Effects of exercise training on skeletal muscle glucose uptake and transport

1993 ◽  
Vol 264 (3) ◽  
pp. C727-C733 ◽  
Author(s):  
G. J. Etgen ◽  
J. T. Brozinick ◽  
H. Y. Kang ◽  
J. L. Ivy

Exercise training increases the concentration of GLUT-4 protein in skeletal muscle that is associated with an increase in maximal insulin-stimulated glucose transport. The purpose of this study was to determine whether exercise training results in a long-lasting increase in insulin-stimulated glucose transport in rat skeletal muscle. Glucose uptake and skeletal muscle 3-O-methyl-D-glucose (3-MG) transport were determined during hindlimb perfusion in the presence of a maximally stimulating concentration of insulin (10 mU/ml). Hindlimb glucose uptake was approximately 29% above sedentary (Sed) levels in rats examined within 24 h (24H) of their last exercise session. However, when rats were examined 48 h (48H) after their last exercise session, hindlimb glucose uptake was not different from Sed levels. Maximal 3-MG transport was enhanced, above Sed levels, in red (RG; 72% increase) and white (WG; 44% increase) gastrocnemius and plantaris (Plan; 67% increase) muscles, but not soleus (Sol), of 24H rats. GLUT-4 protein content was significantly elevated in those muscles that exhibited enhanced 3-MG transport in 24H rats. GLUT-4 protein content was also elevated in RG, WG, and Plan of 48H rats and was not different from 24H rats. Despite the elevated GLUT-4 protein content, 3-MG transport in 48H rats was only slightly, although statistically not significantly, higher than in Sed rats. These results provide evidence that exercise training does not result in a persistent increase in skeletal muscle glucose uptake or transport, despite an increase in GLUT-4 protein content.

1997 ◽  
Vol 83 (6) ◽  
pp. 2043-2047 ◽  
Author(s):  
Kentaro Kawanaka ◽  
Izumi Tabata ◽  
Shigeru Katsuta ◽  
Mitsuru Higuchi

Kawanaka, Kentaro, Izumi Tabata, Shigeru Katsuta, and Mitsuru Higuchi. Changes in insulin-stimulated glucose transport and GLUT-4 protein in rat skeletal muscle after training. J. Appl. Physiol. 83(6): 2043–2047, 1997.—After running training, which increased GLUT-4 protein content in rat skeletal muscle by <40% compared with control rats, the training effect on insulin-stimulated maximal glucose transport (insulin responsiveness) in skeletal muscle was short lived (24 h). A recent study reported that GLUT-4 protein content in rat epitrochlearis muscle increased dramatically (∼2-fold) after swimming training (J.-M. Ren, C. F. Semenkovich, E. A. Gulve, J. Gao, and J. O. Holloszy. J. Biol. Chem. 269, 14396–14401, 1994). Because GLUT-4 protein content is known to be closely related to skeletal muscle insulin responsiveness, we thought it possible that the training effect on insulin responsiveness may remain for >24 h after swimming training if GLUT-4 protein content decreases gradually from the relatively high level and still remains higher than control level for >24 h after swimming training. Therefore, we examined this possibility. Male Sprague-Dawley rats swam 2 h a day for 5 days with a weight equal to 2% of body mass. Approximately 18, 42, and 90 h after cessation of training, GLUT-4 protein concentration and 2-[1,2-3H]deoxy-d-glucose transport in the presence of a maximally stimulating concentration of insulin (2 mU/ml) were examined by using incubated epitrochlearis muscle preparation. Swimming training increased GLUT-4 protein concentration and insulin responsiveness by 87 and 85%, respectively, relative to age-matched controls when examined 18 h after training. Forty-two hours after training, GLUT-4 protein concentration and insulin responsiveness were still higher by 52 and 51%, respectively, in muscle from trained rats compared with control. GLUT-4 protein concentration and insulin responsiveness in trained muscle returned to sedentary control level within 90 h after training. We conclude that 1) the change in insulin responsiveness during detraining is directly related to muscle GLUT-4 protein content, and 2) consequently, the greater the increase in GLUT-4 protein content that is induced by training, the longer an effect on insulin responsiveness persists after the training.


1997 ◽  
Vol 272 (5) ◽  
pp. C1734-C1738 ◽  
Author(s):  
S. Kristiansen ◽  
J. Jones ◽  
A. Handberg ◽  
G. L. Dohm ◽  
E. A. Richter

We have recently shown that eccentric contractions (ECs; forced lengthening of active muscle) elicit a delayed decrease in glucose transporter (GLUT-4) protein content in rat skeletal muscle and a decrease in subsequent contraction-stimulated glucose transport. Here, we investigate whether this decrease in total GLUT-4 protein after prior ECs is due to changes in GLUT-4 gene transcription rate and GLUT-4 mRNA level. Furthermore, the effect of prior ECs on sarcolemmal GLUT-4 protein content in plasma membrane (PM) vesicles isolated from contraction-stimulated muscle was determined. Rat gastrocnemius muscle was electrically stimulated for ECs, and the contralateral muscle served, as unstimulated control (UC). Two days later, the total GLUT-4 protein content was decreased by 50% (P < 0.05) and 32% (P < 0.05) in the white and red gastrocnemius muscle, respectively. Furthermore, the GLUT-4 mRNA concentration was decreased by 41% (P < 0.05) in both the white and red gastrocnemius muscle. Moreover, the GLUT-4 transcription rate, determined by nuclear run-on analysis, was decreased by 75% (P < 0.05) in mixed EC gastrocnemius muscle compared with UC muscle. PM vesicles were isolated from EC and UC muscle after 15 min of isometric contractions. The PM GLUT-4 protein content was reduced by 51% (P < 0.05) in EC muscle compared with UC muscle. In conclusion, 2 days after ECs, the GLUT-4 transcription rate, GLUT-4 mRNA, and GLUT-4 protein content were decreased in rat skeletal muscle. Moreover, the PM GLUT-4 protein content in contraction-stimulated muscle was decreased. We suggest that eccentric muscle contractions decrease muscle GLUT-4 transcription rate, resulting in a lower GLUT-4 protein content, which in turn decreases the number of GLUT-4 transporters translocated to the sarcolemma, ultimately leading to decreased contraction-induced muscle glucose transport.


2001 ◽  
Vol 90 (6) ◽  
pp. 2019-2024 ◽  
Author(s):  
Shin Terada ◽  
Toshiko Yokozeki ◽  
Kentaro Kawanaka ◽  
Kishiko Ogawa ◽  
Mitsuru Higuchi ◽  
...  

This study was performed to assess the effects of short-term, extremely high-intensity intermittent exercise training on the GLUT-4 content of rat skeletal muscle. Three- to four-week-old male Sprague-Dawley rats with an initial body weight ranging from 45 to 55 g were used for this study. These rats were randomly assigned to an 8-day period of high-intensity intermittent exercise training (HIT), relatively high-intensity intermittent prolonged exercise training (RHT), or low-intensity prolonged exercise training (LIT). Age-matched sedentary rats were used as a control. In the HIT group, the rats repeated fourteen 20-s swimming bouts with a weight equivalent to 14, 15, and 16% of body weight for the first 2, the next 4, and the last 2 days, respectively. Between exercise bouts, a 10-s pause was allowed. RHT consisted of five 17-min swimming bouts with a 3-min rest between bouts. During the first bout, the rat swam without weight, whereas during the following four bouts, the rat was attached to a weight equivalent to 4 and 5% of its body weight for the first 5 days and the following 3 days, respectively. Rats in the LIT group swam 6 h/day for 8 days in two 3-h bouts separated by 45 min of rest. In the first experiment, the HIT, LIT, and control rats were compared. GLUT-4 content in the epitrochlearis muscle in the HIT and LIT groups after training was significantly higher than that in the control rats by 83 and 91%, respectively. Furthermore, glucose transport activity, stimulated maximally by both insulin (2 mU/ml) (HIT: 48%, LIT: 75%) and contractions (25 10-s tetani) (HIT: 55%, LIT: 69%), was higher in the training groups than in the control rats. However, no significant differences in GLUT-4 content or in maximal glucose transport activity in response to both insulin and contractions were observed between the two training groups. The second experiment demonstrated that GLUT-4 content after HIT did not differ from that after RHT (66% higher in trained rats than in control). In conclusion, the present investigation demonstrated that 8 days of HIT lasting only 280 s elevated both GLUT-4 content and maximal glucose transport activity in rat skeletal muscle to a level similar to that attained after LIT, which has been considered a tool to increase GLUT-4 content maximally.


1996 ◽  
Vol 81 (4) ◽  
pp. 1501-1509 ◽  
Author(s):  
Jørgen F. P. Wojtaszewski ◽  
Bo F. Hansen ◽  
Birgitte Ursø ◽  
Erik A. Richter

Wojtaszewski, Jørgen F. P., Bo F. Hansen, Birgitte Ursø, and Erik A. Richter. Wortmannin inhibits both insulin- and contraction-stimulated glucose uptake and transport in rat skeletal muscle. J. Appl. Physiol. 81(4): 1501–1509, 1996.—The role of phosphatidylinositol (PI) 3-kinase for insulin- and contraction-stimulated muscle glucose transport was investigated in rat skeletal muscle perfused with a cell-free perfusate. The insulin receptor substrate-1-associated PI 3-kinase activity was increased sixfold upon insulin stimulation but was unaffected by contractions. In addition, the insulin-stimulated PI 3-kinase activity and muscle glucose uptake and transport in individual muscles were dose-dependently inhibited by wortmannin with one-half maximal inhibition values of ∼10 nM and total inhibition at 1 μM. This concentration of wortmannin also decreased the contraction-stimulated glucose transport and uptake by ∼30–70% without confounding effects on contractility or on muscle ATP and phosphocreatine concentrations. At higher concentrations (3 and 10 μM), wortmannin completely blocked the contraction-stimulated glucose uptake but also decreased the contractility. In conclusion, inhibition of PI 3-kinase with wortmannin in skeletal muscle coincides with inhibition of insulin-stimulated glucose uptake and transport. Furthermore, in contrast to recent findings in incubated muscle, wortmannin also inhibited contraction-stimulated glucose uptake and transport. The inhibitory effect of wortmannin on contraction-stimulated glucose uptake may be independent of PI 3-kinase activity or due to inhibition of a subfraction of PI 3-kinase with low sensitivity to wortmannin.


1990 ◽  
Vol 259 (6) ◽  
pp. E778-E786 ◽  
Author(s):  
T. Ploug ◽  
B. M. Stallknecht ◽  
O. Pedersen ◽  
B. B. Kahn ◽  
T. Ohkuwa ◽  
...  

The effect of 10 wk endurance swim training on 3-O-methylglucose (3-MG) uptake (at 40 mM 3-MG) in skeletal muscle was studied in the perfused rat hindquarter. Training resulted in an increase of approximately 33% for maximum insulin-stimulated 3-MG transport in fast-twitch red fibers and an increase of approximately 33% for contraction-stimulated transport in slow-twitch red fibers compared with nonexercised sedentary muscle. A fully additive effect of insulin and contractions was observed both in trained and untrained muscle. Compared with transport in control rats subjected to an almost exhaustive single exercise session the day before experiment both maximum insulin- and contraction-stimulated transport rates were increased in all muscle types in trained rats. Accordingly, the increased glucose transport capacity in trained muscle was not due to a residual effect of the last training session. Half-times for reversal of contraction-induced glucose transport were similar in trained and untrained muscles. The concentrations of mRNA for GLUT-1 (the erythrocyte-brain-Hep G2 glucose transporter) and GLUT-4 (the adipocyte-muscle glucose transporter) were increased approximately twofold by training in fast-twitch red muscle fibers. In parallel to this, Western blot demonstrated a approximately 47% increase in GLUT-1 protein and a approximately 31% increase in GLUT-4 protein. This indicates that the increases in maximum velocity for 3-MG transport in trained muscle is due to an increased number of glucose transporters.


1997 ◽  
Vol 273 (3) ◽  
pp. C1082-C1087 ◽  
Author(s):  
A. D. Lee ◽  
P. A. Hansen ◽  
J. Schluter ◽  
E. A. Gulve ◽  
J. Gao ◽  
...  

beta-Adrenergic stimulation has been reported to inhibit insulin-stimulated glucose transport in adipocytes. This effect has been attributed to a decrease in the intrinsic activity of the GLUT-4 isoform of the glucose transporter that is mediated by phosphorylation of GLUT-4. Early studies showed no inhibition of insulin-stimulated glucose transport by epinephrine in skeletal muscle. The purpose of this study was to determine the effect of epinephrine on GLUT-4 phosphorylation, and reevaluate the effect of beta-adrenergic stimulation on insulin-activated glucose transport, in skeletal muscle. We found that 1 microM epinephrine, which raised adenosine 3',5'-cyclic monophosphate approximately ninefold, resulted in GLUT-4 phosphorylation in rat skeletal muscle but had no inhibitory effect on insulin-stimulated 3-O-methyl-D-glucose (3-MG) transport. In contrast to 3-MG transport, the uptakes of 2-deoxyglucose and glucose were markedly inhibited by epinephrine treatment. This inhibitory effect was presumably mediated by stimulation of glycogenolysis, which resulted in an increase in glucose 6-phosphate concentration to levels known to severely inhibit hexokinase. We conclude that 1) beta-adrenergic stimulation decreases glucose uptake by raising glucose 6-phosphate concentration, thus inhibiting hexokinase, but does not inhibit insulin-stimulated glucose transport and 2) phosphorylation of GLUT-4 has no effect on glucose transport in skeletal muscle.


2000 ◽  
Vol 88 (6) ◽  
pp. 2240-2245 ◽  
Author(s):  
Thomas H. Reynolds ◽  
Joseph T. Brozinick ◽  
Lisa M. Larkin ◽  
Samuel W. Cushman

The purpose of the present study was to examine the effect of detraining on the glucose transport system after short-term swim training (5 days), long-term swim training (5 wk), and treadmill run training (5 wk). Skeletal muscles were isolated from female Wistar rats at 24 or 48 h posttraining. SST produces a 48% increase in GLUT-4 mRNA, a 30% increase in GLUT-4 protein, and a 60% increase in insulin-stimulated glucose transport activity at 24 h posttraining but not at 48 h posttraining. Similar to SST, long-term swim training produces a 60% increase in GLUT-4 mRNA and a 30% increase in GLUT-4 protein content at 24 h posttraining but not at 48 h posttraining. Finally, treadmill run training produces a transient 35% increase in GLUT-4 protein content that is completely reversed at 48 h after the last bout of exercise. These results demonstrate that the increase in GLUT-4 mRNA and GLUT-4 protein occurs during the first week of exercise training and is rapidly lost after training cessation. We believe that the transient enhancement in GLUT-4 protein after exercise training is due to a short GLUT-4 half-life, a process that is primarily regulated by pretranslational mechanisms.


2001 ◽  
Vol 280 (1) ◽  
pp. E130-E142 ◽  
Author(s):  
Ben B. Yaspelkis ◽  
James R. Davis ◽  
Maziyar Saberi ◽  
Toby L. Smith ◽  
Reza Jazayeri ◽  
...  

In addition to suppressing appetite, leptin may also modulate insulin secretion and action. Leptin was administered here to insulin-resistant rats to determine its effects on secretagogue-stimulated insulin release, whole body glucose disposal, and insulin-stimulated skeletal muscle glucose uptake and transport. Male Wistar rats were fed either a normal (Con) or a high-fat (HF) diet for 3 or 6 mo. HF rats were then treated with either vehicle (HF), leptin (HF-Lep, 10 mg · kg−1 · day−1 sc), or food restriction (HF-FR) for 12–15 days. Glucose tolerance and skeletal muscle glucose uptake and transport were significantly impaired in HF compared with Con. Whole body glucose tolerance and rates of insulin-stimulated skeletal muscle glucose uptake and transport in HF-Lep were similar to those of Con and greater than those of HF and HF-FR. The insulin secretory response to either glucose or tolbutamide (a pancreatic β-cell secretagogue) was not significantly diminished in HF-Lep. Total and plasma membrane skeletal muscle GLUT-4 protein concentrations were similar in Con and HF-Lep and greater than those in HF and HF-FR. The findings suggest that chronic leptin administration reversed a high-fat diet-induced insulin-resistant state, without compromising insulin secretion.


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