and either methionine or S-adenosylmethionine bt diaphragm cytosol rose within 1 day of nerve section, but by day 3 had returned to normal or below normal values. Activity of adenosylmethionine decarboxylase similarly increased within 1 day of nerve section, but by day 3 had declined to below normal values. Activity of methionine adenosyltransferase was elevated throughout the period studied. The concentration of S-adenosylmethionine was likewise enhanced during hypertrophy. Administration of methylglyoxal bis(guanylhydrazone) produced a marked increase in adenosylmethionine decarboxylase activity and a large increase in putrescine concentration, but did not prevent the rise in spermidine concentration produced by denervation. Possible regulatory mechanisms of polyamine metabolism consistent with the observations are discussed.

THE ADRENAL CORTEX AND EFFECTS OF ADRENALINE ON CARBOHYDRATE METABOLISM IN THE ISOLATED RAT DIAPHRAGM

1963 ◽  
Vol 44 (1) ◽  
pp. 90-100
Author(s):  
P. R. Bouman ◽  
W. Dermer
Keyword(s):  
Glucose Uptake ◽  
Carbohydrate Metabolism ◽  
Glycogen Content ◽  
Qualitative Change ◽  
Glycogen Metabolism ◽  
Synergistic Action ◽  
Rat Diaphragm ◽  
Glycogen Deposition ◽  
Isolated Rat

ABSTRACT The in vitro effects of adrenaline on glycogen metabolism and glucose uptake were studied in diaphragms of intact, adrenalectomized and adrenodemedullated rats decapitated under »Nembutal« anaesthesia. Adrenalectomy and pretreatment of adrenalectomized rats with cortisol caused an increase in the net loss of glycogen induced by adrenaline. When glycogen deposition in the absence of adrenaline was also taken into account, the overall magnitude of the glycogenolytic response appeared to be unchanged. The apparent qualitative change in response induced by these procedures was attributed to increased initial glycogen values. In diaphragms of adrenalectomized and adrenodemedullated rats the response to adrenaline was identical, the initial glycogen content being the same in these preparations. None of the experimental procedures affected the variable inhibition of glucose uptake by adrenaline. These results do not favour the existence of a »permissive« or synergistic action of adrenocortical steroids with regard to the effects of adrenaline on peripheral carbohydrate metabolism.

EFFECTS OF ADRENALINE ON CARBOHYDRATE METABOLISM IN THE ISOLATED DIAPHRAGM OF INTACT AND ADRENALECTOMIZED RATS AS INFLUENCED BY »NEMBUTAL« ANAESTHESIA

1960 ◽  
Vol XXXV (IV) ◽  
pp. 541-550 ◽  
Author(s):  
P. R. Bouman ◽  
W. Dermer
Keyword(s):  
Glucose Uptake ◽  
Carbohydrate Metabolism ◽  
Glycogen Content ◽  
Glycogen Metabolism ◽  
Rat Diaphragm ◽  
Simultaneous Inhibition ◽  
Glycogen Deposition ◽  
Isolated Rat ◽  
Adrenalectomized Rats

ABSTRACT Hemidiaphragms of intact and adrenalectomized rats which had been killed by decapitation, were incubated for 1 hour at 37° C under aerobic conditions. Glucose uptake and glycogen deposition were determined. Addition of adrenaline in vitro (1 μg/ml) caused a substantial decrease in glucose uptake in both types of diaphragms, this decrease being equivalent to a simultaneous inhibition of glycogen deposition. »Nembutal« anaesthesia prior to decapitation was found to alter the response to adrenaline. This change was most clearly observed in diaphragms of adrenalectomized rats. Here, adrenaline mainly affected glycogen metabolism by way of glycogen degradation, whereas the overall magnitude of the response was not materially changed. However, glucose uptake appeared to be only slightly decreased by adrenaline under these conditions. The change in response to adrenaline was attributed to the higher initial glycogen content observed in diaphragms of nembutalized rats. It was suggested that prevention of an acute release of endogenous adrenergic substances, occurring after decapitation of unanaesthetized donor rats, may be the actual cause of this phenomenon. Attention was drawn to the significance of the initial glycogen content as an important factor in carbohydrate metabolism of the isolated rat diaphragm.

scholarly journals Dual-digitonin-pulse perfusion. Concurrent sampling of periportal and perivenous cytosol of rat liver for determination of metabolites and enzyme activities

1987 ◽  
Vol 243 (1) ◽  
pp. 87-95 ◽  
Author(s):  
B Quistorff ◽  
N Grunnet
Keyword(s):  
Lactate Dehydrogenase ◽  
Glutamine Synthetase ◽  
Rat Liver ◽  
High Purity ◽  
Alanine Aminotransferase ◽  
Specific Activity ◽  
Perfusion Technique ◽  
Short Intervals ◽  
Specific Activities

A previously described digitonin-perfusion technique [Quistorff, Grunnet & Cornell (1985) Biochem. J. 226, 289-297], by which intracellular material of rat liver could be liberated, has been refined, now allowing release of cytosol of high purity from both periportal and perivenous parts of the same liver. The cytosolic fractions are obtained by perfusing the liver for short intervals (10-20 s) with digitonin (4-5 mg/ml), first in the normal perfusion direction and then, after an interval of 1-2 min, in the retrograde direction, the eluate being collected during and after both intervals. The technique is termed ‘dual-digitonin-pulse perfusion’. The eluate fractions showed a peak specific activity of the cytosolic enzymes alanine aminotransferase (ALAT), lactate dehydrogenase (LDH) and pyruvate kinase (PK) of 3-5-fold higher than obtained in a biopsy from the same liver. For glutamine synthetase (GS) a 10-fold higher specific activity was obtained. Zonation, defined as the ratio of the specific activities in periportal and perivenous eluates, of ALAT, LDH and PK was 10, 1.7 and 0.70 respectively. Zonation of GS was less than 0.01. These factors may be modified by a slight zonation of cytosolic protein of 1.2-1.3. Peak concentrations in the eluate of ATP, ADP, Pi, NAD+ and glycerol 3-phosphate were 32.5 +/- 11.4, 19.9 +/- 4.3, 71.9 +/- 25.4, 2.41 +/- 0.83 and 6.84 +/- 2.74 nmol/mg of protein for periportal eluates. There was no difference between periportal and perivenous eluates except for glycerol 3-phosphate, which was significantly higher in perivenous eluates, 12.8 +/- 4.5 nmol/mg of protein.

Effects of crustacean hyperglycemic hormone (CHH) RNA interference on regulation of glucose metabolism in Litopenaeus vannamei after ammonia-N exposure

2021 ◽  
pp. 1-40
Author(s):  
Xin Zhang ◽  
Luqing Pan ◽  
Ruixue Tong ◽  
Yufen Li ◽  
Lingjun Si ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Litopenaeus Vannamei ◽  
Glycogen Phosphorylase ◽  
Glycogen Content ◽  
Glycogen Synthase ◽  
Glycogen Metabolism ◽  
Crustacean Hyperglycemic Hormone ◽  
Hyperglycemic Hormone ◽  
Rate Limiting ◽  
Creb Pathway

Abstract To unveil the adaptation of Litopenaeus vannamei to elevated ambient ammonia-N, crustacean hyperglycemic hormone (CHH) was knocked down to investigate its function in glucose metabolism pathway under ammonia-N exposure. When CHH was silenced, haemolymph glucose increased significantly during 3-6 h, decreased significantly during 12-48 h, and recovered to the control groups’ level at 72 h. After CHH knockdown, DA contents reduced significantly during 3-24 h, which recovered after 48 h. Besides, the expressions of GC and DA1R in the hepatopancreas decreased significantly, while DA4R increased significantly. Correspondingly, the contents of cAMP, cGMP and DAG and the expressions of PKA, PKG, AMPKα and AMPKγ were significantly downregulated, while the levels of PKC and AMPKβ were significantly upregulated. The expressions of CREB and GLUT2 decreased significantly, while GLUT1 increased significantly. Moreover, glycogen content, glycogen synthase and glycogen phosphorylase activities in hepatopancreas and muscle were significantly increased. Furthermore, the levels of key enzymes HK, PK and PFK in glycolysis, rate-limiting enzymes CS in TCA, and critical enzymes PEPCK, FBP and G6P in gluconeogenesis were significantly decreased in hepatopancreas. These results suggest that CHH affects DA, and then they affect their receptors respectively to transmit glucose metabolism signals into the hepatopancreas of L. vannamei under ammonia-N stress. CHH acts on cGMP-PKG-AMPKα-CREB pathway through GC, and CHH affects DA to influence cAMP-PKA-AMPKγ-CREB and DAG-PKC-AMPKβ-CREB pathways, thereby regulating GLUTs, inhibiting glycogen metabolism and promoting glycolysis and gluconeogenesis. This study contributes to further understand glucose metabolism mechanism of crustacean in response to environmental stress.

Glycogen metabolism in perfused contracting whole rat diaphragm muscle

1970 ◽  
Vol 219 (5) ◽  
pp. 1434-1439 ◽  
Author(s):  
GW Wermers ◽  
HM Cavert ◽  
JO Harris ◽  
CF Quello
Keyword(s):  
Glycogen Metabolism ◽  
Diaphragm Muscle ◽  
Rat Diaphragm

scholarly journals The effects of food deprivation and re-feeding on bovine adipose-tissue glycogen synthase

1979 ◽  
Vol 184 (2) ◽  
pp. 229-232 ◽  
Author(s):  
R D Eichner ◽  
R J Arnold
Keyword(s):  
Adipose Tissue ◽  
Phosphatase Activity ◽  
Food Deprivation ◽  
Glycogen Content ◽  
Specific Activity ◽  
Glycogen Synthase ◽  
Glycogen Metabolism ◽  
Phosphoprotein Phosphatase ◽  
Tissue Extracts ◽  
Rat Adipose Tissue

Bovine adipose-tissue glycogen metabolism was studied during food deprivation and re-feeding. Changes in the specific activity of adipose-tissue glycogen synthase paralleled changes in tissue glycogen content: both parameters increased during food deprivation and remained so during the first 10 days of re-feeding. The values for the A0.5 (activation constant) for glucose 6-phosphate of the freshly isolated enzyme from adipose tissue from fed and starved steers were 2.9 +/- 0.1 mM and 0.90 +/- 0.05 mM respectively. Additionally, whereas incubation of adipose-tissue extracts from fed steers did not activate endogenous glycogen synthase (through a presumed phosphoprotein phosphatase mechanism), the enzyme from starved or re-fed (up to 3 days re-feeding) steers was reversibly activated as measured by changes in the value for the A0.5 for glucose 6-phosphate. Thus activation of bovine adipose-tissue glycogen synthase during food deprivation appears to be related to expression of glycogen synthase phosphatase activity. These effects of food deprivation on bovine glycogen metabolism contrast markedly with the effects observed in rat adipose tissue.

scholarly journals Glycogen phosphorylase in glycogen-rich cells is involved in the energy supply for ion regulation in fish gill epithelia

2007 ◽  
Vol 293 (1) ◽  
pp. R482-R491 ◽  
Author(s):  
Yung-Che Tseng ◽  
Chang-Jen Huang ◽  
Joshua Chia-Hsi Chang ◽  
Wen-Yuan Teng ◽  
Otto Baba ◽  
...  
Keyword(s):  
Glycogen Phosphorylase ◽  
Glycogen Content ◽  
Glycogen Metabolism ◽  
Total Activity ◽  
Cellular Mechanisms ◽  
Ion Regulation ◽  
Energy Stores ◽  
Energy Dependent ◽  
Apical Opening

The molecular and cellular mechanisms behind glycogen metabolism and the energy metabolite translocation between mammal neurons and astrocytes have been well studied. A similar mechanism is proposed for rapid mobilization of local energy stores to support energy-dependent transepithelial ion transport in gills of the Mozambique tilapia ( Oreochromis mossambicus). A novel gill glycogen phosphorylase isoform (tGPGG), which catalyzes the initial degradation of glycogen, was identified in branchial epithelial cells of O. mossambicus. Double in situ hybridization and immunocytochemistry demonstrated that tGPGG mRNA and glycogen were colocalized in glycogen-rich cells (GRCs), which surround ionocytes (labeled with a Na+-K+-ATPase antiserum) in gill epithelia. Concanavalin-A (a marker for the apical membrane) labeling indicated that GRCs and mitochondria-rich cells share the same apical opening. Quantitative real-time PCR analyses showed that tGPGG mRNA expression levels specifically responded to environmental salinity changes. Indeed, the glycogen content, glycogen phosphorylase (GP) protein level and total activity, and the density of tGPGG-expressing cells (i.e., GRCs) in fish acclimated to seawater (SW) were significantly higher than those in freshwater controls. Short-term acclimation to SW caused an evident depletion in the glycogen content of GRCs. Taken altogether, tGPGG expression in GRCs is stimulated by hyperosmotic challenge, and this may catalyze initial glycogen degradation to provide the adjacent ionocytes with energy to carry out iono- and osmoregulatory functions.

Role of glucocorticoid in the regulation of glycogen metabolism in skeletal muscle

1991 ◽  
Vol 260 (6) ◽  
pp. E927-E932 ◽  
Author(s):  
L. Coderre ◽  
A. K. Srivastava ◽  
J. L. Chiasson
Keyword(s):  
Skeletal Muscle ◽  
Muscle Contraction ◽  
Glycogen Phosphorylase ◽  
Glycogen Content ◽  
Glycogen Synthase ◽  
Glycogen Metabolism ◽  
Activity Ratios ◽  
Resting Muscle ◽  
Glycogen Breakdown

With the use of the hindlimb perfusion technique, the effect of glucocorticoid on the regulation of glycogen metabolism was studied in rat skeletal muscle. Rats were adrenalectomized (ADX) or sham operated (controls) 14 days before the study. The ADX animals were treated with either saline or corticosterone, and the hindlimbs were perfused at rest or during muscle contraction with saline or epinephrine (10(-7) M). In the resting state, the glycogen content was 33.0 +/- 1.9 mumol/g in the controls, and the activity ratios of glycogen phosphorylase (GPase) and glycogen synthase (GSase) were 0.27 +/- 0.03 and 0.15 +/- 0.02, respectively. Epinephrine treatment increased GPase activity (0.78 +/- 0.03) and decreased GSase activity (0.05 +/- 0.01), which resulted in decreased glycogen content (25.7 +/- 0.9 mumol/g; P less than 0.01). Adrenalectomy induced a 35% reduction in glycogen content but had no effect on the activities of basal enzymes. Under these conditions, however, epinephrine had no effect on GPase activity, had a diminished effect on GSase activity (0.11 +/- 0.01), and did not induce further glycogen breakdown. Corticosterone replacement normalized muscle glycogen content in ADX rats as well as the response of the enzymes to epinephrine. Muscle contraction resulted in a decrease in glycogen content (8.9 +/- 1.3 mumol/g) and in GPase activity (0.14 +/- 0.02) and an increase in GSase activity (0.25 +/- 0.01); this was not affected by adrenalectomy nor by epinephrine. In conclusion, these data indicate that glucocorticoid is essential for the effects of epinephrine on GPase activation. on GSase inhibition, and consequently on glycogen breakdown in resting muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

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