Glucose transport with brief dietary restriction: heterogenous responses in muscles

1994 ◽  
Vol 266 (6) ◽  
pp. E946-E952 ◽  
Author(s):  
G. D. Cartee ◽  
D. J. Dean
Keyword(s):  
Glucose Transport ◽  
Dietary Restriction ◽  
Time Course ◽  
Abdominal Fat ◽  
Transport Activity ◽  
Fischer 344 ◽  
Flexor Digitorum Brevis ◽  
Ad Libitum ◽  
Ad Libitum Intake ◽  
Flexor Digitorum

The time course (1, 5, or 20 days) for the effect of dietary restriction (DR; approximately 25% reduction below ad libitum intake) on epitrochlearis and flexor digitorum brevis (FDB) muscle glucose transport activity was studied in female Fischer 344 rats (8 mo old). Epitrochlearis glucose transport activity with 100 microU/ml insulin was increased by 38% after 5 days of DR (P < 0.05) despite no change in glucose transport activity with 0 or 20,000 microU/ml insulin. The increase with 100 microU/ml insulin was not further enhanced by 20 days of DR. DR did not result in a significant increase in the glucose transport activity of the FDB with 0, 100, or 20,000 microU/ml insulin. Abdominal fat content was significantly (P < 0.01) reduced below ad libitum levels only after 20 days of DR. These results demonstrate that DR-induced improvement in epitrochlearis glucose transport activity with a physiological insulin concentration can occur very rapidly, preceding detectable changes in basal or maximal insulin-stimulated glucose transport activity or abdominal fat pad mass, and the enhancement of insulin action does not occur simultaneously in all muscles.

Glucose transporters and glucose transport in skeletal muscles of 1- to 25-mo-old rats

1993 ◽  
Vol 264 (3) ◽  
pp. E319-E327 ◽  
Author(s):  
E. A. Gulve ◽  
E. J. Henriksen ◽  
K. J. Rodnick ◽  
J. H. Youn ◽  
J. O. Holloszy
Keyword(s):  
Glucose Transport ◽  
Skeletal Muscles ◽  
Glucose Transporter ◽  
Contractile Activity ◽  
Transport Activity ◽  
Glut 4 ◽  
Flexor Digitorum Brevis ◽  
Old Rats ◽  
Growth And Aging ◽  
Flexor Digitorum

It is widely thought that aging results in development of insulin resistance in skeletal muscle. In this study, we examined the effects of growth and aging on the concentration of the GLUT-4 glucose transporter and on glucose transport activity in skeletal muscles of female Long-Evans rats. Relative amounts of immunoreactive GLUT-4 protein were measured in muscle homogenates of 1-, 10-, and 25-mo-old rats by immunoblotting with a polyclonal antibody directed against GLUT-4. In the epitrochlearis, plantaris, and the red and white regions of the quadriceps muscles, GLUT-4 immunoreactivity decreased by 14-33% between 1 and 10 mo of age and thereafter remained constant. In flexor digitorum brevis (FDB) and soleus muscles, GLUT-4 concentration was similar at all three ages studied. Glucose transport activity was assessed in epitrochlearis and FDB muscles by incubation with 2-deoxyglucose under the following conditions: basal, submaximal insulin, and either maximal insulin or maximal insulin combined with contractile activity. Glucose transport in the epitrochlearis muscle decreased by approximately 60% between 1 and 4 mo of age and then did not decline further between 4 and 25 mo of age. Transport activity in the FDB assessed with a maximally effective insulin concentration decreased only slightly (< 20%) between 1 and 7 mo of age. Aging, i.e., the transition from young adulthood to old age, was not associated with a decrease in glucose transport activity in either the epitrochlearis or the FDB.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Histone H4 stimulates glucose transport activity in rat skeletal muscle

1993 ◽  
Vol 295 (2) ◽  
pp. 549-553 ◽  
Author(s):  
L L Louters ◽  
E J Henriksen ◽  
C M Tipton
Keyword(s):  
Glucose Transport ◽  
Specific Binding ◽  
Insulin Receptors ◽  
Complex Signal ◽  
Scatchard Analysis ◽  
Maximal Effect ◽  
Histone H4 ◽  
Transport Activity ◽  
Igf I ◽  
Flexor Digitorum Brevis

We investigated the effects of purified histone H4 on glucose transport activity in rat soleus and flexor digitorum brevis muscles. Histone H4, at concentrations up to 11.8 microM, increased 2-deoxyglucose (2-DG) uptake in a dose-dependent fashion. However, at concentrations higher than 11.8 microM, H4 caused a decrease in 2-DG uptake from the maximum, suggesting a secondary inhibitory action of this compound. The maximal effect of H4 on 2-DG uptake was not additive to the maximal effect of insulin. Moreover, 2-DG uptake in the presence of both H4 and insulin was significantly lower than the 2-DG uptake in the presence of insulin alone. The maximal effect of H4 on stimulation of 2-DG uptake was neither additive nor inhibitory to the maximal effects of the intracellularly acting insulin mimetics sodium vanadate or H2O2. It was, on the other hand, additive to the maximal effects of muscle contractions. Also, in contrast with the effects of H4 on insulin-stimulated 2-DG uptake, H4 did not inhibit insulin-like growth factor-I (IGF-I)-stimulated 2-DG uptake, as the maximal effects of H4 and IGF-I were additive. Scatchard analysis of the binding of 125I-insulin in the absence or presence of histone H4 revealed that H4 increased the specific binding of insulin without affecting receptor affinity. These data suggest that H4 interacts with the insulin, rather than the hypoxia/contraction, pathway for activation of glucose transport in muscle tissue, and that H4 acts either directly or indirectly to increase the number of insulin receptors at the surface of the muscle cell. This interaction does not appear to occur with the similar, although distinct, IGF-I receptor. These studies may provide additional insight into the complex signal-transduction systems of insulin action.

Effect of stimulation frequency on contraction-induced glucose transport in rat skeletal muscle

2000 ◽  
Vol 279 (4) ◽  
pp. E862-E867 ◽  
Author(s):  
Jacob Ihlemann ◽  
Thorkil Ploug ◽  
Ylva Hellsten ◽  
Henrik Galbo
Keyword(s):  
Metabolic Rate ◽  
Glucose Transport ◽  
Stimulation Frequency ◽  
Total Force ◽  
Glycogen Depletion ◽  
Force Development ◽  
The Face ◽  
Flexor Digitorum Brevis ◽  
Ampk Activity ◽  
Flexor Digitorum

Previous studies have indicated that frequency of stimulation is a major determinant of glucose transport in contracting muscle. We have now studied whether this is so also when total force development or metabolic rate is kept constant. Incubated soleus muscles were electrically stimulated to perform repeated tetanic contractions at four different frequencies (0.25, 0.5, 1, and 2 Hz) for 10 min. Resting length was adjusted to achieve identical total force development or metabolic rate (glycogen depletion and lactate accumulation). Overall, at constant total force development, glucose transport (2-deoxyglucose uptake) increased with stimulation frequency ( P < 0.05; basal: 25 ± 2, 0.25 Hz: 50 ± 4, 0.5 Hz: 50 ± 3, 1 Hz: 81 ± 5, 2 Hz: 79 ± 3 nmol · g−1 · 5 min−1). However, glucose transport was identical ( P > 0.05) at the two lower (0.25 and 0.5 Hz) as well as at the two higher (1 and 2 Hz) frequencies. Glycogen decreased ( P < 0.05; basal: 19 ± 1, 0.25 Hz: 13 ± 1, 0.5 Hz: 12 ± 2, 1 Hz: 7 ± 1, 2 Hz: 7 ± 1 mmol/kg) and 5′-AMP-activated protein kinase (AMPK) activity increased ( P < 0.05; basal: 1.7 ± 0.4, 0.25 Hz: 32.4 ± 7.0, 0.5 Hz: 36.5 ± 2.1, 1 Hz: 63.4 ± 8.0, 2 Hz: 67.0 ± 13.4 pmol · mg−1 · min−1) when glucose transport increased. Experiments with constant metabolic rate were carried out in soleus, flexor digitorum brevis, and epitrochlearis muscles. In all muscles, glucose transport was identical at 0.5 and 2 Hz ( P > 0.05); also, AMPK activity did not increase with stimulation frequency. In conclusion, muscle glucose transport increases with stimulation frequency but only in the face of energy depletion and increase in AMPK activity. This indicates that contraction-induced glucose transport is elicited by metabolic demands rather than by events occurring early during the excitation-contraction coupling.

Energy metabolism and aging: a lifelong study of Fischer 344 rats

1992 ◽  
Vol 263 (3) ◽  
pp. E448-E452 ◽  
Author(s):  
R. J. McCarter ◽  
J. Palmer
Keyword(s):  
Energy Metabolism ◽  
Metabolic Rate ◽  
Food Restriction ◽  
Fischer 344 Rats ◽  
Fuel Utilization ◽  
Fischer 344 ◽  
Group A ◽  
Ad Libitum ◽  
Group B ◽  
Ad Libitum Intake

Metabolic rate is widely regarded as an important component of aging processes, but variation of metabolic rate with age has not been well characterized. The purpose of the present study was to measure daily metabolic rate under usual living conditions over the lifespan of barrier-maintained Fischer 344 rats. In addition, effects of life-prolonging food restriction were assessed. Metabolic rate was measured indirectly by analysis of gas entering and leaving standard rodent cages over a 24-h period. Group A rats were fed ad libitum. Group B rats were fed 60% of ad libitum intake from 6 wk of age. Both group A and group B rats exhibited variation of metabolic rate per unit lean mass over the lifespan, with metabolic rate decreasing from 6 to 18 mo and then increasing from 18 to 24 mo of age. Results show estimates of lifetime energy expenditure in rats should take account of variability of metabolic rate and confirm the life-prolonging action of food restriction is not a consequence of reduced metabolic rate per unit metabolic mass. Rather, restricted rats are able to sustain appropriate fluxes of nutrients and appropriate metabolic rate under conditions of fuel utilization which promote maintenance of cellular homeostasis.

Adaptation of muscle glucose transport with caloric restriction in adult, middle-aged, and old rats

1994 ◽  
Vol 266 (5) ◽  
pp. R1443-R1447 ◽  
Author(s):  
G. D. Cartee ◽  
E. W. Kietzke ◽  
C. Briggs-Tung
Keyword(s):  
Caloric Restriction ◽  
Glucose Transport ◽  
Glucose Transporter ◽  
Insulin Concentration ◽  
Transporter Protein ◽  
Fischer 344 ◽  
Glucose Transport System ◽  
Old Rats ◽  
Ad Libitum Intake ◽  
Muscle Glucose Transport

The effects of prolonged caloric restriction (60% of ad libitum intake initiated at 14 wk of age) on glucose transport activity in isolated epitrochlearis muscles were studied in female Fischer 344 rats aged 8, 18, and 23 mo. Basal 3-O-methylglucose transport (3-MG) rate (without insulin) was not significantly altered by caloric restriction. With a submaximally effective insulin concentration (75 microU/ml), 3-MG transport was enhanced in the caloric-restricted groups by 59, 59, and 105% at 8, 18, and 23 mo of age, respectively. With a maximally effective insulin concentration (20,000 microU/ml), 3-MG transport was increased after caloric restriction, despite no change in muscle GLUT4 glucose transporter protein content. These results indicate that chronic caloric restriction enhances insulin stimulation of the glucose transport system independent of changes in basal glucose transport or muscle GLUT4 levels, and insulin-stimulated glucose transport is enhanced in rats with chronic caloric restriction at least until 23 mo of age.

scholarly journals Determination of the rates of appearance and loss of glucose transporters at the cell surface of rat adipose cells

1991 ◽  
Vol 278 (1) ◽  
pp. 235-241 ◽  
Author(s):  
A E Clark ◽  
G D Holman ◽  
I J Kozka
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Glucose Transport ◽  
Time Course ◽  
Transport Activity ◽  
Insulin Stimulation ◽  
Surface Labelling ◽  
Lag Period ◽  
Adipose Cells ◽  
Stimulation Of

We have used an impermeant bis-mannose compound (2-N-[4-(1-azi-2,2,2-trifluoroethyl)benzoyl]-1,3-bis-(D-mannos+ ++- 4-yloxy)-2- propylamine; ATB-BMPA) to photolabel the glucose transporter isoforms GLUT4 and GLUT1 that are present in rat adipose cells. Plasma-membrane fractions and light-microsome membrane fractions were both labelled by ATB-BMPA. The labelling of GLUT4 in the plasma membrane fraction from insulin-treated cells was approximately 3-fold higher than that of basal cells and corresponded with a decrease in the labelling of the light-microsome fraction. In contrast with this, the cell-surface labelling of GLUT4 from insulin-treated intact adipose cells was increased approximately 15-fold above basal levels. In these adipose cell preparations, insulin stimulated glucose transport activity approximately 30-fold. Thus the cell-surface labelling, but not the labelling of membrane fractions, closely corresponded with the stimulation of transport. The remaining discrepancy may be due to an approx. 2-fold activation of GLUT4 intrinsic transport activity. We have studied the kinetics of trafficking of transporters and found the following. (1) Lowering the temperature to 18 degrees C increased basal glucose transport and levels of cell-surface glucose transporters by approximately 3-fold. This net increase in transporters probably occurs because the process of recruitment of transporters is less temperature-sensitive than the process involved in internalization of cell-surface transporters. (2) The time course for insulin stimulation of glucose transport activity occurred with a slight lag period of 47 s and a t 1/2 3.2 min. The time course of GLUT4 and GLUT1 appearance at the cell surface showed no lag and a t 1/2 of approximately 2.3 min for both isoforms. Thus at early times after insulin stimulation there was a discrepancy between transporter abundance and transport activity. The lag period in the stimulation of transport activity may represent the time required for the approximately 2-fold stimulation of transporter intrinsic activity. (3) The decrease in transport activity after insulin removal occurred with a very high activation energy of 159 kJ.mol-1. There was thus no significant decrease in transport or less of cell-surface transporters over 60 min at 18 degrees C. The decrease in transport activity occurred with a t1/2 of 9-11 min at 37 degrees C.(ABSTRACT TRUNCATED AT 400 WORDS)

Disruption of microtubules in rat skeletal muscle does not inhibit insulin- or contraction-stimulated glucose transport

2003 ◽  
Vol 285 (4) ◽  
pp. E836-E844 ◽  
Author(s):  
Hua Ai ◽  
Evelyn Ralston ◽  
Hans P. M. M. Lauritzen ◽  
Henrik Galbo ◽  
Thorkil Ploug
Keyword(s):  
Skeletal Muscle ◽  
Glucose Transport ◽  
Immunofluorescence Microscopy ◽  
Fiber Type ◽  
Force Production ◽  
Rat Skeletal Muscle ◽  
Microtubule Network ◽  
Type Composition ◽  
Flexor Digitorum Brevis ◽  
Flexor Digitorum

Insulin and muscle contractions stimulate glucose transport in skeletal muscle through a translocation of intracellular GLUT4 glucose transporters to the cell surface. Judged by immunofluorescence microscopy, part of the GLUT4 storage sites is associated with the extensive microtubule cytoskeleton found in all muscle fibers. Here, we test whether microtubules are required mediators of the effect of insulin and contractions. In three different incubated rat muscles with distinct fiber type composition, depolymerization of microtubules with colchicine for ≤8 h did not inhibit insulin- or contraction-stimulated 2-deoxyglucose transport or force production. On the contrary, colchicine at least partially prevented the ∼30% decrease in insulin-stimulated transport that specifically developed during 8 h of incubation in soleus muscle but not in flexor digitorum brevis or epitrochlearis muscles. In contrast, nocodazole, another microtubule-disrupting drug, rapidly and dose dependently blocked insulin- and contraction-stimulated glucose transport. A similar discrepancy between colchicine and nocodazole was also found in their ability to block glucose transport in muscle giant “ghost” vesicles. This suggests that the ability of insulin and contractions to stimulate glucose transport in muscle does not require an intact microtubule network and that nocodazole inhibits glucose transport independently of its microtubule-disrupting effect.

Effect of fiber type and nutritional state on AICAR- and contraction-stimulated glucose transport in rat muscle

2002 ◽  
Vol 282 (6) ◽  
pp. E1291-E1300 ◽  
Author(s):  
Hua Ai ◽  
Jacob Ihlemann ◽  
Ylva Hellsten ◽  
Hans P. M. M. Lauritzen ◽  
D. Grahame Hardie ◽  
...  
Keyword(s):  
Glucose Transport ◽  
Fiber Type ◽  
Nutritional State ◽  
Fiber Types ◽  
Type Composition ◽  
Flexor Digitorum Brevis ◽  
Ampk Activity ◽  
Flexor Digitorum ◽  
Amp Activated Protein Kinase ◽  
Fasted Rats

AMP-activated protein kinase (AMPK) may mediate the stimulatory effect of contraction and 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) on glucose transport in skeletal muscle. In muscles with different fiber type composition from fasted rats, AICAR increased 2-deoxyglucose transport and total AMPK activity approximately twofold in epitrochlearis (EPI), less in flexor digitorum brevis, and not at all in soleus muscles. Contraction increased both transport and AMPK activity more than AICAR did. In EPI muscles, the effects of AICAR and contractions on glucose transport were partially additive despite a lower AMPK activity with AICAR compared with contraction alone. In EPI from fed rats, glucose transport responses were smaller than what was seen in fasted rats, and AICAR did not increase transport despite an increase in AMPK activity. AICAR and contraction activated both α1- and α2-isoforms of AMPK. Expression of both isoforms varied with fiber types, and α2 was highly expressed in nuclei. In conclusion, AICAR-stimulated glucose transport varies with muscle fiber type and nutritional state. AMPK is unlikely to be the sole mediator of contraction-stimulated glucose transport.

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