scholarly journals Chronic overeating impairs hepatic glucose uptake and disposition

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.

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.


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.


2014 ◽  
Vol 307 (2) ◽  
pp. E151-E160 ◽  
Author(s):  
Katie C. Coate ◽  
Guillaume Kraft ◽  
Mary Courtney Moore ◽  
Marta S. Smith ◽  
Christopher Ramnanan ◽  
...  

In dogs consuming a high-fat and -fructose diet (52 and 17% of total energy, respectively) for 4 wk, hepatic glucose uptake (HGU) in response to hyperinsulinemia, hyperglycemia, and portal glucose delivery is markedly blunted with reduction in glucokinase (GK) protein and glycogen synthase (GS) activity. The present study compared the impact of selective increases in dietary fat and fructose on liver glucose metabolism. Dogs consumed weight-maintaining chow (CTR) or hypercaloric high-fat (HFA) or high-fructose (HFR) diets diet for 4 wk before undergoing clamp studies with infusion of somatostatin and intraportal insulin (3–4 times basal) and glucagon (basal). The hepatic glucose load (HGL) was doubled during the clamp using peripheral vein (Pe) glucose infusion in the first 90 min (P1) and portal vein (4 mg·kg−1·min−1) plus Pe glucose infusion during the final 90 min (P2). During P2, HGU was 2.8 ± 0.2, 1.0 ± 0.2, and 0.8 ± 0.2 mg·kg−1·min−1 in CTR, HFA, and HFR, respectively ( P < 0.05 for HFA and HFR vs. CTR). Compared with CTR, hepatic GK protein and catalytic activity were reduced ( P < 0.05) 35 and 56%, respectively, in HFA, and 53 and 74%, respectively, in HFR. Liver glycogen concentrations were 20 and 38% lower in HFA and HFR than CTR ( P < 0.05). Hepatic Akt phosphorylation was decreased ( P < 0.05) in HFA (21%) but not HFR. Thus, HFR impaired hepatic GK and glycogen more than HFA, whereas HFA reduced insulin signaling more than HFR. HFA and HFR effects were not additive, suggesting that they act via the same mechanism or their effects converge at a saturable step.


1997 ◽  
Vol 273 (3) ◽  
pp. E488 ◽  
Author(s):  
L C Holste ◽  
C C Connolly ◽  
M C Moore ◽  
D W Neal ◽  
A D Cherrington

This study examined whether physiological changes in glucagon alter net hepatic glucose uptake (NHGU) or glycogen synthesis under conditions of hyperglycemia, hyperinsulinemia, and portal vein glucose concentrations exceeding those in the arterial circulation. Somatostatin was infused into 42-h-fasted dogs, insulin and glucagon were replaced intraportally at basal rates, and peripheral infusion of glucose maintained the hepatic glucose load twofold basal for 90 min (period 1). In period 2 (240 min) the insulin infusion was increased fourfold, glucose was infused intraportally, the hepatic glucose load was twofold basal, and glucagon was infused to create levels 150% basal (HiGGN, n = 6) or 40% basal (LoGGN, n = 6). NHGU rates (mg.kg-1.min-1) were low during period 1 (-0.9 +/- 0.7 in LoGGN and -0.2 +/- 0.4 in HiGGN, not significant) but increased during period 2 (-4.1 +/- 0.6 in LoGGN and -1.9 +/- 0.2 in HiGGN, P < 0.05). Endogenous glucose production (Endo Ra) declined during period 2 in LoGGN (P < 0.01 vs. basal) but did not change in HiGGN. Tracer-determined hepatic glucose uptake did not differ between groups. The poststudy increment in liver glycogen synthase I (12.5 +/- 3 vs. 6.5 +/- 2% of total) was greater in LoGGN (P < 0.05), as was net glycogen synthesis (27 +/- 8 vs. 13 +/- 3 mg/g liver, P = 0.06). An elevation in glucagon reduced NHGU (because of failure to suppress Endo Ra) and glycogen synthase activation and tended to reduce glycogen deposition.


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.


2001 ◽  
Vol 280 (5) ◽  
pp. E703-E711 ◽  
Author(s):  
Christine M. Donmoyer ◽  
Joseph Ejiofor ◽  
D. Brooks Lacy ◽  
Sheng-Song Chen ◽  
Owen P. McGuinness

During chronic total parenteral nutrition (TPN), net hepatic glucose uptake (NHGU) and net hepatic lactate release (NHLR) are markedly reduced (↓∼45 and ∼65%, respectively) with infection. Because small quantities of fructose are known to augment hepatic glucose uptake and lactate release in normal fasted animals, the aim of this work was to determine whether acute fructose infusion with TPN could correct the impairments in NHGU and NHLR during infection. Chronically catheterized conscious dogs received TPN for 5 days via the inferior vena cava at a rate designed to match daily basal energy requirements. On the third day of TPN administration, a sterile (SHAM, n = 12) or Escherichia coli-containing (INF, n = 11) fibrin clot was implanted in the peritoneal cavity. Forty-two hours later, somatostatin was infused with intraportal replacement of insulin (12 ± 2 vs. 24 ± 2 μU/ml, SHAM vs. INF, respectively) and glucagon (24 ± 4 vs. 92 ± 5 pg/ml) to match concentrations previously observed in sham and infected animals. After a 120-min basal period, animals received either saline (Sham+S, n = 6; Inf+S, n = 6) or intraportal fructose (0.7 mg · kg−1· min−1; Sham+F, n = 6; Inf+F, n = 5) infusion for 180 min. Isoglycemia of 120 mg/dl was maintained with a variable glucose infusion. Combined tracer and arteriovenous difference techniques were used to assess hepatic glucose metabolism. Acute fructose infusion with TPN augmented NHGU by 2.9 ± 0.4 and 2.5 ± 0.3 mg · kg−1· min−1in Sham+F and Inf+F, respectively. The majority of liver glucose uptake was stored as glycogen, and NHLR did not increase substantially. Therefore, despite an infection-induced impairment in NHGU and different hormonal environments, small amounts of fructose enhanced NHGU similarly in sham and infected animals. Glycogen storage, not lactate release, was the preferential fate of the fructose-induced increase in hepatic glucose disposal in animals adapted to TPN.


2010 ◽  
Vol 299 (6) ◽  
pp. E887-E898 ◽  
Author(s):  
Katie Colbert Coate ◽  
Melanie Scott ◽  
Ben Farmer ◽  
Mary Courtney Moore ◽  
Marta Smith ◽  
...  

The objective of this study was to assess the response of a large animal model to high dietary fat and fructose (HFFD). Three different metabolic assessments were performed during 13 wk of feeding an HFFD ( n = 10) or chow control (CTR, n = 4) diet: oral glucose tolerance tests (OGTTs; baseline, 4 and 8 wk), hyperinsulinemic-euglycemic clamps (HIEGs; baseline and 10 wk) and hyperinsulinemic-hyperglycemic clamps (HIHGs, 13 wk). The ΔAUC for glucose during the OGTTs more than doubled after 4 and 8 wk of HFFD feeding, and the average glucose infusion rate required to maintain euglycemia during the HIEG clamps decreased by ≈30% after 10 wk of HFFD feeding. These changes did not occur in the CTR group. The HIHG clamps included experimental periods 1 (P1, 0–90 min) and 2 (P2, 90–180 min). During P1, somatostatin, basal intraportal glucagon, 4 × basal intraportal insulin, and peripheral glucose (to double the hepatic glucose load) were infused; during P2, glucose was also infused intraportally (4.0 mg·kg−1·min−1). Net hepatic glucose uptake during P1 and P2 was −0.4 ± 0.1 [output] and 0.2 ± 0.8 mg·kg−1·min−1 in the HFFD group, respectively, and 1.8 ± 0.8 and 3.5 ± 1.0 mg·kg−1·min−1 in the CTR group, respectively ( P < 0.05 vs. HFFD during P1 and P2). Glycogen synthesis through the direct pathway was 0.5 ± 0.2 and 1.5 ± 0.4 mg·kg−1·min−1 in the HFFD and CTR groups, respectively ( P < 0.05 vs. HFFD). In conclusion, chronic consumption of an HFFD diminished the sensitivity of the liver to hormonal and glycemic cues and resulted in a marked impairment in NHGU and glycogen synthesis.


2000 ◽  
Vol 278 (3) ◽  
pp. E544-E552 ◽  
Author(s):  
Masakazu Shiota ◽  
Patricia Jackson ◽  
Pietro Galassetti ◽  
Melanie Scott ◽  
Doss W. Neal ◽  
...  

Portal glucose delivery in the conscious dog augments net hepatic glucose uptake (NHGU). To investigate the possible role of altered autonomic nervous activity in the effect of portal glucose delivery, the effects of adrenergic blockade and acetylcholine (ACh) on hepatic glucose metabolism were examined in 42-h-fasted conscious dogs. Each study consisted of an equilibration (−120 to −20 min), a control (−20 to 0 min), and a hyperglycemic-hyperinsulinemic period (0 to 300 min). During the last period, somatostatin (0.8 μg ⋅ kg−1⋅ min−1) was infused along with intraportal insulin (1.2 mU ⋅ kg−1⋅ min−1) and glucagon (0.5 ng ⋅ kg−1⋅ min−1). Hepatic sinusoidal insulin was four times basal (73 ± 7 μU/ml) and glucagon was basal (55 ± 7 pg/ml). Glucose was infused peripherally (0–300 min) to create hyperglycemia (220 mg/dl). In test protocol, phentolamine and propranolol were infused intraportally at 0.2 μg and 0.1 μg ⋅ kg−1⋅ min−1from 120 min on. ACh was infused intraportally at 3 μg ⋅ kg−1⋅ min−1from 210 min on. In control protocol, saline was given in place of the blockers and ACh. Hyperglycemia-hyperinsulinemia switched the net hepatic glucose balance (mg ⋅ kg−1⋅ min−1) from output (2.1 ± 0.3 and 1.1 ± 0.2) to uptake (2.8 ± 0.9 and 2.6 ± 0.6) and lactate balance (μmol ⋅ kg−1⋅ min−1) from uptake (7.5 ± 2.2 and 6.7 ± 1.6) to output (3.7 ± 2.6 and 3.9 ± 1.6) by 120 min in the control and test protocols, respectively. Therefter, in the control protocol, NHGU tended to increase slightly (3.0 ± 0.6 mg ⋅ kg−1⋅ min−1by 300 min). In the test protocol, adrenergic blockade did not alter NHGU, but ACh infusion increased it to 4.4 ± 0.6 and 4.6 ± 0.6 mg ⋅ kg−1⋅ min−1by 220 and 300 min, respectively. These data are consistent with the hypothesis that alterations in nerve activity contribute to the increase in NHGU seen after portal glucose delivery.


1993 ◽  
Vol 265 (3) ◽  
pp. E487-E496 ◽  
Author(s):  
M. C. Moore ◽  
G. I. Shulman ◽  
A. Giaccari ◽  
M. J. Pagliassotti ◽  
G. Cline ◽  
...  

We examined the disposition of a continuous 4-h intraduodenal glucose infusion (8 mg.kg-1 x min-1, labeled with [1-13C]glucose and [3-3H]glucose) in nine conscious hepatic-denervated dogs. Cumulative net hepatic uptakes (in grams of glucose equivalents) were 13.7 +/- 2.5 glucose, 3.1 +/- 0.6 gluconeogenic amino acids, and 0.8 +/- 0.1 glycerol. Net hepatic glycogen synthesis totalled 11.0 +/- 0.9 g, 55-62% via the direct pathway. All values were similar to those in hepatic-innervated dogs. Glycogen synthase activity and rate of glycogen synthesis were positively correlated (r2 = 0.913, P < 0.05). Variability in net hepatic glycogen synthesis and the mass of glycogen synthesized via the indirect pathway was reduced in hepatic-denervated dogs (P < 0.05). In conclusion, the glycemic response and rate of net glycogen synthesis during an intraduodenal glucose infusion was no different in hepatic-denervated and -innervated dogs. Net hepatic glucose uptake was sufficient to account for all net hepatic glycogen synthesis and lactate production, consistent with an intrahepatic source of gluconeogenic precursors for glycogen synthesis via the indirect pathway. Hepatic nerves appear responsible for much of the variability in net hepatic glycogen synthesis and in the mass of glycogen synthesized via the indirect pathway in normal dogs.


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