Intrahepatic glucose: a requirement for neonatal ODC induction by specific hormones

1984 ◽  
Vol 247 (2) ◽  
pp. E243-E250
Author(s):  
G. Evoniuk ◽  
C. Kuhn ◽  
S. Schanberg

We have shown previously that short-term nutritional deprivation causes a tissue-specific loss of liver ornithine decarboxylase (ODC) induction after isoproterenol, phenylephrine, or glucagon administration in rat pups. To examine the role of nutrition in the regulation of hepatic ODC, we tested the ability of intragastric nutrient administration to reverse nutritionally related deficits in the ODC response to hormonal challenge. Intragastric whole milk was effective in restoring ODC induction and accumulation of its immediate product, putrescine, in response to isoproterenol administration. Glucose was shown to mediate this effect by the ability of intragastric skimmed milk, lactose, galactose, or D-glucose to return ODC induction, and the inability of casein, sucrose, fructose, L-glucose, or pyruvate plus lactate to do so. D-Glucose also reestablished ODC induction by phenylephrine and glucagon. Parenteral administration of D-glucose produced results comparable to those obtained after intragastric administration. Isoproterenol induction of ODC was prevented when hepatic glucose uptake was blocked by phlorizin but not by blockade of central nervous system glucose uptake with 2-deoxyglucose. We conclude that intrahepatic glucose is an absolute requirement for hepatic ODC induction by isoproterenol, phenylephrine, or glucagon in preweanling rats.

2006 ◽  
Vol 290 (1) ◽  
pp. E9-E16 ◽  
Author(s):  
Catherine A. DiCostanzo ◽  
Dominique P. Dardevet ◽  
Doss W. Neal ◽  
Margaret Lautz ◽  
Eric Allen ◽  
...  

Portal glucose delivery enhances net hepatic glucose uptake (NHGU) relative to peripheral glucose delivery. We hypothesize that the sympathetic nervous system normally restrains NHGU, and portal glucose delivery relieves the inhibition. Two groups of 42-h-fasted conscious dogs were studied using arteriovenous difference techniques. Denervated dogs (DEN; n = 10) underwent selective sympathetic denervation by cutting the nerves at the celiac nerve bundle near the common hepatic artery; control dogs (CON; n = 10) underwent a sham procedure. After a 140-min basal period, somatostatin was given along with basal intraportal infusions of insulin and glucagon. Glucose was infused peripherally to double the hepatic glucose load (HGL) for 90 min ( P1). In P2, glucose was infused intraportally (3–4 mg·kg−1·min−1), and the peripheral glucose infusion was reduced to maintain the HGL for 90 min. This was followed by 90 min ( P3) in which portal glucose infusion was terminated and peripheral glucose infusion was increased to maintain the HGL. P1 and P3 were averaged as the peripheral glucose infusion period (PE). The average HGLs (mg·kg−1·min−1) in CON and DEN were 55 ± 3 and 54 ± 4 in the peripheral periods and 55 ± 3 and 55 ± 4 in P2, respectively. The arterial insulin and glucagon levels remained basal in both groups. NHGU (mg·kg−1·min−1) in CON averaged 1.7 ± 0.3 during PE and increased to 2.9 ± 0.3 during P2. NHGU (mg·kg−1·min−1) was greater in DEN than CON ( P < 0.05) during PE (2.9 ± 0.4) and failed to increase significantly (3.2 ± 0.2) during P2 (not significant vs. CON). Selective sympathetic denervation increased NHGU during hyperglycemia but significantly blunted the response to portal glucose delivery.


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.


1991 ◽  
Vol 37 (Supplement) ◽  
pp. S35-S42 ◽  
Author(s):  
Ryuzo KAWAMORI ◽  
Minoru KUBOTA ◽  
Masahiko IKEDA ◽  
Munehide MATSUHISA ◽  
Masashi KUBOTA ◽  
...  

2000 ◽  
Vol 279 (6) ◽  
pp. E1271-E1277 ◽  
Author(s):  
Mary Courtney Moore ◽  
Po-Shiuan Hsieh ◽  
Doss W. Neal ◽  
Alan D. Cherrington

The glycemic and hormonal responses and net hepatic and nonhepatic glucose uptakes were quantified in conscious 42-h-fasted dogs during a 180-min infusion of glucose at 10 mg · kg−1 · min−1 via a peripheral (Pe10, n = 5) or the portal (Po10, n = 6) vein. Arterial plasma insulin concentrations were not different during the glucose infusion in Pe10 and Po10 (37 ± 6 and 43 ± 12 μU/ml, respectively), and glucagon concentrations declined similarly throughout the two studies. Arterial blood glucose concentrations during glucose infusion were not different between groups (125 ± 13 and 120 ± 6 mg/dl in Pe10 and Po10, respectively). Portal glucose delivery made the hepatic glucose load significantly greater (36 ± 3 vs. 46 ± 5 mg · kg−1 · min−1 in Pe10 vs. Po10, respectively, P < 0.05). Net hepatic glucose uptake (NHGU; 1.1 ± 0.4 vs. 3.1 ± 0.4 mg · kg−1 · min−1) and fractional extraction (0.03 ± 0.01 vs. 0.07 ± 0.01) were smaller ( P < 0.05) in Pe10 than in Po10. Nonhepatic (primarily muscle) glucose uptake was correspondingly increased in Pe10 compared with Po10 (8.9 ± 0.4 vs. 6.9 ± 0.4 mg · kg−1 · min−1, P < 0.05). Approximately one-half of the difference in NHGU between groups could be accounted for by the difference in hepatic glucose load, with the remainder attributable to the effect of the portal signal itself. Even in the absence of somatostatin and fixed hormone concentrations, the portal signal acts to alter partitioning of a glucose load among the tissues, stimulating NHGU and reducing peripheral glucose uptake.


1999 ◽  
Vol 276 (5) ◽  
pp. E930-E937 ◽  
Author(s):  
Po-Shiuan Hsieh ◽  
Mary Courtney Moore ◽  
Doss W. Neal ◽  
Maya Emshwiller ◽  
Alan D. Cherrington

Experiments were performed on two groups of 42-h-fasted conscious dogs ( n = 6/group). Somatostatin was given peripherally with insulin (4-fold basal) and glucagon (basal) intraportally. In the first experimental period, glucose was infused peripherally to double the hepatic glucose load (HGL) in both groups. In the second experimental period, glucose (21.8 μmol ⋅ kg−1⋅ min−1) was infused intraportally and the peripheral glucose infusion rate (PeGIR) was reduced to maintain the precreating HGL in the portal signal (PO) group, whereas saline was given intraportally in the control (CON) group and PeGIR was not changed. In the third period, the portal glucose infusion was stopped in the PO group and PeGIR was increased to sustain HGL. PeGIR was continued in the CON group. The glucose loads to the liver did not differ in the CON and PO groups. Net hepatic glucose uptake was 9.6 ± 2.5, 11.6 ± 2.6, and 15.5 ± 3.2 vs. 10.8 ± 1.8, 23.7 ± 3.0, and 15.5 ± 1.1 μmol ⋅ kg−1⋅ min−1, and nonhepatic glucose uptake (non-HGU) was 29.8 ± 1.1, 40.1 ± 4.5, and 49.5 ± 4.0 vs. 26.6 ± 4.3, 23.2 ± 4.0, and 40.4 ± 3.1 μmol ⋅ kg−1⋅ min−1in the CON and PO groups during the three periods, respectively. Cessation of the portal signal shifted NHGU and non-HGU to rates similar to those evident in the CON group within 10 min. These results indicate that even under hyperinsulinemic conditions the effects of the portal signal on hepatic and peripheral glucose uptake are rapidly reversible.


1991 ◽  
Vol 260 (2) ◽  
pp. E194-E202 ◽  
Author(s):  
A. Mitrakou ◽  
R. Jones ◽  
Y. Okuda ◽  
J. Pena ◽  
N. Nurjhan ◽  
...  

The present studies were undertaken to quantitate the relative contributions of the indirect and direct pathways for hepatic glycogen repletion and to determine the role of splanchnic tissues in provision of C precursors used for the indirect pathway. For this purpose, we administered oral glucose (1.4 g/kg) enriched with [1-14C]glucose to 18-h fasted dogs and measured net hepatic and net gastrointestinal glucose, lactate, and alanine balance, hepatic and gastrointestinal fractional extraction [( 3H]lactate), release and uptake of lactate, as well as the total amount of hepatic glycogen formed from the oral glucose and the 14C labeling pattern of the glycogen-glucose C. Although net hepatic glucose uptake (8.7 +/- 0.6 g, 27% of the oral load) exceeded the amount of glycogen formed from the oral glucose (6.3 +/- 1.1 g), analysis of radioactivity in C-1 of the glycogen glucose indicated that nearly 50% of the glycogen was formed by the indirect pathway. Net hepatic uptake of lactate (1.4 +/- 0.1 g) and alanine (1.5 +/- 0.1 g) could account for greater than 90% of glycogen formed by the indirect pathway if all of the lactate and alanine taken up by the liver had been incorporated into glycogen. Release of lactate and alanine by splanchnic tissues approximated the amount of lactate and alanine taken up by the liver. However, in addition to taking up lactate, the liver also produced nearly as much lactate as the gastrointestinal tract (1.8 +/- 0.2 vs. 2.0 +/- 0.3 g, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)


2000 ◽  
Vol 279 (2) ◽  
pp. E284-E292 ◽  
Author(s):  
Po-Shiuan Hsieh ◽  
Mary Courtney Moore ◽  
Doss W. Neal ◽  
Alan D. Cherrington

The aim of this study was to determine whether the elimination of the hepatic arterial-portal (A-P) venous glucose gradient would alter the effects of portal glucose delivery on hepatic or peripheral glucose uptake. Three groups of 42-h-fasted conscious dogs ( n = 7/group) were studied. After a 40-min basal period, somatostatin was infused peripherally along with intraportal insulin (7.2 pmol·kg−1·min−1) and glucagon (0.65 ng·kg−1·min−1). In test period 1 (90 min), glucose was infused into a peripheral vein to double the hepatic glucose load (HGL) in all groups. In test period 2 (90 min) of the control group (CONT), saline was infused intraportally; in the other two groups, glucose was infused intraportally (22.2 μmol·kg−1·min−1). In the second group (PD), saline was simultaneously infused into the hepatic artery; in the third group (PD+HAD), glucose was infused into the hepatic artery to eliminate the negative hepatic A-P glucose gradient. HGL was twofold basal in each test period. Net hepatic glucose uptake (NHGU) was 10.1 ± 2.2 and 12.8 ± 2.1 vs. 11.5 ± 1.6 and 23.8 ± 3.3* vs. 9.0 ± 2.4 and 13.8 ± 4.2 μmol · kg−1·min−1 in the two periods of CONT, PD, and PD+HAD, respectively (*  P < 0.05 vs. same test period in PD and PD+HAD). NHGU was 28.9 ± 1.2 and 39.5 ± 4.3 vs. 26.3 ± 3.7 and 24.5 ± 3.7* vs. 36.1 ± 3.8 and 53.3 ± 8.5 μmol·kg−1·min−1 in the first and second periods of CONT, PD, and PD+HAD, respectively (*  P < 0.05 vs. same test period in PD and PD+HAD). Thus the increment in NHGU and decrement in extrahepatic glucose uptake caused by the portal signal were significantly reduced by hepatic arterial glucose infusion. These results suggest that the hepatic arterial glucose level plays an important role in generation of the effect of portal glucose delivery on glucose uptake by liver and muscle.


2003 ◽  
Vol 284 (3) ◽  
pp. E574-E582 ◽  
Author(s):  
Christine M. Donmoyer ◽  
Sheng-Song Chen ◽  
D. Brooks Lacy ◽  
David A. Pearson ◽  
Adrian Poole ◽  
...  

Total parenteral nutrition (TPN) markedly augments net hepatic glucose uptake (NHGU) and hepatic glycolysis in the presence of mild hyperglycemia and hyperinsulinemia. This increase is impaired by an infection. We determined whether the adaptation to TPN alters the responsiveness of the liver to insulin and whether infection impairs that response. Chronically catheterized dogs received TPN for 5 days. On day 3 of TPN, either a nonlethal hypermetabolic infection was induced (INF, n = 5) or a sham surgery was performed (SHAM, n = 5). Forty-two hours after clot implantation, somatostatin and glucagon (34 ± 3 vs. 84 ± 11 pg/ml in artery, SHAM vs. INF) were infused, and a three-step (120 min each) isoglycemic (∼120 mg/dl) hyperinsulinemic (∼12, 25, and 50 μU/ml) clamp was performed to simulate levels seen in normal, infected, and exogenous insulin treatment states. In SHAM, NHGU (3.5 ± 0.2 to 4.2 ± 0.4 to 4.6 ± 0.5 mg · kg−1· min−1) modestly increased. In INF, NHGU was consistently lower at each insulin step (1.1 ± 0.5 to 2.6 ± 0.5 to 2.8 ± 0.7 mg · kg−1· min−1). Although NHGU increased from the first to the second step in INF, it did not increase further with the highest dose of insulin. Despite increases in NHGU, net hepatic lactate release did not increase in SHAM and fell in INF. In summary, in the TPN-adapted state, liver glucose uptake is unresponsive to increases in insulin above the basal level. Although the infection-induced increase in insulin sustains NHGU, further increments in insulin enhance neither NHGU nor glycolysis.


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