Control of glucose transport in adipose tissue of the rat: Role of insulin, ATP, and intracellular metabolites

1978 ◽  
Vol 56 (7) ◽  
pp. 708-712 ◽  
Author(s):  
Mitchell L. Halperin ◽  
Marina L. Mak ◽  
Wayne M. Taylor
Keyword(s):  
Adipose Tissue ◽  
Glucose Uptake ◽  
Glucose Transport ◽  
Maximum Velocity ◽  
Pentose Phosphate ◽  
Maximal Velocity ◽  
Rate Limiting ◽  
Phenazine Methosulphate ◽  
Intracellular Glucose

The purpose of this study was to elucidate some of the mechanisms of control of the glucose transport step in adipose tissue. Glucose transport was studied by monitoring the conversion of [1-14C]glucose to 14CO2 in a system where glucose transport was made rate limiting by increasing the flux through the pentose phosphate pathway with phenazine methosulphate, an agent which results in rapid rates of reoxidation of NADPH. The maximum velocity for the apparent rate of glucose transport was increased significantly by insulin. There was no change in the glucose concentration required for half-maximal rates of 14CO2 production. Glucose transport was also monitored by directly measuring the rate of glucose uptake. Glucose uptake was increased by phenazine methosulphate. The intracellular glucose-6-phosphate concentration was decreased by phenazine methosulphate. These two agents, insulin and phenazine methosulphate, seemed to act by independent mechanisms as their optimal effects on glucose uptake were additive.The apparent rate of glucose transport was decreased by ATP which resulted in a decrease in maximal velocity but did not affect the affinity for glucose. This effect of ATP was seen in the presence or absence of insulin.

THE EFFECT OF INSULIN ON HUMAN ADIPOSE TISSUE

1964 ◽  
Vol 42 (11) ◽  
pp. 1623-1635 ◽  
Author(s):  
A. Kahlenberg ◽  
N. Kalant
Keyword(s):  
Serum Albumin ◽  
Glucose Uptake ◽  
Glucose Transport ◽  
Glucose Utilization ◽  
Fatty Acid Content ◽  
Diabetic Patients ◽  
Fat Pad ◽  
Glucose Content ◽  
Rate Limiting ◽  
Intracellular Glucose

The effects of insulin on glucose transport and dissimilation have been studied in the rat fat pad and in human omentum. Intracellular glucose could not be demonstrated in the non-diabetic rat fat pad, with or without insulin. Slices of omentum, obtained during surgery from diabetic and non-diabetic patients, were incubated in a bicarbonate medium with a glucose concentration of 5.6 mM. Omentum from non-diabetic patients had intracellular glucose while diabetic tissue had none. Diabetic tissue had a significantly lower glucose uptake. In both, insulin stimulated glucose uptake in inverse relation to the basal uptake; but for comparable basal uptakes, the response to insulin was decreased in diabetic tissue. Glucose phosphorylation in omental tissue from non-diabetic humans had an apparent Km of 1.10 m M and a Vmax of 1.44 mg/g hour.Insulin (0.1 units/ml), bovine or human serum albumin, or a combination of insulin and bovine albumin, each increased glucose utilization by slices of non-diabetic omentum without affecting the intracellular glucose content or the free fatty acid content. In omental homogenates (cell-free), insulin and bovine serum albumin each increased the glucose utilization. In the presence of albumin, insulin increased the utilization only after the addition of glucose-6-phosphate dehydrogenase and phosphohexose isomerase in amounts sufficient to establish that hexokinase was rate-limiting for glucose utilization.It is concluded that (A) in diabetic human omentum and in normal rat fat pad, transport is rate-limiting in glucose utilization; (B) insulin and albumin each stimulate both transport and phosphorylation in human omentum; (C) in human diabetes, the glucose transport process of omentum has a decreased basal rate and a decreased responsiveness to insulin.

THE UPTAKE OF GLUCOSE INTO CELLS AND THE ROLE OF INSULIN IN GLUCOSE TRANSPORT

1964 ◽  
Vol 42 (6) ◽  
pp. 933-944 ◽  
Author(s):  
Margaret J. Henderson
Keyword(s):  
Cell Membrane ◽  
Glucose Uptake ◽  
Glucose Transport ◽  
Glucose Levels ◽  
Insulin Transport ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Extracellular Glucose ◽  
Rate Limiting

This presentation has been restricted to the role of insulin in glucose transport in muscle cells and deals mainly with experiments using the perfused rat heart. The several possible means for glucose transfer into cells, diffusion, pores, pinocytosis, carriers, and dimerization, have been discussed; and arguments in favor of the carrier theory, namely, specificity, kinetics, inhibition, competition, and counterflow, have been elaborated. Glucose uptake has been considered to consist of three sequential steps: (1) passage of glucose from within the capillary to the cell surface, (2) transport across the cell membrane, and (3) metabolism of glucose within the cell. The first is considered to take place by diffusion and not to be significantly limiting under normal conditions, nor to be influenced by insulin. Transport across the cell membrane is thought to be mainly under the control of insulin and is the major rate-limiting step in glucose uptake when the extracellular glucose levels are in the normal range. Metabolism of glucose within the cell is the major rate-limiting step in glucose uptake when intracellular glucose concentration is so high that its phosphorylation is near saturation.

Stimulation of glucose transport in rat adipocytes by calcium

1979 ◽  
Vol 57 (6) ◽  
pp. 692-699 ◽  
Author(s):  
Wayne M. Taylor ◽  
Lena Hau ◽  
Mitchell L. Halperin
Keyword(s):  
Glucose Transport ◽  
Maximum Velocity ◽  
Pentose Phosphate ◽  
Calcium Flux ◽  
Intracellular Camp ◽  
Rat Adipocytes ◽  
Phosphorylation Mechanism ◽  
Rate Limiting ◽  
Camp Levels ◽  
Stimulation Of

Glucose transport in rat adipocytes was studied by monitoring the conversion of [1-14C]-glucose to 14CO2 in a system where glucose transport was made rate-limiting by increasing the flux through the pentose phosphate pathway with phenazine methosulphate, an agent which rapidly reoxidizes NADPH. Calcium increased both basal and insulin-stimulated apparent rates of glucose transport by approximately 40%. The maximum velocity of the apparent rate of glucose transport was increased by extracellular calcium both in the presence or absence of insulin. There was no change in the glucose concentration required for half-maximal rates of 14CO2 production. Calcium also enhanced the stimulation of apparent rates of glucose transport by insulin when examined over a range of hormone concentrations. Adipocyte cAMP concentrations were significantly lowered by calcium under conditions which led to increased apparent rates of glucose transport. In contrast, cobalt and nickel, antagonists of calcium action, elevated adipocyte cAMP levels and inhibited apparent rates of glucose transport. Agents which inhibit transmembrane calcium flux (verapamil, tetracaine, and procaine) inhibited apparent rates of glucose transport despite a reduction in adipocyte cAMP concentration.On the basis of the above data we suggest that calcium may increase apparent rates of glucose transport in rat adipocytes both by lowering intracellular cAMP concentration and by a further mechanism independent of changes in the level of cAMP. These results are consistent with the hypothesis that glucose transport in rat adipocytes may be controlled, in part, by a cAMP-induced phosphorylation mechanism.

Glucose transport rate and glycogen synthase activity both limit skeletal muscle glycogen accumulation

2002 ◽  
Vol 282 (6) ◽  
pp. E1214-E1221 ◽  
Author(s):  
Jonathan S. Fisher ◽  
Lorraine A. Nolte ◽  
Kentaro Kawanaka ◽  
Dong-Ho Han ◽  
Terry E. Jones ◽  
...  
Keyword(s):  
Glucose Transport ◽  
Muscle Glycogen ◽  
Glycogen Synthase ◽  
Transport Rate ◽  
Prolonged Incubation ◽  
Glycogen Accumulation ◽  
Gf 109203X ◽  
Rate Limiting ◽  
Glycogen Synthase Activity

We varied rates of glucose transport and glycogen synthase I (GS-I) activity (%GS-I) in isolated rat epitrochlearis muscle to examine the role of each process in determining the rate of glycogen accumulation. %GS-I was maintained at or above the fasting basal range during 3 h of incubation with 36 mM glucose and 60 μU/ml insulin. Lithium (2 mM LiCl) added to insulin increased glucose transport rate and muscle glycogen content compared with insulin alone. The glycogen synthase kinase-3β inhibitor GF-109203x (GF; 10 μM) maintained %GS-I about twofold higher than insulin with or without lithium but did not increase glycogen accumulation. When %GS-I was lowered below the fasting range by prolonged incubation with 36 mM glucose and 2 mU/ml insulin, raising rates of glucose transport with bpV(phen) or of %GS-I with GF produced additive increases in glycogen concentration. Phosphorylase activity was unaffected by GF or bpV(phen). In muscles of fed animals, %GS-I was ∼30% lower than in those of fasted rats, and insulin-stimulated glycogen accumulation did not occur unless %GS-I was raised with GF. We conclude that the rate of glucose transport is rate limiting for glycogen accumulation unless %GS-I is below the fasting range, in which case both glucose transport rate and GS activity can limit glycogen accumulation.

scholarly journals Glucose Uptake in Trichoderma harzianum: Role of gtt1

2003 ◽  
Vol 2 (4) ◽  
pp. 708-717 ◽  
Author(s):  
Jesús Delgado-Jarana ◽  
Miguel Ángel Moreno-Mateos ◽  
Tahía Benítez
Keyword(s):  
Gene Expression ◽  
Glucose Uptake ◽  
Glucose Transport ◽  
Trichoderma Harzianum ◽  
Glucose Transporter ◽  
Biochemical Characterization ◽  
Carbon Sources ◽  
Low Carbon ◽  
Filamentous Ascomycete

ABSTRACT Using a differential display technique, the gene gtt1, which codes for a high-affinity glucose transporter, has been cloned from the mycoparasite fungus Trichoderma harzianum CECT 2413. The deduced protein sequence of the gtt1 gene shows the 12 transmembrane domains typical of sugar transporters, together with certain residues involved in glucose uptake, such as a conserved arginine between domains IV and V and an aromatic residue (Phe) in the sequence of domain X. The gtt1 gene is transcriptionally regulated, being repressed at high levels of glucose. When carbon sources other than glucose are utilized, gtt1 repression is partially alleviated. Full derepression of gtt1 is obtained when the fungus is grown in the presence of low carbon source concentrations. This regulation pattern correlates with the role of this gene in glucose uptake during carbon starvation. Gene expression is also controlled by pH, so that the gtt1 gene is repressed at pH 6 but not at pH 3, a fact which represents a novel aspect of the influence of pH on the gene expression of transporters. pH also affects glucose transport, since a strongly acidic pH provokes a 40% decrease in glucose transport velocity. Biochemical characterization of the transport shows a very low Km value for glucose (12 μM). A transformant strain that overexpresses the gtt1 gene shows a threefold increase in glucose but not galactose or xylose uptake, a finding which confirms the role of the gtt1 gene in glucose transport. The cloning of the first filamentous ascomycete glucose transporter is the first step in elucidating the mechanisms of glucose uptake and carbon repression in aerobic fungi.

scholarly journals Role of facilitative glucose uptake in the glucose-inorganic phosphate-mediated retardation and inhibition of development in different strains of mouse embryos

Reproduction ◽  
2002 ◽  
pp. 691-700 ◽  
Author(s):  
L Scott ◽  
DG Whittingham
Keyword(s):  
Glucose Uptake ◽  
Glucose Transport ◽  
Inorganic Phosphate ◽  
Mouse Embryos ◽  
Concentration Gradients ◽  
Morula Stage ◽  
Different Strains ◽  
Hybrid Development

Mouse embryos from different strains develop differently in vitro depending on the composition of the culture medium, and in particular on the presence or absence of glucose and inorganic phosphate. Glucose is both stimulatory and inhibitory in certain conditions. Glucose uptake by cells can be passive, down concentration gradients, or active, through sodium driven pumps, or can occur through facilitative transport. This study investigated the effects of inhibition of facilitative glucose transport on the glucose-inorganic phosphate-mediated blocks in development in three different strains of mouse embryo, CF-1, CD-1 and an F2 hybrid. Development of CF-1 and CD-1 embryos is blocked in medium containing glucose and inorganic phosphate but not in medium containing glucose alone, and F2 embryos are not affected. Inhibition of facilitated glucose transport to the eight-cell-morula stage in CF-1 and CD-1 embryos resulted in development in medium containing both glucose and inorganic phosphate, indicating that the prevention of facilitative glucose uptake can overcome the developmental block. Removal of inhibition before the eight-cell-morula stage resulted in total arrest of CF-1 embryos and minimum development of CD-1 embryos. F2 embryos are not affected by inorganic phosphate and glucose and showed no response to the transporter inhibitor at any stage. These data support the contention that facilitated glucose transport is active in embryos, is phosphate-dependent and that its inhibition can overcome the glucose-inorganic phosphate-mediated developmental blocks in mouse embryos.

Specific adaptations in muscle and adipose tissue in response to chronic systemic glucose oversupply in rats

1997 ◽  
Vol 273 (1) ◽  
pp. E1-E9 ◽  
Author(s):  
D. R. Laybutt ◽  
D. J. Chisholm ◽  
E. W. Kraegen
Keyword(s):  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
Glucose Uptake ◽  
Glucose Infusion ◽  
Whole Body ◽  
Glucose Disposal ◽  
Saline Control ◽  
Slow Increase ◽  
Glucose Clearance

Rats minimize hyperglycemia during chronic glucose infusion, but the metabolic processes are unclear. We investigated the tissues involved and the role of altered insulin sensitivity. Cannulated rats were infused with glucose (40 mg.kg-1.min-1) for 1 or 4 days or with saline (control). Hyperglycemia at 1 day (15.3 +/- 1.0 mM) was absent at 4 days (7.5 +/- 0.3 mM), but hyperinsulinemia persisted. Whole body glucose disposal was similarly elevated at 1 and 4 days, implying increased glucose clearance at 4 days (2-fold, P < 0.001). Muscle glucose uptake and glycogen content declined in glucose-infused rats from 1 to 4 days, whereas white adipose tissue (WAT) glucose uptake (6-fold, P < 0.001) and lipogenesis (3-fold, P < 0.001) increased. Muscle and liver triglyceride were doubled at both 1 and 4 days (P < 0.05 vs. control). Insulin sensitivity (assessed during euglycemic clamps) decreased in muscle to 34% of control at 1 and 4 days (P < 0.001 vs. control) and increased fivefold in WAT from 1 to 4 days (P < 0.05). Thus chronic glucose infusion results in a slow increase in efficiency of glucose clearance with enhanced WAT glucose uptake, lipogenesis, and insulin action. In contrast, the adaptation reduces glucose oversupply to muscle. Muscle shows sustained insulin resistance, with lipid accumulation a possible contributing factor.

Enhanced glucose transport in response to inhibition of respiration in Clone 9 cells

1989 ◽  
Vol 257 (1) ◽  
pp. C19-C28 ◽  
Author(s):  
C. L. Mercado ◽  
J. N. Loeb ◽  
F. Ismail-Beigi
Keyword(s):  
Glucose Transport ◽  
Lactate Production ◽  
Atp Synthesis ◽  
Fold Increase ◽  
Time Dependent ◽  
Maximal Velocity ◽  
Partial Recovery ◽  
Central Importance ◽  
Parallel Increase ◽  
Rate Limiting

An acceleration of ATP synthesis by anaerobic glycolysis provides important compensation for interference with respiration in a variety of cells. Effective compensation for an inhibition of respiration, however, can occur in cells in which glucose entry is rate limiting only if sufficient glucose becomes available through an enhancement of transport. We present here a detailed study of the effects of inhibition of respiration in Clone 9 cells, a continuous cell line characterized by low internal glucose concentrations (less than 10% that of the external medium) and minimal stores of glycogen. Exposure of these cells to 5 mM cyanide results in a 90% fall in cell ATP and a twofold rise in cell Na+ within 20 min. By the end of 1 h, however, there is a 4.5- to 7-fold increase in cytochalasin B-inhibitable glucose transport that is accompanied by a parallel increase in the rate of lactate production, a partial recovery of cell ATP, and no further rise in cell Na+. The acute fall in ATP resulting from a submaximally effective concentration of cyanide (0.5 mM) is moreover followed by a time-dependent recovery of cell ATP to near-normal levels and subsequent resistance to challenge with even 5 mM cyanide. The stimulation of facilitative glucose transport resulting from exposure to cyanide is attributable to an increase in maximal velocity rather than to a change in Km and persists for more than 2 h after removal of the inhibitor. These results demonstrate that, in these cells characterized by low internal glucose concentrations, regulation of glucose entry is of central importance in ATP homeostasis and that a major component of the adaptive response to an inhibition of respiration is a time-dependent increase in glucose transport.

scholarly journals Coupled Glucose Transport and Metabolism in Cultured Neuronal Cells: Determination of the Rate-Limiting Step

1995 ◽  
Vol 15 (5) ◽  
pp. 814-826 ◽  
Author(s):  
Richard R. Whitesell ◽  
Michael Ward ◽  
Anthony L. McCall ◽  
Daryl K. Granner ◽  
James M. May
Keyword(s):  
Glucose Transport ◽  
Glucose Utilization ◽  
Neuroblastoma Cell ◽  
Neuronal Cells ◽  
Neuronal Cell ◽  
Cell Types ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Rate Limiting ◽  
Intracellular Glucose

In brain and nerves the phosphorylation of glucose, rather than its transport, is generally considered the major rate-limiting step in metabolism. Since little is known regarding the kinetic coupling between these processes in neuronal tissues, we investigated the transport and phosphorylation of [2-3H]glucose in two neuronal cell models: a stable neuroblastoma cell line (NCB20), and a primary culture of isolated rat dorsal root ganglia cells. When transport and phosphorylation were measured in series, phosphorylation was the limiting step, because intracellular glucose concentrations were the same as those outside of cells, and because the apparent Km for glucose utilization was lower than expected for the transport step. However, the apparent Km was still severalfold higher than the Km of hexokinase I. When [2-3H]glucose efflux and phosphorylation were measured from the same intracellular glucose pool in a parallel assay, rates of glucose efflux were three- to-fivefold greater than rates of phosphorylation. With the parallel assay, we observed that activation of glucose utilization by the sodium channel blocker veratridine caused a selective increase in glucose phosphorylation and was without effect on glucose transport. In contrast to results with glucose, both cell types accumulated 2-deoxy-d-[14C]glucose to concentrations severalfold greater than extracellular concentrations. We conclude from these studies that glucose utilization in neuronal cells is phosphorylation-limited, and that the coupling between transport and phosphorylation depends on the type of hexose used.

scholarly journals Huntingtin-associated protein 1 plays an essential role in the pathogenesis of type 2 diabetes by regulating the translocation of GLUT4 in mouse adipocytes

2020 ◽  
Vol 8 (1) ◽  
pp. e001199
Author(s):  
Yan-Ju Gong ◽  
Ying Feng ◽  
Yuan-Yuan Cao ◽  
Jia Zhao ◽  
Wei Wu ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Body Weight ◽  
Adipose Tissue ◽  
Glucose Uptake ◽  
Hek293 Cells ◽  
Diabetic Mice ◽  
Glut4 Translocation ◽  
Mouse Adipocytes

ObjectiveGlucose disposal by insulin-responsive tissues maintains the body glucose homeostasis and insulin resistance leads to a risk of developing type 2 diabetes (T2DM). Insulin stimulates the translocation of glucose transporter isoform 4 (GLUT4) vesicles from intracellular compartments to the plasma membrane to facilitate glucose uptake. However, the underlying mechanisms of GLUT4 vesicle translocation are not well defined. Here we show the role of huntingtin-associated protein 1 (HAP1) in GLUT4 translocation in adipocytes and the pathogenesis of T2DM.Research design and methodsThe parameters for glucose metabolism including body weight, glucose tolerance and insulin tolerance were assessed in wild-type (WT) and Hap1+/- mice. HAP1 protein expression was verified in adipose tissue. Hap1 mRNA and protein expression was monitored in adipose tissue of high-fat diet (HFD)-induced diabetic mice. Insulin-stimulated GLUT4 vesicle translocation and glucose uptake were detected using immunofluorescence techniques and quantified in primary adipocytes from Hap1-/- mice. The interaction between HAP1 and GLUT4 was assessed by immunofluorescence colocalization and co-immunoprecipitation in HEK293 cells and adipose tissue. The role of sortilin in HAP1 and GLUT4 interaction was approved by co-immunoprecipitation and RNA interference.ResultsThe expression of Hap1 mRNA and protein was detected in WT mouse adipose tissue and downregulated in adipose tissue of HFD-induced diabetic mice. Hap1+/- mice exhibited increased body weight, pronounced glucose tolerance and significant insulin intolerance compared with the WT mice. HAP1 colocalized with GLUT4 in mouse adipocytes and cotransfected HEK293 cells. Furthermore, the insulin-stimulated GLUT4 vesicle translocation and glucose uptake were defective in Hap1-/- adipocytes. Finally, sortilin mediated the interaction of HAP1 and GLUT4.ConclusionsOur study showed that HAP1 formed a protein complex with GLUT4 and sortilin, and played a critical role in insulin-stimulated GLUT4 translocation in adipocytes. Its downregulation may contribute to the pathogenesis of diabetes.

Sign in / Sign up

Export Citation Format

Share Document