Effect of indomethacin on hepatic glucose production in vitro: The impact of hepatic glycogen content

Life Sciences ◽  
1985 ◽  
Vol 37 (19) ◽  
pp. 1829-1833 ◽  
Author(s):  
Martin Komjati ◽  
Heinrich Vierhapper ◽  
Werner Waldhäusl
Keyword(s):  
Glycogen Content ◽  
Hepatic Glucose Production ◽  
Glucose Production ◽  
Hepatic Glycogen ◽  
Hepatic Glucose ◽  
The Impact

scholarly journals Autoregulation of hepatic glucose production

1998 ◽  
pp. 240-248 ◽  
Author(s):  
MC Moore ◽  
CC Connolly ◽  
AD Cherrington
Keyword(s):  
Hepatic Glucose Production ◽  
Glucose Production ◽  
Hepatic Glycogen ◽  
Neural Pathways ◽  
Hepatic Glucose Output ◽  
Counterregulatory Hormones ◽  
Hepatic Glucose ◽  
Glucose Output

In vitro evidence indicates that the liver responds directly to changes in circulating glucose concentrations with reciprocal changes in glucose production and that this autoregulation plays a role in maintenance of normoglycemia. Under in vivo conditions it is difficult to separate the effects of glucose on neural regulation mediated by the central nervous system from its direct effect on the liver. Nevertheless, it is clear that nonhormonal mechanisms can cause significant changes in net hepatic glucose balance. In response to hyperglycemia, net hepatic glucose output can be decreased by as much as 60-90% by nonhormonal mechanisms. Under conditions in which hepatic glycogen stores are high (i.e. the overnight-fasted state), a decrease in the glycogenolytic rate and an increase in the rate of glucose cycling within the liver appear to be the explanation for the decrease in hepatic glucose output seen in response to hyperglycemia. During more prolonged fasting, when glycogen levels are reduced, a decrease in gluconeogenesis may occur as a part of the nonhormonal response to hyperglycemia. A substantial role for hepatic autoregulation in the response to insulin-induced hypoglycemia is most clearly evident in severe hypoglycemia (< or = 2.8 mmol/l). The nonhormonal response to hypoglycemia apparently involves enhancement of both gluconeogenesis and glycogenolysis and is capable of supplying enough glucose to meet at least half of the requirement of the brain. The nonhormonal response can include neural signaling, as well as autoregulation. However, even in the absence of the ability to secrete counterregulatory hormones (glucocorticoids, catecholamines, and glucagon), dogs with denervated livers (to interrupt neural pathways between the liver and brain) were able to respond to hypoglycemia with increases in net hepatic glucose output. Thus, even though the endocrine system provides the primary response to changes in glycemia, autoregulation plays an important adjunctive role.

Influence of prior exercise and liver glycogen content on the sensitivity of the liver to glucagon

2002 ◽  
Vol 92 (1) ◽  
pp. 188-194 ◽  
Author(s):  
Victoria Matas Bonjorn ◽  
Martin G. Latour ◽  
Patrice Bélanger ◽  
Jean-Marc Lavoie
Keyword(s):  
Glucose Utilization ◽  
Glycogen Content ◽  
Hepatic Glucose Production ◽  
Glucose Production ◽  
Liver Glycogen ◽  
Hepatic Glycogen ◽  
Prior Exercise ◽  
Hepatic Glucose ◽  
Increased Sensitivity ◽  
Glucagon And Insulin

The purpose of the present study was to test the hypothesis that a prior period of exercise is associated with an increase in hepatic glucagon sensitivity. Hepatic glucose production (HGP) was measured in four groups of anesthetized rats infused with glucagon (2 μg · kg−1 · min−1 iv) over a period of 60 min. Among these groups, two were normally fed and, therefore, had a normal level of liver glycogen (NG). One of these two groups was killed at rest (NG-Re) and the other after a period of exercise (NG-Ex; 60 min of running, 15–26 m/min, 0% grade). The two other groups of rats had a high hepatic glycogen level (HG), which had been increased by a fast-refed diet, and were also killed either at rest (HG-Re) or after exercise (HG-Ex). Plasma glucagon and insulin levels were increased similarly in all four conditions. Glucagon-induced hyperglycemia was higher ( P < 0.01) in the HG-Re group than in all other groups. HGP in the HG-Re group was not, however, on the whole more elevated than in the NG-Re group. Exercised rats (NG-Ex and HG-Ex) had higher hyperglycemia, HGP, and glucose utilization than rested rats in the first 10 min of the glucagon infusion. HG-Ex group had the highest HGP throughout the 60-min experiment. It is concluded that hyperglucagonemia-induced HGP is stimulated by a prior period of exercise, suggesting an increased sensitivity of the liver to glucagon during exercise.

Effect of liver glycogen content on glucose production in running rats

1989 ◽  
Vol 66 (1) ◽  
pp. 318-322 ◽  
Author(s):  
J. Vissing ◽  
J. L. Wallace ◽  
H. Galbo
Keyword(s):  
Plasma Glucose ◽  
Glycogen Content ◽  
Hepatic Glucose Production ◽  
Plasma Concentrations ◽  
Glucose Production ◽  
Liver Glycogen ◽  
Treadmill Running ◽  
Hepatic Glycogen ◽  
Hepatic Glucose ◽  
Exercise Induced

The influence of supranormal compared with normal hepatic glycogen levels on hepatic glucose production (Ra) during exercise was investigated in chronically catheterized rats. Supranormal hepatic glycogen levels were obtained by a 24-h fast-24-h refeeding regimen. During treadmill running for 35 min at a speed of 21 m/min, Ra and plasma glucose increased more (P less than 0.05) and liver glucogen breakdown was larger in fasted-refed compared with control rats, although the stimuli for Ra were higher in control rats, the plasma concentrations of insulin and glucose being lower (P less than 0.05) in control compared with fasted-refed rats. Also, plasma concentrations of glucagon and both catecholamines tended to be higher and muscle glycogenolysis lower in control compared with fasted-refed rats. Lipid metabolism was similar in the two groups. The results indicate that hepatic glycogenolysis during exercise is directly related to hepatic glycogen content. The smaller endocrine glycogenolytic signal in face of higher plasma glucose concentrations in fasted-refed compared with control rats is indicative of metabolic feedback control of glucose mobilization during exercise. However, the higher exercise-induced increase in Ra, plasma glucose, and liver glycogen breakdown in fasted-refed compared with control rats indicates that metabolic feedback mechanisms are not able to accurately match Ra to the metabolic needs of working muscles.

scholarly journals The impact of obesity, sex, and diet on hepatic glucose production in cats

2009 ◽  
Vol 296 (4) ◽  
pp. R936-R943 ◽  
Author(s):  
Saskia Kley ◽  
Margarethe Hoenig ◽  
John Glushka ◽  
Eunsook S. Jin ◽  
Shawn C. Burgess ◽  
...  
Keyword(s):  
Phosphoenolpyruvate Carboxykinase ◽  
Citrate Synthase ◽  
Hepatic Glucose Production ◽  
Glucose Production ◽  
Endogenous Glucose Production ◽  
Hepatic Glucose Metabolism ◽  
Peripheral Insulin Resistance ◽  
Pyruvate Cycling ◽  
Hepatic Glucose ◽  
The Impact

Obesity is a risk factor for type 2 diabetes in cats. The risk of developing diabetes is severalfold greater for male cats than for females, even after having been neutered early in life. The purpose of this study was to investigate the role of different metabolic pathways in the regulation of endogenous glucose production (EGP) during the fasted state considering these risk factors. A triple tracer protocol using 2H2O, [U-13C3]propionate, and [3,4-13C2]glucose was applied in overnight-fasted cats (12 lean and 12 obese; equal sex distribution) fed three different diets. Compared with lean cats, obese cats had higher insulin ( P < 0.001) but similar blood glucose concentrations. EGP was lower in obese cats ( P < 0.001) due to lower glycogenolysis and gluconeogenesis (GNG; P < 0.03). Insulin, body mass index, and girth correlated negatively with EGP ( P < 0.003). Female obese cats had ∼1.5 times higher fluxes through phosphoenolpyruvate carboxykinase ( P < 0.02) and citrate synthase ( P < 0.05) than male obese cats. However, GNG was not higher because pyruvate cycling was increased 1.5-fold ( P < 0.03). These results support the notion that fasted obese cats have lower hepatic EGP compared with lean cats and are still capable of maintaining fasting euglycemia, despite the well-documented existence of peripheral insulin resistance in obese cats. Our data further suggest that sex-related differences exist in the regulation of hepatic glucose metabolism in obese cats, suggesting that pyruvate cycling acts as a controlling mechanism to modulate EGP. Increased pyruvate cycling could therefore be an important factor in modulating the diabetes risk in female cats.

Contribution of net hepatic glycogenolysis to glucose production during the early postprandial period

1996 ◽  
Vol 270 (1) ◽  
pp. E186-E191 ◽  
Author(s):  
K. F. Petersen ◽  
T. Price ◽  
G. W. Cline ◽  
D. L. Rothman ◽  
G. I. Shulman
Keyword(s):  
Magnetic Resonance ◽  
Glycogen Content ◽  
Hepatic Glucose Production ◽  
Liver Volume ◽  
Glucose Production ◽  
Liver Glycogen ◽  
Whole Body ◽  
Hepatic Glycogen ◽  
Resonance Spectroscopy ◽  
13C Nuclear Magnetic Resonance

Relative contributions of net hepatic glycogenolysis and gluconeogenesis to glucose production during the first 12 h of a fast were studied in 13 healthy volunteers by noninvasively measuring hepatic glycogen content using 13C nuclear magnetic resonance spectroscopy. Rates of net hepatic glycogenolysis were calculated by multiplying the change in liver glycogen content with liver volume determined by magnetic resonance imaging. Rates of gluconeogenesis were calculated as the difference between rates of glucose production determined with an infusion of [6,6-2H]-glucose and net hepatic glycogenolysis. At 6 P.M. a liquid mixed meal (1,000 kcal; 60% as glucose) was given, to which [2-2H]glucose was added to trace glucose absorption. Hepatic glycogen content was measured between 11 P.M. and 1 A.M. and between 3 and 6 A.M. At 11 P.M. the concentration was 470 mM and it decreased linearly during the night. The mean liver volume was 1.47 +/- 0.06 liters. Net hepatic glycogenolysis (5.8 +/- 0.8 mumol.kg body wt-1.min-1) accounted for, on average, 45 +/- 6% and gluconeogenesis for 55 +/- 6% of the rate of whole body glucose production (12.6 +/- 0.6 mumol.kg body wt-1.min-1). In conclusion, this study shows that, even early in the phase of the postabsorptive period when liver glycogen stores are maximal, gluconeogenesis contributes approximately 50% to hepatic glucose production.

scholarly journals Control of gluconeogenic genes during intense/prolonged exercise: hormone-independent effect of muscle-derived IL-6 on hepatic tissue and PEPCK mRNA

2009 ◽  
Vol 107 (6) ◽  
pp. 1830-1839 ◽  
Author(s):  
Sébastien Banzet ◽  
Nathalie Koulmann ◽  
Nadine Simler ◽  
Hervé Sanchez ◽  
Rachel Chapot ◽  
...  
Keyword(s):  
Phosphoenolpyruvate Carboxykinase ◽  
Hepatic Glucose Production ◽  
Glucose Production ◽  
Independent Effect ◽  
Hepatic Tissue ◽  
Hepatic Glycogen ◽  
Mrna Levels ◽  
Hepatic Glucose ◽  
Responsive Gene ◽  
Gene Mrna

Prolonged intense exercise is challenging for the liver to maintain plasma glucose levels. Hormonal changes cannot fully account for exercise-induced hepatic glucose production (HGP). Contracting skeletal muscles release interleukin-6 (IL-6), a cytokine able to increase endogenous glucose production during exercise. However, whether this is attributable to a direct effect of IL-6 on liver remains unknown. Here, we studied hepatic glycogen, gluconeogenic genes, and IL-6 signaling in response to one bout of exhaustive running exercise in rats. To determine whether IL-6 can modulate gluconeogenic gene mRNA independently of exercise, we injected resting rats with recombinant IL-6. Exhaustive exercise resulted in a profound decrease in liver glycogen and an increase in gluconeogenic gene mRNA levels, phosphoenolpyruvate-carboxykinase (PEPCK), glucose-6-phosphatase (G6P), and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), suggesting a key role for gluconeogenesis in hepatic glucose production. This was associated to an active IL-6 signaling in liver tissue, as shown by signal transducer and activator of transcription and CAAT/enhancer binding protein-β phosphorylation and IL-6-responsive gene mRNA levels at the end of exercise. Recombinant IL-6 injection resulted in an increase in IL-6-responsive gene mRNA levels in the liver. We found a dose-dependent increase in PEPCK gene mRNA strongly correlated with IL-6-induced gene mRNA levels. No changes in G6P and PGC-1α mRNA levels were found. Taken together, our results suggest that, during very demanding exercise, muscle-derived IL-6 could help increase HGP by directly upregulating PEPCK mRNA abundance.

Increased hepatic glucose production response to glucagon in trained subjects

1998 ◽  
Vol 274 (1) ◽  
pp. E23-E28 ◽  
Author(s):  
Réjean Drouin ◽  
Carole Lavoie ◽  
Josée Bourque ◽  
Francine Ducros ◽  
Danielle Poisson ◽  
...  
Keyword(s):  
Endurance Training ◽  
Hepatic Glucose Production ◽  
Area Under The Curve ◽  
Glucose Production ◽  
Trained Subjects ◽  
Endogenous Insulin ◽  
Hepatic Glucose ◽  
Glucagon And Insulin ◽  
The Impact ◽  
Male Subjects

This study was designed to characterize the impact of endurance training on the hepatic response to glucagon. We measured the effect of glucagon on hepatic glucose production (HGP) in resting trained ( n = 8) and untrained ( n = 8) healthy male subjects (maximal rate of O2 consumption: 65.9 ± 1.6 vs. 46.8 ± 0.6 ml O2 ⋅ kg−1 ⋅ min−1, respectively, P < 0.001). Endogenous insulin and glucagon were suppressed by somatostatin (somatotropin release-inhibiting hormone) infusion (450 μg/h) over 4 h. Insulin (0.15 mU ⋅ kg−1 ⋅ min−1) was infused throughout the study, and glucagon (1.5 ng ⋅ kg−1 ⋅ min−1) was infused over the last 2 h. During the latter period, plasma glucagon and insulin remained constant at 138.2 ± 3.1 vs. 145.3 ± 2.1 ng/l and at 95.5 ± 4.5 vs. 96.2 ± 1.9 pmol/l in trained and untrained subjects, respectively. Plasma glucose increased and peaked at 11.4 ± 1.1 mmol/l in trained subjects and at 8.9 ± 0.8 mmol/l in untrained subjects ( P < 0.001). During glucagon stimulation, the mean increase in HGP area under the curve was 15.8 ± 2.8 mol ⋅ kg−1 ⋅ min−1in trained subjects compared with 7.4 ± 1.6 mol ⋅ kg−1 ⋅ min−1in untrained subjects ( P < 0.01) over the first hour and declined to 6.8 ± 2.8 and 4.9 ± 1.4 mol ⋅ kg−1 ⋅ min−1during the second hour. In conclusion, these observations indicate that endurance training is associated with an increase in HGP in response to physiological levels of glucagon, thus suggesting an increase in hepatic glucagon sensitivity.

scholarly journals Arrestin domain-containing 3 (Arrdc3) modulates insulin action and glucose metabolism in liver

2020 ◽  
Vol 117 (12) ◽  
pp. 6733-6740 ◽  
Author(s):  
Thiago M. Batista ◽  
Sezin Dagdeviren ◽  
Shannon H. Carroll ◽  
Weikang Cai ◽  
Veronika Y. Melnik ◽  
...  
Keyword(s):  
Messenger Rna ◽  
Insulin Action ◽  
Hepatic Glucose Production ◽  
Glycogen Synthesis ◽  
Glucose Production ◽  
Hepatic Glycogen ◽  
Glycogen Accumulation ◽  
Hepatic Glucose ◽  
Glucose Output

Insulin action in the liver is critical for glucose homeostasis through regulation of glycogen synthesis and glucose output. Arrestin domain-containing 3 (Arrdc3) is a member of the α-arrestin family previously linked to human obesity. Here, we show thatArrdc3is differentially regulated by insulin in vivo in mice undergoing euglycemic-hyperinsulinemic clamps, being highly up-regulated in liver and down-regulated in muscle and fat. Mice with liver-specific knockout (KO) of the insulin receptor (IR) have a 50% reduction inArrdc3messenger RNA, while, conversely, mice with liver-specific KO ofArrdc3(L-Arrdc3KO) have increased IR protein in plasma membrane. This leads to increased hepatic insulin sensitivity with increased phosphorylation of FOXO1, reduced expression of PEPCK, and increased glucokinase expression resulting in reduced hepatic glucose production and increased hepatic glycogen accumulation. These effects are due to interaction of ARRDC3 with IR resulting in phosphorylation of ARRDC3 on a conserved tyrosine (Y382) in the carboxyl-terminal domain. Thus,Arrdc3is an insulin target gene, and ARRDC3 protein directly interacts with IR to serve as a feedback regulator of insulin action in control of liver metabolism.

scholarly journals The Δ337T mutation on the TRβ causes alterations in growth, adiposity, and hepatic glucose homeostasis in mice

2011 ◽  
Vol 211 (1) ◽  
pp. 39-46 ◽  
Author(s):  
L A Santiago ◽  
D A Santiago ◽  
L C Faustino ◽  
A Cordeiro ◽  
P C Lisboa ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Thyroid Hormone Receptor ◽  
Hepatic Glucose Production ◽  
Glucose Production ◽  
Dominant Negative ◽  
Dominant Negative Effect ◽  
Hepatic Glycogen ◽  
Dominant Negative Mutation ◽  
Hepatic Glucose

Mice bearing the genomic mutation Δ337T on the thyroid hormone receptor β (TRβ) gene present the classical signs of resistance to thyroid hormone (TH), with high serum TH and TSH. This mutant TR is unable to bind TH, remains constitutively bound to co-repressors, and has a dominant negative effect on normal TRs. In this study, we show that homozygous (TRβΔ337T) mice for this mutation have reduced body weight, length, and body fat content, despite augmented relative food intake and relative increase in serum leptin. TRβΔ337T mice exhibited normal glycemia and were more tolerant to an i.p. glucose load accompanied by reduced insulin secretion. Higher insulin sensitivity was observed after single insulin injection, when the TRβΔ337T mice developed a profound hypoglycemia. Impaired hepatic glucose production was confirmed by the reduction in glucose generation after pyruvate administration. In addition, hepatic glycogen content was lower in homozygous TRβΔ337T mice than in wild type. Collectively, the data suggest that TRβΔ337T mice have deficient hepatic glucose production, by reduced gluconeogenesis and lower glycogen deposits. Analysis of liver gluconeogenic gene expression showed a reduction in the mRNA of phosphoenolpyruvate carboxykinase, a rate-limiting enzyme, and of peroxisome proliferator-activated receptor-γ coactivator 1α, a key transcriptional factor essential to gluconeogenesis. Reduction in both gene expressions is consistent with resistance to TH action via TRβ, reproducing a hypothyroid phenotype. In conclusion, mice carrying the Δ337T-dominant negative mutation on the TRβ are leaner, exhibit impaired hepatic glucose production, and are more sensitive to hypoglycemic effects of insulin.

Lack of effect of β-endorphin on basal or glucagon-stimulated hepatic glucose production in vitro

Metabolism ◽  
1987 ◽  
Vol 36 (5) ◽  
pp. 432-437 ◽  
Author(s):  
Patricia L. Brubaker ◽  
Alexander Sun ◽  
Mladen Vranic
Keyword(s):  
Hepatic Glucose Production ◽  
Glucose Production ◽  
Hepatic Glucose
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