scholarly journals A physiological increase in the hepatic glycogen level does not affect the response of net hepatic glucose uptake to insulin

2009 ◽  
Vol 297 (2) ◽  
pp. E358-E366 ◽  
Author(s):  
Jason J. Winnick ◽  
Zhibo An ◽  
Mary Courtney Moore ◽  
Christopher J. Ramnanan ◽  
Ben Farmer ◽  
...  

To determine the effect of an acute increase in hepatic glycogen on net hepatic glucose uptake (NHGU) and disposition in response to insulin in vivo, studies were performed on two groups of dogs fasted 18 h. During the first 4 h of the study, somatostatin was infused peripherally, while insulin and glucagon were replaced intraportally in basal amounts. Hyperglycemia was brought about by glucose infusion, and either saline ( n = 7) or fructose ( n = 7; to stimulate NHGU and glycogen deposition) was infused intraportally. A 2-h control period then followed, during which the portal fructose and saline infusions were stopped, allowing NHGU and glycogen deposition in the fructose-infused animals to return to rates similar to those of the animals that received the saline infusion. This was followed by a 2-h experimental period, during which hyperglycemia was continued but insulin infusion was increased fourfold in both groups. During the initial 4-h glycogen loading period, NHGU averaged 1.18 ± 0.27 and 5.55 ± 0.53 mg·kg−1·min−1 and glycogen synthesis averaged 0.72 ± 0.24 and 3.98 ± 0.57 mg·kg−1·min−1 in the saline and fructose groups, respectively ( P < 0.05). During the 2-h hyperinsulinemic period, NHGU rose from 1.5 ± 0.4 and 0.9 ± 0.2 to 3.1 ± 0.6 and 2.5 ± 0.5 mg·kg−1·min−1 in the saline and fructose groups, respectively, a change of 1.6 mg·kg−1·min−1 in both groups despite a significantly greater liver glycogen level in the fructose-infused group. Likewise, the metabolic fate of the extracted glucose (glycogen, lactate, or carbon dioxide) was not different between groups. These data indicate that an acute physiological increase in the hepatic glycogen content does not alter liver glucose uptake and storage under hyperglycemic/hyperinsulinemic conditions in the dog.

2000 ◽  
Vol 279 (1) ◽  
pp. E108-E115
Author(s):  
Owen P. McGuinness ◽  
Joseph Ejiofor ◽  
D. Brooks Lacy ◽  
Nancy Schrom

We previously reported that infection decreases hepatic glucose uptake when glucose is given as a constant peripheral glucose infusion (8 mg · kg−1· min−1). This impairment persisted despite greater hyperinsulinemia in the infected group. In a normal setting, hepatic glucose uptake can be further enhanced if glucose is given gastrointestinally. Thus the aim of this study was to determine whether hepatic glucose uptake is impaired during an infection when glucose is given gastrointestinally. Thirty-six hours before study, a sham (SH, n = 7) or Escherichia coli-containing (2 × 109organisms/kg; INF; n = 7) fibrin clot was placed in the peritoneal cavity of chronically catheterized dogs. After the 36 h, a glucose bolus (150 mg/kg) followed by a continuous infusion (8 mg · kg−1· min−1) of glucose was given intraduodenally to conscious dogs for 240 min. Tracer ([3-3H]glucose and [U-14C]glucose) and arterial-venous difference techniques were used to assess hepatic and intestinal glucose metabolism. Infection increased hepatic blood flow (35 ± 5 vs. 47 ± 3 ml · kg−1· min−1; SH vs. INF) and basal glucose rate of appearance (2.1 ± 0.2 vs. 3.3 ± 0.1 mg · kg−1· min−1). Arterial insulin concentrations increased similarly in SH and INF during the last hour of glucose infusion (38 ± 8 vs. 46 ± 20 μU/ml), and arterial glucagon concentrations fell (62 ± 14 to 30 ± 3 vs. 624 ± 191 to 208 ± 97 pg/ml). Net intestinal glucose absorption was decreased in INF, attenuating the increase in blood glucose caused by the glucose load. Despite this, net hepatic glucose uptake (1.6 ± 0.8 vs. 2.4 ± 0.9 mg · kg−1· min−1; SH vs. INF) and consequently tracer-determined glycogen synthesis (1.3 ± 0.3 vs. 1.0 ± 0.3 mg · kg−1· min−1) were similar between groups. In summary, infection impairs net glucose absorption, but not net hepatic glucose uptake or glycogen deposition, when glucose is given intraduodenally.


2005 ◽  
Vol 288 (6) ◽  
pp. E1160-E1167 ◽  
Author(s):  
Masakazu Shiota ◽  
Pietro Galassetti ◽  
Kayano Igawa ◽  
Doss W. Neal ◽  
Alan D. Cherrington

The effect of small amounts of fructose on net hepatic glucose uptake (NHGU) during hyperglycemia was examined in the presence of insulinopenia in conscious 42-h fasted dogs. During the study, somatostatin (0.8 μg·kg−1·min−1) was given along with basal insulin (1.8 pmol·kg−1·min−1) and glucagon (0.5 ng·kg−1·min−1). After a control period, glucose (36.1 μmol·kg−1·min−1) was continuously given intraportally for 4 h with (2.2 μmol·kg−1·min−1) or without fructose. In the fructose group, the sinusoidal blood fructose level (nmol/ml) rose from <16 to 176 ± 11. The infusion of glucose alone (the control group) elevated arterial blood glucose (μmol/ml) from 4.3 ± 0.3 to 11.2 ± 0.6 during the first 2 h after which it remained at 11.6 ± 0.8. In the presence of fructose, glucose infusion elevated arterial blood glucose (μmol/ml) from 4.3 ± 0.2 to 7.4 ± 0.6 during the first 1 h after which it decreased to 6.1 ± 0.4 by 180 min. With glucose infusion, net hepatic glucose balance (μmol·kg−1·min−1) switched from output (8.9 ± 1.7 and 13.3 ± 2.8) to uptake (12.2 ± 4.4 and 29.4 ± 6.7) in the control and fructose groups, respectively. Average NHGU (μmol·kg−1·min−1) and fractional glucose extraction (%) during last 3 h of the test period were higher in the fructose group (30.6 ± 3.3 and 14.5 ± 1.4) than in the control group (15.0 ± 4.4 and 5.9 ± 1.8). Glucose 6-phosphate and glycogen content (μmol glucose/g) in the liver and glucose incorporation into hepatic glycogen (μmol glucose/g) were higher in the fructose (218 ± 2, 283 ± 25, and 109 ± 26, respectively) than in the control group (80 ± 8, 220 ± 31, and 41 ± 5, respectively). In conclusion, small amounts of fructose can markedly reduce hyperglycemia during intraportal glucose infusion by increasing NHGU even when insulin secretion is compromised.


1999 ◽  
Vol 276 (2) ◽  
pp. E295-E302 ◽  
Author(s):  
Mary Courtney Moore ◽  
Po-Shiuan Hsieh ◽  
Paul J. Flakoll ◽  
Doss W. Neal ◽  
Alan D. Cherrington

Concomitant portal infusion of gluconeogenic amino acids (GNGAA) and glucose significantly reduces net hepatic glucose uptake (NHGU), in comparison with NHGU during portal infusion of glucose alone. To determine whether this effect on NHGU is specific to the portal route of GNGAA delivery, somatostatin, intraportal insulin (3-fold basal) and glucagon (basal), and intraportal glucose (to increase the hepatic glucose load by ∼50%) were infused for 240 min. GNGAA were infused peripherally into a group of dogs (PeAA), at a rate to match the hepatic GNGAA load in a group of dogs that were given the same GNGAA mixture intraportally (PoAA) at 7.6 μmol ⋅ kg−1 ⋅ min−1(9). The arterial blood glucose concentrations and hepatic glucose loads were the same in the two groups, but NHGU (−0.9 ± 0.2 PoAA and −2.1 ± 0.5 mg ⋅ kg−1 ⋅ min−1in PeAA, P < 0.05) and net hepatic fractional extraction of glucose (2.6 ± 0.7% in PoAA vs. 5.9 ± 1.4% in PeAA, P < 0.05) differed. Neither the hepatic loads nor the net hepatic uptakes of GNGAA were significantly different in the two groups. Net hepatic glycogen synthesis was ∼2.5-fold greater in PeAA than PoAA ( P < 0.05). Intraportal, but not peripheral, amino acid infusion suppresses NHGU and net hepatic glycogen synthesis in response to intraportal glucose infusion.


1995 ◽  
Vol 269 (2) ◽  
pp. E199-E207 ◽  
Author(s):  
O. P. McGuinness ◽  
J. Jacobs ◽  
C. Moran ◽  
B. Lacy

The effect of infection on hepatic uptake and disposal of a continuous (180-min) intravenous glucose infusion (8 mg.kg-1.min-1) was examined in conscious, 54-h-fasted, chronically catheterized dogs. Thirty-six hours before a study, either infection was induced by implantation of an Escherichia coli-containing (INF; 2 x 10(9) organisms/kg body wt; n = 6) fibrinogen clot, or a sterile (SH; n = 6) clot was implanted into the peritoneal cavity. Hepatic glucose metabolism was assessed using tracer ([3-3H]glucose and [U-14C]glucose) and arteriovenous difference techniques. Infection increased the basal rate of glucose appearance (45%); glucose levels were not altered. In response to glucose infusion, average blood glucose levels increased to similar levels (140 +/- 9 vs. 147 +/- 11 mg/dl in INF and SH, respectively), whereas arterial insulin levels were higher in the infected group during the last hour of the glucose infusion (77 +/- 10 vs. 41 +/- 5 microU/ml in INF vs. SH). Infection impaired net hepatic glucose uptake (0.6 +/- 0.5 and 2.7 +/- 0.7 mg.kg-1.min-1 in INF and SH; P < 0.05). The liver remained a persistent lactate consumer (4.1 +/- 1.8 mumol.kg-1.min-1), whereas the sham group became a net producer of lactate (-3.8 +/- 1.3 mumol.kg-1.min-1). Infection decreased net hepatic glycogen deposition by 53%. In conclusion, infection impairs net hepatic glucose uptake and glycogen deposition despite an exaggerated increase in insulin levels.


2015 ◽  
Vol 308 (10) ◽  
pp. E860-E867 ◽  
Author(s):  
Katie C. Coate ◽  
Guillaume Kraft ◽  
Masakazu Shiota ◽  
Marta S. Smith ◽  
Ben Farmer ◽  
...  

Dogs consuming a hypercaloric high-fat and -fructose diet (52 and 17% of total energy, respectively) or a diet high in either fructose or fat for 4 wk exhibited blunted net hepatic glucose uptake (NHGU) and glycogen deposition in response to hyperinsulinemia, hyperglycemia, and portal glucose delivery. The effect of a hypercaloric diet containing neither fructose nor excessive fat has not been examined. Dogs with an initial weight of ≈25 kg consumed a chow and meat diet (31% protein, 44% carbohydrate, and 26% fat) in weight-maintaining (CTR; n = 6) or excessive (Hkcal; n = 7) amounts for 4 wk (cumulative weight gain 0.0 ± 0.3 and 1.5 ± 0.5 kg, respectively, P < 0.05). They then underwent clamp studies with infusions of somatostatin and intraportal insulin (4× basal) and glucagon (basal). The hepatic glucose load was doubled with peripheral (Pe) glucose infusion for 90 min (P1) and intraportal glucose at 4 mg·kg−1·min−1 plus Pe glucose for the final 90 min (P2). NHGU was blunted ( P < 0.05) in Hkcal during both periods (mg·kg−1·min−1; P1: 1.7 ± 0.2 vs. 0.3 ± 0.4; P2: 3.6 ± 0.3 vs. 2.3 ± 0.4, CTR vs. Hkcal, respectively). Terminal hepatic glucokinase catalytic activity was reduced nearly 50% in Hkcal vs. CTR ( P < 0.05), although glucokinase protein did not differ between groups. In Hkcal vs. CTR, liver glycogen was reduced 27% ( P < 0.05), with a 91% increase in glycogen phosphorylase activity ( P < 0.05) but no significant difference in glycogen synthase activity. Thus, Hkcal impaired NHGU and glycogen synthesis compared with CTR, indicating that excessive energy intake, even if the diet is balanced and nutritious, negatively impacts hepatic glucose metabolism.


1996 ◽  
Vol 271 (2) ◽  
pp. E215-E222 ◽  
Author(s):  
M. C. Moore ◽  
L. Rossetti ◽  
M. J. Pagliassotti ◽  
M. Monahan ◽  
C. Venable ◽  
...  

The role of the liver nerves in the disposition of peripherally administered glucose was examined in seven hepatic innervated (HI) and nine hepatic denervated (HD) 42-h-fasted conscious dogs. After a 40-min basal period, there was a 4-h experimental period during which the hepatic glucose load was increased twofold via peripheral glucose infusion. Somatostatin was infused to suppress pancreatic endocrine secretion, and insulin and glucagon were infused intraportally to produce a fourfold increase in insulin and a gradual decrease (approximately 25%) in glucagon. The area under the curve of net hepatic glucose uptake (NHGU) during the glucose infusion period totaled 483 +/- 82 and 335 +/- 32 mg/kg in HD and HI, respectively (P < 0.05). The area under the curve of the hepatic fractional extraction of glucose was 27% greater in HD (P < 0.05). Net hepatic lactate output was similar in the two groups, and net hepatic glycogen synthesis was 3.8 +/- 0.8 vs. 2.7 +/- 0.5 mg.kg dog wt-1.min-1 in HD and HI, respectively (P = 0.13). The direct pathway of glycogen synthesis was responsible for 54-58% of net hepatic glycogen synthesis in both HI and HD (n = 6 for both). In summary 1) NHGU in response to peripheral glucose infusion was approximately 44% greater in HD than in HI, 2) net hepatic glycogen synthesis was enhanced by 41% in HD although the probability of this change was 0.13, and 3) the contribution of the direct pathway to glycogen synthesis was the same in HD and HI. These data are consistent with a role for the liver nerves in regulating the magnitude of NHGU in response to glucose administration. They also indicate that the absence of liver nerves may reduce glycogen turnover during glucose infusion.


2008 ◽  
Vol 294 (2) ◽  
pp. E300-E306 ◽  
Author(s):  
Zhibo An ◽  
Catherine A. DiCostanzo ◽  
Mary C. Moore ◽  
Dale S. Edgerton ◽  
Dominique P. Dardevet ◽  
...  

To determine the role of nitric oxide in regulating net hepatic glucose uptake (NHGU) in vivo, studies were performed on three groups of 42-h-fasted conscious dogs using a nitric oxide donor [3-morpholinosydnonimine (SIN-1)]. The experimental period was divided into period 1 (0–90 min) and period 2 (P2; 90–240 min). At 0 min, somatostatin was infused peripherally, and insulin (4-fold basal) and glucagon (basal) were given intraportally. Glucose was delivered intraportally (22.2 μmol·kg−1·min−1) and peripherally (as needed) to increase the hepatic glucose load twofold basal. At 90 min, an infusion of SIN-1 (4 μg·kg−1·min−1) was started in a peripheral vein (PeSin-1, n = 10) or the portal vein (PoSin-1, n = 12) while the control group received saline (SAL, n = 8). Both peripheral and portal infusion of SIN-1, unlike saline, significantly reduced systolic and diastolic blood pressure. Heart rate rose in PeSin-1 and PoSin-1 (96 ± 5 to 120 ± 10 and 88 ± 6 to 107 ± 5 beats/min, respectively, P < 0.05) but did not change in response to saline. NHGU during P2 was 31.0 ± 2.4 and 29.9 ± 2.0 μmol·kg−1·min−1 in SAL and PeSin-1, respectively but was 23.7 ± 1.7 in PoSin-1 ( P < 0.05). Net hepatic carbon retention during P2 was significantly lower in PoSin-1 than SAL or PeSin-1 (21.4 ± 1.2 vs. 27.1 ± 1.5 and 26.1 ± 1.0 μmol·kg−1·min−1). Nonhepatic glucose uptake did not change in response to saline or SIN-1 infusion. In conclusion, portal but not peripheral infusion of the nitric oxide donor SIN-1 inhibited NHGU.


1998 ◽  
Vol 274 (5) ◽  
pp. E893-E902 ◽  
Author(s):  
Mary Courtney Moore ◽  
Paul J. Flakoll ◽  
Po-Shiuan Hsieh ◽  
Michael J. Pagliassotti ◽  
Doss W. Neal ◽  
...  

The effect of concomitant intraportal infusion of glucose and gluconeogenic amino acids (AA) on net hepatic glucose uptake (NHGU) and glycogen synthesis was examined in 42-h-fasted dogs. After a basal period, there was a 240-min experimental period during which somatostatin was infused continuously into a peripheral vein and insulin and glucagon (at 3-fold basal and basal rates, respectively) and glucose (18.3 μmol ⋅ kg−1⋅ min−1) were infused intraportally. One group (PoAA, n = 7) received an AA mixture intraportally at 7.6 μmol ⋅ kg−1⋅ min−1, whereas the other group (NoAA, n = 6) did not receive AA. Arterial blood glucose concentrations and hepatic glucose loads were the same in the two groups. NHGU averaged 4.8 ± 2.0 (PoAA) and 9.4 ± 2.0 (NoAA) μmol ⋅ kg−1⋅ min−1( P < 0.05), and tracer-determined hepatic glucose uptake was 4.6 ± 1.6 (PoAA) and 10.0 ± 1.7 (NoAA) μmol ⋅ kg−1⋅ min−1( P < 0.05). AA data for PoAA and NoAA, respectively, were as follows: arterial blood concentrations, 1,578 ± 133 vs. 1,147 ± 86 μM ( P < 0.01); hepatic loads, 56 ± 3 vs. 32 ± 4 μmol ⋅ kg−1⋅ min−1( P < 0.01); and net hepatic uptakes, 14.1 ± 1.4 vs. 5.6 ± 0.4 μmol ⋅ kg−1⋅ min−1( P < 0.01). The rate of net hepatic glycogen synthesis was 7.5 ± 1.9 (PoAA) vs. 10.7 ± 2.3 (NoAA) μmol ⋅ kg−1⋅ min−1( P = 0.1). In a net sense, intraportal gluconeogenic amino acid delivery directed glucose carbon away from the liver. Despite this, net hepatic carbon uptake was equivalent in the presence and absence of amino acid infusion.


1976 ◽  
Vol 156 (3) ◽  
pp. 585-592 ◽  
Author(s):  
P D Whitton ◽  
D A Hems

1. A total loss of capacity for net glycogen synthesis was observed in experiments with the perfused liver of starved adrenalectomized rats. 2. This lesion was corrected by insulin or cortisol in vivo (over 2-5h), but not by any agent tested in perfusion. 3. The activity of glycogen synthetase a, and its increase during perfusion, in the presence of glucose plus glucogenic substrates, were proportional to the rate of net glycogen accumulation. 4. This complete inherent loss of capacity for glycogen synthesis after adrenalectomy is greater than any defect in hepatic metabolism yet reported in this situation, and is not explicable by a decrease in the rate of gluconegenesis (which supports glycogen synthesis in the liver of starved rats). The short-term (2-5h) stimulatory effect of glucocorticoids in the intact animal, on hepatic glycogen deposition, may be mediated partly through insulin action, although neither insulin or cortisol appear to act directly on the liver to stimulate glycogen synthesis.


2020 ◽  
Vol 117 (12) ◽  
pp. 6733-6740 ◽  
Author(s):  
Thiago M. Batista ◽  
Sezin Dagdeviren ◽  
Shannon H. Carroll ◽  
Weikang Cai ◽  
Veronika Y. Melnik ◽  
...  

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.


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