Liver glycogen content decreases during meals in rats

1982 ◽  
Vol 243 (3) ◽  
pp. R450-R453
Author(s):  
W. Langhans ◽  
N. Geary ◽  
E. Scharrer
Keyword(s):  
Blood Glucose ◽  
Glycogen Content ◽  
Liver Glycogen ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Liver Glycogen Content ◽  
Ad Libitum ◽  
Portal Veins ◽  
Hepatic Portal

The effects of feeding on liver glycogen content and blood glucose in the hepatic and hepatic portal veins were investigated in rats. Liver glycogen content decreased about 25% during meals both in rats refed after 12 h food deprivation (23 +/- 1 to 17 +/- 1 mg glycogen/g liver) and in ad libitum-fed rats taking fully spontaneous meals (44 +/- 2 to 32 +/- 2 mg/g). Liver glycogen began to increase within 30 min after meals in ad libitum-fed rats. Hepatic vein blood glucose levels at meal onset (118 +/- 4 mg/dl in the food-deprived rats, 127 +/- 4 in ad libitum-fed rats) and at meal end (155 +/- 3 and 166 +/- 5 mg/dl, respectively) were similar in the two groups. Portal vein blood glucose increased during meals in the previously food-deprived rats (83 +/- 4 to 116 +/- 6 mg/dl) but not in the ad libitum-fed rats (127 +/- 5 to 132 +/- 3 mg/dl). Mechanisms that may elicit prandial glycogenolysis and the possible role of this effect in the production of meal ending satiety are discussed.

Metabolic concomitants of glucagon-induced suppression of feeding in the rat

1981 ◽  
Vol 241 (5) ◽  
pp. R330-R335 ◽  
Author(s):  
N. Geary ◽  
W. Langhans ◽  
E. Scharrer
Keyword(s):  
Blood Glucose ◽  
Glycogen Content ◽  
Behavioral Effect ◽  
Liver Glycogen ◽  
Nonesterified Fatty Acid ◽  
Dark Phase ◽  
Light Phase ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Liver Glycogen Content

The suppression of food intake elicited in rats by injection of pancreatic glucagon and the accompanying changes in energy metabolite flux were investigated. Glucagon injections, 120-360 micrograms ip, were made as rats began the first meal of the dark phase after food deprivation during the light phase. Glucagon-injected rats terminated their meals sooner and ate smaller meals than vehicle-injected rats. For metabolic assays, rats were identically treated and killed just at meal onset or 15 min later. Portal vein blood glucose increased similarly in all rats allowed to feed, whereas plasma nonesterified fatty acid and D-(-)-3-hydroxybutyrate levels decreased during feeding. In contrast, hepatic vein and aorta blood glucose levels increased more after glucagon than after vehicle injections. Liver glycogen content decreased after glucagon injections. The highest glucagon dose only had slight lipolytic and ketogenic effects. It was concluded the glycogenolytic and hyperglycemic action of glucagon may generate a satiety signal sufficient to cause premature termination of meals. Changes in ketone and lipid fluxes do not appear necessary for this behavioral effect.

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.

Carbohydrate metabolism of mice exposed to simulated changes in gravity

1964 ◽  
Vol 207 (2) ◽  
pp. 411-414 ◽  
Author(s):  
Jiro Oyama ◽  
William T. Platt
Keyword(s):  
Blood Glucose ◽  
Carbohydrate Metabolism ◽  
Exposure Time ◽  
Liver Glycogen ◽  
Critical Function ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Significant Difference ◽  
Glycogen Deposition ◽  
Adrenal Corticosterone

Unrestrained mice were centrifuged for varying periods ranging from 0.5 to 10 hr at 2.5, 5, and 10 x gravity. Liver glycogen and blood glucose levels increased significantly depending on the g load and exposure time. Adrenalectomy completely abolished the glycogen deposition response. The glycogen response was a critical function of the age of mice; unweaned mice did not respond. Blood corticosterone increased significantly prior to the deposition of glycogen. Centrifuged fed mice deposited three times the amount of glycogen of fasted mice. There was no significant difference in the amount of glycogen deposited in centrifuged mice previously starved for 1, 2, or 3 days. It is concluded that the increased glycogen deposited following centrifugation is effected by an increased elaboration of adrenal corticosterone.

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.

VARIATIONS IN GLUCAGON RESPONSE AMONG JUVENILE DIABETICS

PEDIATRICS ◽  
1963 ◽  
Vol 32 (6) ◽  
pp. 1002-1006
Author(s):  
Donnell D. Etzwiler
Keyword(s):  
Blood Glucose ◽  
Good Control ◽  
Liver Glycogen ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Juvenile Diabetics ◽  
Glycogen Stores ◽  
Initial Blood ◽  
Hyperglycemic Effect

Glucagon or a placebo preparation was administered to 65 juvenile diabetics on 74 separate occasions. When the initial blood glucose of these children showed them to be in reasonably good control, glucagon produced a hyperglycemic effect. However, when the blood glucose levels were markedly elevated, the effect of glucagon was less predictable. The depletion of liver glycogen stores and the possible effect of contaminating insulin in glucagon preparations are discussed.

Effect of Corn Oil on Liver Glycogen Content and Blood Glucose-6-phosphatase Dehydrogenase in Toads Treated with DMBA

1999 ◽  
Vol 3 (1) ◽  
pp. 31-34
Author(s):  
N.E. Abdelmeguid . ◽  
I. A. Sadek . ◽  
J. M. Sorour . ◽  
A. A. Attia .
Keyword(s):  
Blood Glucose ◽  
Glycogen Content ◽  
Corn Oil ◽  
Liver Glycogen ◽  
Liver Glycogen Content

Endurance training attenuates stress hormone responses to exercise in fasted rats

1982 ◽  
Vol 243 (1) ◽  
pp. R179-R184 ◽  
Author(s):  
W. W. Winder ◽  
M. A. Beattie ◽  
R. T. Holman
Keyword(s):  
Blood Glucose ◽  
Plasma Concentrations ◽  
Liver Glycogen ◽  
Stress Hormone ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Fasted State ◽  
Hormone Responses ◽  
Exercise Muscle ◽  
Fasted Rats

Endurance exercise training produces major adaptations in hormonal and metabolic responses to exercise. This study was designed to determine whether the differences in hormone response persist in the fasted condition when liver glycogen is depleted. Rats were run on a motor-driven rodent treadmill 5 days/wk for periods up to 2 h/day for 10 wk. Trained and nontrained rats were then fasted 24 h and were run for periods ranging from 0- to 60 min. At the end of 60 min of exercise muscle glycogen was higher in trained rats (2.9 +/- 0.3 vs. 1.1 +/- 0.1 mg/g). Blood glucose was maintained at higher levels in trained rats throughout the course of the exercise (3.2 +/- 0.1 vs. 2.3 +/- 0.1 mM after 60 min). Plasma concentrations of glucagon and epinephrine increased in both groups during the exercise but were significantly lower in trained animals. Differences between trained and nontrained animals in stress hormone responses to exercise persist in the fasted state and appear to be a consequence of the capacity of trained animals to maintain higher blood glucose levels.

The Role of Biomaterials in Insulin Delivery Systems

1980 ◽  
Vol 3 (5) ◽  
pp. 299-304 ◽  
Author(s):  
S.D. Bruck
Keyword(s):  
Blood Glucose ◽  
Glucose Sensor ◽  
Insulin Delivery ◽  
The United States ◽  
Delivery Systems ◽  
Open Loop ◽  
Health Concern ◽  
Glucose Levels ◽  
Blood Glucose Levels

The control of blood glucose levels in diabetes involving devices are critically reviewed, and the role of blood-contacting biomaterial components analyzed. These include mechanical insulin-delivery systems of the closed-loop type that require an electronic glucose sensor and feedback, and open-loop systems that deliver insulin without a sensor and feedback. Whole pancreatic and islet transplantations, islet encapsulation, and the potential role of polymeric sustained drug delivery systems are discussed. The medical and social impacts of diabetes mellitus are of prime public health concern and of even greater magnitude than those of heart disease in the United States. While future advances in device design, miniaturization, and biometrials technology will significantly add to the arsenal of therapeutic alternatives, devices capable of controlling blood glucose levels ought to be viewed as mere interim phases rather than as final goals of the problem.

Selected Contribution: Evidence that the decrease in liver glycogen is associated with the exercise-induced increase in IGFBP-1

2002 ◽  
Vol 93 (2) ◽  
pp. 798-804 ◽  
Author(s):  
Jean-Marc Lavoie ◽  
Yovan Fillion ◽  
Karine Couturier ◽  
Pierre Corriveau
Keyword(s):  
Blood Glucose ◽  
Glycogen Content ◽  
Liver Glycogen ◽  
Lower Blood Glucose ◽  
Insulin Levels ◽  
Liver Glycogen Content ◽  
Lower Blood ◽  
Lipid Response ◽  
Exercise Induced ◽  
Fasted Rats

The purpose of the present study was to test the hypothesis that the exercise-induced increase in insulin-like growth factor binding protein (IGFBP)-1 is not always linked to a decrease in blood glucose level and to examine whether the decreasing levels of liver glycogen during exercise may be associated with the increase in IGFBP-1. Three groups of rats were submitted to a 70-min treadmill exercise. One group of rats was fed normally, and the two other groups had their food intake restricted by 50% (50% fast) the night before the experiment. One of these two 50% fasted groups of rats was infused (intravenously) with glucose throughout exercise to maintain euglycemia. Exercise in noninfused 50% fasted rats, compared with the normally fed rats, resulted in significantly lower blood glucose ( minute 70) and insulin levels, significantly lower liver glycogen content, no change in IGF-I, and significantly higher increases in free fatty acid, glycerol, β-hydroxybutyrate, and IGFBP-1. Maintenance of euglycemia during exercise in glucose-infused 50% fasted rats reduced to a large extent the decrease in insulin levels but only slightly attenuated the lipid response and the IGFBP-1 response seen in noninfused 50% fasted rats. Comparisons of all individual liver glycogen and IGFBP-1 values revealed that liver glycogen values were highly ( P < 0.001) predictive of the IGFBP-1 response during exercise ( R = 0.564). The present results indicate that the IGFBP-1 response during exercise is not always linked to a decrease in plasma glucose and suggest that the increase in IGFBP-1 during exercise may be related to the decrease in liver glycogen content.

Sign in / Sign up

Export Citation Format

Share Document