Evidence for the coupling of the regulations of tyrosine aminotransferase and phosphoenolpyruvate carboxykinase

1970 ◽  
Vol 48 (12) ◽  
pp. 1297-1301 ◽  
Author(s):  
E. A. Lane ◽  
C. Mavrides
Keyword(s):  
Experimental Design ◽  
Dietary Protein ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Glycogen Content ◽  
Quantitative Relationship ◽  
Liver Glycogen ◽  
Tyrosine Aminotransferase ◽  
Liver Glycogen Content ◽  
Light Darkness ◽  
Similar Rhythm

An experimental design which simulated a light–darkness schedule reproduced the daily rhythm of tyrosine aminotransferase in rat liver. A similar rhythm was identified for phosphoenolpyruvate carboxykinase. Both enzyme rhythms were profoundly and similarly modified by the amount of dietary protein fed to the animals. The liver glycogen content fluctuated in a manner that produced plots which were virtually the mirror images of the enzyme rhythm plots. The oscillations of phosphoenolpyruvate carboxykinase were less pronounced than those of tyrosine aminotransferase and the same quantitative relationship was found in response to infused nonpharmacological amounts of Cortisol.A relationship in the regulations of the two enzymes suggested by the present and other experiments is envisaged and discussed.

Differences in glycogen, lipids, and enzymes in livers from rats flown on COSMOS 2044

1992 ◽  
Vol 73 (2) ◽  
pp. S142-S147 ◽  
Author(s):  
A. H. Merrill ◽  
E. Wang ◽  
R. LaRocque ◽  
R. E. Mullins ◽  
E. T. Morgan ◽  
...  
Keyword(s):  
Liver Function ◽  
Glycogen Content ◽  
Aminolevulinic Acid ◽  
Recovery Period ◽  
Liver Glycogen ◽  
Microsomal Protein ◽  
Tyrosine Aminotransferase ◽  
Synchronous Control ◽  
Liver Glycogen Content ◽  
Rate Limiting

Livers from rats flown aboard COSMOS 2044 were analyzed for protein, carbohydrate (glycogen), and lipids as well as the activities of a number of key enzymes involved in metabolism of these compounds and xenobiotics. The major differences between the flight group and the synchronous control were elevations in microsomal protein, liver glycogen content, tyrosine aminotransferase, and tryptophan oxygenase and reductions in sphingolipids and the rate-limiting enzyme of heme biosynthesis, delta-aminolevulinic acid synthase. These results provide further evidence that spaceflight has pronounced and diverse effects on liver function; however, some of the results with samples from COSMOS 2044 differed notably from those from previous spaceflights. This may be due to conditions of spaceflight and/or the postflight recovery period for COSMOS 2044.

Interleukin-6 secretion in mice is associated with reduced glucose-6-phosphatase and liver glycogen levels

1997 ◽  
Vol 273 (2) ◽  
pp. E262-E267 ◽  
Author(s):  
S. Metzger ◽  
N. Goldschmidt ◽  
V. Barash ◽  
T. Peretz ◽  
O. Drize ◽  
...  
Keyword(s):  
Interleukin 6 ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Glycogen Content ◽  
Liver Glycogen ◽  
Mrna Levels ◽  
Chronic Effect ◽  
Glucose Levels ◽  
Reduced Body ◽  
Blood Glucose Levels ◽  
Liver Glycogen Content

Mice bearing interleukin-6 (IL-6)-secreting tumor were used to study the chronic effect of IL-6 on carbohydrate metabolism. Mice were injected with allogeneic tumor cells transduced with the murine IL-6 gene. Serum IL-6 levels were correlated exponentially with tumor weight. Secretion of IL-6 from the developed tumors was associated with decreased food consumption, reduced body weight, and reduced blood glucose levels. Insulin levels did not change, and 2-deoxyglucose uptake was not affected in most tissues examined. A significant increase of 2-deoxyglucose uptake was measured in the liver. Glycogen content in the liver determined 0, 6, 12, and 18 days after tumor inoculation was 42, 23, 12, and 3 mg/g, respectively. The activity of phosphoenolpyruvate carboxykinase was not affected. The activity of glucose-6-phosphatase (G-6-Phase) determined 6, 12, and 18 days after tumor injection was 84, 70, and 50% of G-6-Pase activity in pair-fed mice bearing nonsecreting tumors, respectively. G-6-Pase mRNA levels were markedly reduced due to inhibition of G-6-Pase gene transcriptional rate.

Hypothalamic HSP10 Impacts Mitochondrial Dynamics, Insulin Signaling, and Liver Glycogen Content

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 1801-P
Author(s):  
KRISTINA WARDELMANN ◽  
JOSÉ PEDRO CASTRO ◽  
MICHAELA RATH ◽  
JÜRGEN WEIß ◽  
ANNETTE SCHUERMANN ◽  
...  
Keyword(s):  
Insulin Signaling ◽  
Glycogen Content ◽  
Mitochondrial Dynamics ◽  
Liver Glycogen ◽  
Liver Glycogen Content

BIOCHEMICAL STUDIES ON SOCKEYE SALMON DURING SPAWNING MIGRATION: XII. LIVER GLYCOGEN

1960 ◽  
Vol 38 (1) ◽  
pp. 553-558 ◽  
Author(s):  
Violet M. Chang ◽  
D. R. Idler
Keyword(s):  
Sex Differences ◽  
Sockeye Salmon ◽  
Glycogen Content ◽  
Steroid Hormone ◽  
Liver Glycogen ◽  
Spawning Migration ◽  
Energy Expenditures ◽  
Liver Glycogen Content ◽  
Biochemical Studies ◽  
River Migration

Liver glycogen levels were determined for a pure stock of sockeye salmon (Oncorhynchus nerka) taken at three locations during spawning migration. The liver glycogen content of the male was found to be consistently greater than that of the female throughout the entire river migration. In both sexes liver glycogen decreased during the earlier phase of migration, but increased during the later stage so that the levels at the spawning grounds were approximately twice those at the mouth of the river. The changes which occur are discussed in relation to sex differences, energy expenditures, and plasma steroid hormone levels.

Liver glycogen-induced enhancements in hypoglycemic counterregulation require neuroglucopenia.

2021 ◽  
Author(s):  
Shana O Warner ◽  
Abby M Wadian ◽  
Marta S. Smith ◽  
Ben Farmer ◽  
Yufei Dai ◽  
...  
Keyword(s):  
Glycogen Content ◽  
Hormone Secretion ◽  
Control Period ◽  
Liver Glycogen ◽  
Saline Infusion ◽  
Glucose Levels ◽  
Liver Glycogen Content ◽  
Patients With Diabetes ◽  
Arterial Plasma ◽  
The Brain

Iatrogenic hypoglycemia is a prominent barrier to achieving optimal glycemic control in patients with diabetes, in part due to dampened counterregulatory hormone responses. It has been demonstrated that elevated liver glycogen content can enhance these hormonal responses through signaling to the brain via afferent nerves, but the role that hypoglycemia in the brain plays in this liver glycogen effect remains unclear. During the first 4hrs of each study, the liver glycogen content of dogs was increased by using an intraportal infusion of fructose to stimulate hepatic glucose uptake (HG; n=13), or glycogen was maintained near fasting levels with a saline infusion (NG; n=6). After a 2hr control period, during which the fructose/saline infusion was discontinued, insulin was infused intravenously for an additional 2hrs to bring about systemic hypoglycemia in all animals, whereas brain euglycemia was maintained in a subset of the HG group by infusing glucose bilaterally into the carotid and vertebral arteries (HG-HeadEu; n=7). Liver glycogen content was markedly elevated in the two HG groups (43±4, 73±3 and 75±7 mg/g in NG, HG and HG-HeadEu, respectively). During the hypoglycemic period, arterial plasma glucose levels were indistinguishable between groups (53±2, 52±1 and 51±1 mg/dL, respectively), but jugular vein glucose levels were kept euglycemic (88±5 mg/dL) only in the HG-HeadEu group. Glucagon and epinephrine responses to hypoglycemia were higher in HG compared to NG, whereas despite the increase in liver glycogen, neither increased above basal in HG-HeadEu. These data demonstrate that the enhanced counterregulatory hormone secretion that accompanies increased liver glycogen content requires hypoglycemia in the brain.

Influence de la thiourée sur la charge en glycogéne du foie de l'embryon de poulet

Development ◽  
1971 ◽  
Vol 25 (3) ◽  
pp. 377-384
Author(s):  
Nicole Daugéras
Keyword(s):  
Chick Embryo ◽  
Glycogen Content ◽  
Antithyroid Drug ◽  
Liver Glycogen ◽  
Thyroid Activity ◽  
Glycogen Level ◽  
Glycogen Concentration ◽  
Liver Glycogen Content ◽  
Thyroid Glands ◽  
Embryo Liver

Influence of thiourea on the glycogen content of the liver of the chick embryo In the developing chick embryo, liver glycogen appears on the sixth day of incubation. The glycogen content increases from the sixth day, but decreases on the twelfth day before increasing again. This decrease on day 12 might be related to the onset of thyroid activity, which would be responsible for an increased rate of utilization of the substrates. An antithyroid drug, thiourea, has been injected on day 6·0. The liver glycogen concentration of the thiourea-treated chick embryos was determined from the tenth to the fifteenth days and compared with that of the control embryos. (i) On days 11 and 12 the liver glycogen concentration of the injected embryos is higher than that of the controls. (ii) On day 13 the liver glycogen level of treated embryos decreases; this decrease might be correlated with possible functional activity of the thyroid glands if their biosynthesis is no longer inhibited by the thiourea injection or with thyroid hormones possibly coming from the yolk. (iii) On days 14 and 15 no difference is observed between the liver glycogen content of the thiourea-treated embryos and that of the controls.

Adrenodemedullation affects endurance but not hepatic fructose 2,6-bisphosphate

1988 ◽  
Vol 254 (4) ◽  
pp. R572-R577 ◽  
Author(s):  
H. T. Yang ◽  
R. L. Hammer ◽  
T. L. Sellers ◽  
J. Arogyasami ◽  
D. T. Carrell ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Adrenal Medulla ◽  
Endurance Exercise ◽  
Glycogen Content ◽  
Vastus Lateralis ◽  
Liver Glycogen ◽  
Glycogen Depletion ◽  
Epinephrine Infusion ◽  
Liver Glycogen Content

Sham-operated (SHAM) and saline (ADM-S)- or epinephrine (ADM-E)-infused adrenodemedullated rats were run on a treadmill (21 m/min, 15% grade) for 80 min or until exhaustion. ADM-S rats had significantly lower endurance run times (116 +/- 6 min) than ADM-E rats (136 +/- 8 min) and SHAM rats (150 +/- 6 min). Liver glycogen content dropped from 56 +/- 4 to 10 +/- 2 mg/g in SHAM and from 54 +/- 4 to 18 +/- 5 mg/g in ADM-S and to 20 +/- 8 mg/g in ADM-E rats at 80 min. Liver glycogen was depleted in all rats at exhaustion. Liver fructose 2,6-bisphosphate was decreased markedly in exercising rats, and the extent of decrease was not influenced by adrenodemedullation or by epinephrine infusion. ADM-S rats showed impaired glycogen depletion in the white vastus lateralis and soleus muscles, hypoglycemia, and low blood lactate at 80 min and at exhaustion. Infusion of epinephrine into ADM rats reversed these deficiencies. These data indicate that the adrenal medulla is unessential for normal endurance exercise as long as liver glycogen is available. After liver glycogen is depleted, epinephrine from the adrenal medulla prevents hypoglycemia and is essential for allowing continuation of exercise.

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