Effect of epinephrine on glucose disposal during exercise in humans: role of muscle glycogen

2002 ◽  
Vol 283 (3) ◽  
pp. E578-E583 ◽  
Author(s):  
Matthew J. Watt ◽  
Mark Hargreaves

This study examined the effect of epinephrine on glucose disposal during moderate exercise when glycogenolytic flux was limited by low preexercise skeletal muscle glycogen availability. Six male subjects cycled for 40 min at 59 ± 1% peak pulmonary O2 uptake on two occasions, either without (CON) or with (EPI) epinephrine infusion starting after 20 min of exercise. On the day before each experimental trial, subjects completed fatiguing exercise and then maintained a low carbohydrate diet to lower muscle glycogen. Muscle samples were obtained after 20 and 40 min of exercise, and glucose kinetics were measured using [6,6-2H]glucose. Exercise increased plasma epinephrine above resting concentrations in both trials, and plasma epinephrine was higher ( P < 0.05) during the final 20 min in EPI compared with CON. Muscle glycogen levels were low after 20 min of exercise (CON, 117 ± 25; EPI, 122 ± 20 mmol/kg dry matter), and net muscle glycogen breakdown and muscle glucose 6-phosphate levels during the subsequent 20 min of exercise were unaffected by epinephrine infusion. Plasma glucose increased with epinephrine infusion (i.e., 20–40 min), and this was due to a decrease in glucose disposal (Rd) (40 min: CON, 33.8 ± 3; EPI, 20.9 ± 4.9 μmol · kg−1 · min−1, P < 0.05), because the exercise-induced rise in glucose rate of appearance was similar in the trials. These results show that glucose Rd during exercise is reduced by elevated plasma epinephrine, even when muscle glycogen availability and utilization are low. This suggests that the effect of epinephrine does not appear to be mediated by increased glucose 6-phosphate, secondary to enhanced muscle glycogenolysis, but may be linked to a direct effect of epinephrine on sarcolemmal glucose transport.

1982 ◽  
Vol 48 (02) ◽  
pp. 201-203 ◽  
Author(s):  
N A Marsh ◽  
P J Gaffney

SummaryThe effect of strenuous exercise on the fibrinolytic and coagulation mechanisms was examined in six healthy male subjects. Five min bicycle exercise at a work-rate of 800 to 1200 kpm. min−1 produced an abrupt increase in plasma plasminogen activator levels which disappeared after 90 min. However, there was no change in early or late fibrin degradation products nor was there a change in fibrinopeptide A levels or βthromboglobulin levels after exercise although activated partial thromboplastin times were significantly shortened. It is concluded that strenuous exercise does not produce any real increase in fibrinogen-fibrin conversion nor any real increase in the breakdown of these proteins. The role of exercise-induced release of plasminogen activator remains unclear, but probably helps to maintain plasma levels in a discontinuous manner concurrently with the continuous low-level secretion from the vascular wall. The shortening of partial thromboplastin time may be due to the raised levels of plasminogen activator changing the activation state of other coagulation factors.


2006 ◽  
Vol 101 (3) ◽  
pp. 695-706 ◽  
Author(s):  
T. A. Duhamel ◽  
H. J. Green ◽  
J. G. Perco ◽  
J. Ouyang

The effects of exercise and diet on sarcoplasmic reticulum Ca2+-cycling properties in female vastus lateralis muscle were investigated in two groups of women following four different conditions. The conditions were 4 days of a low-carbohydrate (Lo CHO) and glycogen-depleting exercise plus a Lo CHO diet (Ex + Lo CHO) ( experiment 2) and 4 days of normal CHO (Norm CHO) and glycogen-depleting exercise plus Norm CHO (Ex + Norm CHO) ( experiment 1). Peak aerobic power (V̇o2peak) was 38.1 ± 1.4 (SE); n = 9 and 35.6 ± 1.4 ml·kg−1·min−1; n = 9, respectively. Sarcoplasmic reticulum properties measured in vitro in homogenates (μmol·g protein−1·min−1) indicated exercise-induced reductions ( P < 0.05) in maximal Ca2+-ATPase activity (0 > 30, 60 min > fatigue), Ca2+ uptake (0 > 30 > 60 min, fatigue), and Ca2+ release, both phase 1 (0, 30 > 60 min, fatigue) and phase 2 (0 > 30, 60 min, fatigue; 30 min > fatigue) in Norm CHO. Exercise was without effect in altering the Hill slope ( nH), defined as the slope of relationship between Ca2+-ATPase activity and Ca2+ concentration. No differences were observed between Norm CHO and Ex+Norm CHO. Compared with Norm CHO, Lo CHO resulted in a lower ( P < 0.05) Ca2+ uptake, phase 1 Ca2+ release (30 min), and nH. Ex + Lo CHO resulted in a greater ( P < 0.05) Ca2+ uptake and nH compared with Lo CHO. The results demonstrate that Lo CHO alone can disrupt SR Ca2+ cycling and that, with the exception of Ca2+ release, a glycogen-depleting session of exercise before Lo CHO can reverse the effects.


2020 ◽  
Vol 105 (11) ◽  
Author(s):  
Eric Lontchi-Yimagou ◽  
Sandra Aleksic ◽  
Raphael Hulkower ◽  
Rebekah Gospin ◽  
Akankasha Goyal ◽  
...  

Abstract Background Recurrent hypoglycemia blunts counter-regulatory responses to subsequent hypoglycemic episodes, a syndrome known as hypoglycemia-associated autonomic failure (HAAF). Since adrenergic receptor blockade has been reported to prevent HAAF, we investigated whether the hypoglycemia-associated rise in plasma epinephrine contributes to pathophysiology and reported interindividual differences in susceptibility to HAAF. Methods To assess the role of hypoglycemia-associated epinephrine responses in the susceptibility to HAAF, 24 adult nondiabetic subjects underwent two 2-hour hyperinsulinemic hypoglycemic clamp studies (nadir 54 mg/dL; 0-2 hours and 4-6 hours) on Day 1, followed by a third identical clamp on Day 2. We challenged an additional 7 subjects with two 2-hour infusions of epinephrine (0.03 μg/kg/min; 0-2 hours and 4-6 hours) vs saline on Day 1 followed by a 200-minute stepped hypoglycemic clamp (90, 80, 70, and 60 mg/dL) on Day 2. Results Thirteen out of 24 subjects developed HAAF, defined by ≥20% reduction in average epinephrine levels during the final 30 minutes of the third compared with the first hypoglycemic episode (P &lt; 0.001). Average epinephrine levels during the final 30 minutes of the first hypoglycemic episode were 2.3 times higher in subjects who developed HAAF compared with those who did not (P = 0.006). Compared to saline, epinephrine infusion on Day 1 reduced the epinephrine responses by 27% at the 70 and 60 mg/dL glucose steps combined (P = 0.04), with a parallel reduction in hypoglycemic symptoms (P = 0.03) on Day 2. Conclusions Increases in plasma epinephrine reproduce key features of HAAF in nondiabetic subjects. Marked interindividual variability in epinephrine responses to hypoglycemia may explain an individual’s susceptibility to developing HAAF.


2016 ◽  
Vol 310 (7) ◽  
pp. R631-R639 ◽  
Author(s):  
Anthony Sclafani ◽  
Hermann Koepsell ◽  
Karen Ackroff

Recent findings suggest that the intestinal sodium-glucose transporter 1 (SGLT1) glucose transporter and sensor mediates, in part, the appetite-stimulation actions of intragastric (IG) glucose and nonmetabolizable α-methyl-d-glucopyranoside (MDG) infusions in mice. Here, we investigated the role of SGLT1 in sugar conditioning using SGLT1 knockout (KO) and C57BL/6J wild-type (WT) mice. An initial experiment revealed that both KO and WT mice maintained on a very low-carbohydrate diet display normal preferences for saccharin, which was used in the flavored conditioned stimulus (CS) solutions. In experiment 2, mice were trained to drink one flavored solution (CS+) paired with an IG MDG infusion and a different flavored solution (CS−) paired with IG water infusion. In contrast to WT mice, KO mice decreased rather than increased the intake of the CS+ during training and failed to prefer the CS+ over the CS− in a choice test. In experiment 3, the KO mice also decreased their intake of a CS+ paired with IG glucose and avoided the CS+ in a choice test, unlike WT mice, which preferred the CS+ to CS−. In experiment 4, KO mice, like WT mice preferred a glucose + saccharin solution to a saccharin solution. These findings support the involvement of SGLT1 in post-oral glucose and MDG conditioning. The results also indicate that sugar malabsorption in KO mice has inhibitory effects on sugar intake but does not block their natural preference for sweet taste.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A439-A439
Author(s):  
Emi Ishida ◽  
Xiao Lei ◽  
Kazuhiko Horiguchi ◽  
Shunichi Matsumoto ◽  
Satoshi Yoshino ◽  
...  

Abstract In type 2 diabetes, pancreatic beta cells are gradually ‘exhausted’ and fall into beta cell dysfunction, which proceeds more severe insulin dependence. Among the proposed mechanisms of beta cell dysfunction such as endoplasmic reticulum stress and oxidative stress, the beta cell heterogeneity has attracted the researcher’s interest recently. In 2012, Talchai et al. revealed that the beta cells were dedifferentiated in diabetic mice model, and nowadays it is considered as one form of the beta cell heterogeneity and is observed broadly among diabetic animal models and human patients. Previously we showed that food restriction had the best effect to restore beta cell gene expression in obese diabetic model mice, among the known diabetic treatments which we tested. In the current study, we aimed to unveil the molecular basis in the improvement of beta cell dedifferentiation during the calorie restriction. First, we utilized the high-fat/low carbohydrate diet (HF) or low-fat/high carbohydrate (HC) diet, to determine whether fat restriction or sugar restriction reduces the beta cell dedifferentiation in obese mice. When calorie intake was restricted evenly, both HF diet and HC diet decreased the body weight and hyperglycemia in db/db mice equally. Albeit the same metabolic profile, db/db group fed with HC diet had more enlarged islets and more dedifferentiated beta cell features than db/dbs fed with HF diet, which indicated the compensatory beta cell response in HC diet group. Moreover, HC diet group showed more severe fatty liver than HF diet group, along with the elevated synthesis and accumulation of triglycerides and cholesterol in liver. It is speculated that the insulin resistance in liver might impact on the beta cell dedifferentiation. Next, we analyzed the effect of glucagon-like peptide 1 (GLP-1) on beta cell dedifferentiation, since GLP-1 is secreted more from intestine by protein and fat intake, rather than by sugar intake. Also, increasing number of reports have suggested the improving effect of GLP-1 on beta cell dysfunction and fatty liver. Indeed, GLP-1 administration altered the reduced beta cell/alpha cell ratio in db/db mice, which indicated the restoration of beta cell heterogeneity. We are now investigating if GLP-1 administration reimburse the beta cell dedifferentiation in db/db mice fed with HC diet, to illuminate the role of incretins in beta cell dedifferentiation induced by unbalanced nutrition during diet. Also, we will present the RNA sequencing data of the liver in db/db mice fed with HF and HC diet, to elucidate the key molecules and genes which connect the beta cell function and metabolic state in liver.


PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257275
Author(s):  
Leila Setayesh ◽  
Reyhane Ebrahimi ◽  
Sara Pooyan ◽  
Habib Yarizadeh ◽  
Elaheh Rashidbeygi ◽  
...  

Background Previous studies showed the possible association between obesity, dietary pattern, and depressive symptoms. Due to the lack of enough data to confirm the association of obesity and depression in the Middle East, here, we aimed to explore the possible mediatory role of adipokines Galectin-3, transforming growth factor-beta (TGF-β), and endothelial plasminogen activator inhibitor (PAI-1) in the association between low carbohydrate diet (LCD) and depressive symptoms. Methods A total of 256 women aged 17–56 years old were grouped based on their LCD score. Depression anxiety stress scales-21 (DASS-21) self-administered questionnaire was used to evaluate the three negative emotional states of stress, depressive symptoms, and anxiety. Body composition and dietary intake were assessed. Enzyme-linked immunosorbent assay (ELISA) was used to measure the serum levels of Galectin-3, TGF-β, and PAI-1. Results No significant difference was observed regarding Galectin-3, TGF-β, and PAI-1 levels between the groups with dissimilar adherence to LCD or the groups with different levels of depressive symptoms (P>0.05). However, there was a negative association between LCD score as a covariant and depressive symptoms as an independent variable (P = 0.02) and remarkably, a regression model linear analysis using Galectin-3, TGF-β, and PAI-1 as confounding variables indicated the mediatory role of these adipokines in this association (P>0.05). In other words, adipokines eliminated the significance of the relationship between adherence to LCD and depressive symptoms. Conclusion It seems that higher adherence to LCD is probably associated with a lower prevalence of depressive symptoms in obese adults through the mediatory role of adipokines.


Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6878
Author(s):  
Min Jae Kim ◽  
Sung Hyun Hong ◽  
Wonhee Cho ◽  
Dong-Hyuk Park ◽  
Eun-Byeol Lee ◽  
...  

The purpose of our study was to validate a newly developed breath acetone (BrAce) analyzer, and to explore if BrAce could predict aerobic exercise-related substrate use. Six healthy men ran on a treadmill at 70% of maximal oxygen consumption (VO2max) for 1 h after two days of a low-carbohydrate diet. BrAce and blood ketone (acetoacetate (ACAC), beta-hydroxybutyrate (BOHB)) levels were measured at baseline and at different time points of post-exercise. BrAce values were validated against blood ketones and respiratory exchange ratio (RER). Our results showed that BrAce was moderately correlated with BOHB (r = 0.68, p < 0.01), ACAC (r = 0.37, p < 0.01) and blood ketone (r = 0.60, p < 0.01), suggesting that BrAce reflect blood ketone levels, which increase when fat is oxidized. Furthermore, BrAce also negatively correlated with RER (r = 0.67, p < 0.01). In our multiple regression analyses, we found that when BMI and VO2max were added to the prediction model in addition to BrAce, R2 values increased up to 0.972 at rest and 0.917 at 1 h after exercise. In conclusion, BrAce level measurements of our BrAce analyzer reflect blood ketone levels and the device could potentially predict fat oxidation.


2005 ◽  
Vol 98 (1) ◽  
pp. 100-107 ◽  
Author(s):  
Tanya L. Pehleman ◽  
Sandra J. Peters ◽  
George J. F. Heigenhauser ◽  
Lawrence L. Spriet

Whole body glucose disposal and skeletal muscle hexokinase, glycogen synthase (GS), pyruvate dehydrogenase (PDH), and PDH kinase (PDK) activities were measured in aerobically trained men after a standardized control diet (Con; 51% carbohydrate, 29% fat, and 20% protein of total energy intake) and a 56-h eucaloric, high-fat, low-carbohydrate diet (HF/LC; 5% carbohydrate, 73% fat, and 22% protein). An oral glucose tolerance test (OGTT; 1 g/kg) was administered after the Con and HF/LC diets with vastus lateralis muscle biopsies sampled pre-OGTT and 75 min after ingestion of the oral glucose load. The 90-min area under the blood glucose and plasma insulin concentration vs. time curves increased by 2-fold and 1.25-fold, respectively, after the HF/LC diet. The pre-OGTT fraction of GS in its active form and the maximal activity of hexokinase were not affected by the HF/LC diet. However, the HF/LC diet increased PDK activity (0.19 ± 0.05 vs. 0.08 ± 0.02 min−1) and decreased PDH activation (0.38 ± 0.08 vs. 0.79 ± 0.10 mmol acetyl-CoA·kg wet muscle−1·min−1) before the OGTT vs. Con. During the OGTT, GS and PDH activation increased by the same magnitude in both diets, such that PDH activation remained lower during the HF/LC OGTT (0.60 ± 0.11 vs. 1.04 ± 0.09 mmol acetyl-CoA·kg−1·min−1). These data demonstrate that the decreased glucose disposal during the OGTT after the 56-h HF/LC diet was in part related to decreased oxidative carbohydrate disposal in skeletal muscle and not to decreased glycogen storage. The rapid increase in PDK activity during the HF/LC diet appeared to account for the reduced potential for oxidative carbohydrate disposal.


1998 ◽  
Vol 84 (2) ◽  
pp. 465-470 ◽  
Author(s):  
M. A. Febbraio ◽  
D. L. Lambert ◽  
R. L. Starkie ◽  
J. Proietto ◽  
M. Hargreaves

Febbraio, M. A., D. L. Lambert, R. L. Starkie, J. Proietto, and M. Hargreaves. Effect of epinephrine on muscle glycogenolysis during exercise in trained men. J. Appl. Physiol. 84(2): 465–470, 1998.—To test the hypothesis that an elevation in circulating epinephrine increases intramuscular glycogen utilization, six endurance-trained men performed two 40-min cycling trials at 71 ± 2% of peak oxygen uptake in 20–22°C conditions. On the first occasion, subjects were infused with saline throughout exercise (Con). One week later, after determination of plasma epinephrine levels in Con, subjects performed the second trial (Epi) with an epinephrine infusion, which resulted in a twofold higher ( P < 0.01) plasma epinephrine concentration in Epi compared with Con. Although oxygen uptake was not different when the two trials were compared, respiratory exchange ratio was higher throughout exercise in Epi compared with Con (0.93 ± 0.01 vs. 0.89 ± 0.01; P < 0.05). Muscle glycogen concentration was not different when the trials were compared preexercise, but the postexercise value was lower ( P < 0.01) in Epi compared with Con. Thus net muscle glycogen utilization was greater during exercise with epinephrine infusion (224 ± 37 vs. 303 ± 30 mmol/kg for Con and Epi, respectively; P < 0.01). In addition, both muscle and plasma lactate and plasma glucose concentrations were higher ( P < 0.05) in Epi compared with Con. These data indicate that intramuscular glycogen utilization, glycolysis, and carbohydrate oxidation are augmented by elevated epinephrine during submaximal exercise in trained men.


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