The second-meal phenomenon is associated with enhanced muscle glycogen storage in humans

2009 ◽  
Vol 117 (3) ◽  
pp. 119-127 ◽  
Author(s):  
Ana Jovanovic ◽  
Emily Leverton ◽  
Bhavana Solanky ◽  
Balasubramanian Ravikumar ◽  
Johanna E. M. Snaar ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Muscle Glycogen ◽  
Standardized Test ◽  
Glycogen Synthesis ◽  
Random Order ◽  
Glycogen Storage ◽  
Resonance Spectroscopy ◽  
Plasma Nefa ◽  
Muscle Glycogen Synthesis ◽  
Metabolic Basis

The rise in blood glucose after lunch is less if breakfast has been eaten. The metabolic basis of this second-meal phenomenon remains uncertain. We hypothesized that storage of ingested glucose as glycogen could be responsible during the post-meal suppression of plasma NEFAs (non-esterified fatty acids; ‘free’ fatty acids). In the present study we determined the metabolic basis of the second-meal phenomenon. Healthy subjects were studied on two separate days, with breakfast and without breakfast in a random order. We studied metabolic changes after a standardized test lunch labelled with 3 g of 13C-labelled (99%) glucose. Changes in post-prandial muscle glycogen storage were measured using 13C magnetic resonance spectroscopy. The rise in plasma glucose after lunch was significantly less if breakfast had been taken (0.9±0.3 compared with 3.2±0.3 mmol/l, with and without breakfast respectively; P<0.001), despite comparable insulin responses. Pre-lunch NEFAs were suppressed after breakfast (0.13±0.03 compared with 0.51±0.04 mmol/l) and levels correlated positively with the maximum glucose rise after lunch (r=0.62, P=0.001). The increase in muscle glycogen signal was greater 5 h after lunch on the breakfast day (103±21 compared with 48±12 units; P<0.007) and correlated negatively with plasma NEFA concentrations before lunch (r=−0.48, P<0.05). The second-meal effect is associated with priming of muscle glycogen synthesis consequent upon sustained suppression of plasma NEFA concentrations.

Direct measurement of change in muscle glycogen concentration after a mixed meal in normal subjects

1993 ◽  
Vol 265 (2) ◽  
pp. E224-E229 ◽  
Author(s):  
R. Taylor ◽  
T. B. Price ◽  
L. D. Katz ◽  
R. G. Shulman ◽  
G. I. Shulman
Keyword(s):  
Muscle Glycogen ◽  
Glycogen Synthesis ◽  
Normal Subjects ◽  
Resonance Spectroscopy ◽  
Mixed Meal ◽  
Glycogen Concentration ◽  
Carbohydrate Storage ◽  
13C Nuclear Magnetic Resonance ◽  
Muscle Glycogen Synthesis ◽  
Muscle Glycogen Concentration

Postprandial storage of carbohydrate as glycogen in muscle was quantitated in normal subjects (n = 8) by natural abundance 13C-nuclear magnetic resonance spectroscopy with proton decoupling in a 4.7-tesla magnet. After an overnight fast three basal measurements of gastrocnemius muscle glycogen were made and a mixed meal was given. Muscle glycogen concentration rose from 83.3 +/- 5.2 to a maximum of 100.2 +/- 6.7 mmol/l muscle at 4.9 h (P < 0.01) and fell thereafter to 90.6 +/- 5.9 mmol/l muscle at 7 h postprandially (P < 0.006). The meal brought about an increase in plasma glucose from 5.4 +/- 0.2 to 7.3 +/- 0.4 mmol/l at 30 min but this was followed by a rapid fall to 6.2 +/- 0.4 mmol/l at 75 min. Plasma insulin rose from 62.4 +/- 11.4 to 900 +/- 216 pmol/l at 30 min and declined steadily thereafter. It was calculated from total muscle mass measurements and estimation of carbohydrate absorption rates that at peak muscle glycogen concentrations between 26 and 35% of the absorbed carbohydrate was stored as muscle glycogen. These data quantitate the role of skeletal muscle glycogen synthesis in postprandial carbohydrate storage and demonstrate that this tissue acts as a dynamic buffer to maintain glucose homeostasis during postprandial substrate storage.

scholarly journals Postexercise muscle glycogen resynthesis in humans

2017 ◽  
Vol 122 (5) ◽  
pp. 1055-1067 ◽  
Author(s):  
Louise M. Burke ◽  
Luc J. C. van Loon ◽  
John A. Hawley
Keyword(s):  
Muscle Glycogen ◽  
Glycogen Synthesis ◽  
Practical Interest ◽  
Time Frame ◽  
Glycogen Storage ◽  
Future Research ◽  
Glycogen Depletion ◽  
Muscle Glycogen Synthesis ◽  
The 1960S ◽  
Dietary Strategies

Since the pioneering studies conducted in the 1960s in which glycogen status was investigated using the muscle biopsy technique, sports scientists have developed a sophisticated appreciation of the role of glycogen in cellular adaptation and exercise performance, as well as sites of storage of this important metabolic fuel. While sports nutrition guidelines have evolved during the past decade to incorporate sport-specific and periodized manipulation of carbohydrate (CHO) availability, athletes attempt to maximize muscle glycogen synthesis between important workouts or competitive events so that fuel stores closely match the demands of the prescribed exercise. Therefore, it is important to understand the factors that enhance or impair this biphasic process. In the early postexercise period (0–4 h), glycogen depletion provides a strong drive for its own resynthesis, with the provision of CHO (~1 g/kg body mass) optimizing this process. During the later phase of recovery (4–24 h), CHO intake should meet the anticipated fuel needs of the training/competition, with the type, form, and pattern of intake being less important than total intake. Dietary strategies that can enhance glycogen synthesis from suboptimal amounts of CHO or energy intake are of practical interest to many athletes; in this scenario, the coingestion of protein with CHO can assist glycogen storage. Future research should identify other factors that enhance the rate of synthesis of glycogen storage in a limited time frame, improve glycogen storage from a limited CHO intake, or increase muscle glycogen supercompensation.

Insulin promotes glycogen synthesis in the absence of GSK3 phosphorylation in skeletal muscle

2008 ◽  
Vol 294 (1) ◽  
pp. E28-E35 ◽  
Author(s):  
Michale Bouskila ◽  
Michael F. Hirshman ◽  
Jørgen Jensen ◽  
Laurie J. Goodyear ◽  
Kei Sakamoto
Keyword(s):  
Skeletal Muscle ◽  
Glucose Uptake ◽  
Muscle Glycogen ◽  
Glycogen Content ◽  
Glycogen Synthase ◽  
Glycogen Synthesis ◽  
Wild Type ◽  
Muscle Glycogen Synthesis ◽  
Mutant Forms

Insulin promotes dephosphorylation and activation of glycogen synthase (GS) by inactivating glycogen synthase kinase (GSK) 3 through phosphorylation. Insulin also promotes glucose uptake and glucose 6-phosphate (G-6- P) production, which allosterically activates GS. The relative importance of these two regulatory mechanisms in the activation of GS in vivo is unknown. The aim of this study was to investigate if dephosphorylation of GS mediated via GSK3 is required for normal glycogen synthesis in skeletal muscle with insulin. We employed GSK3 knockin mice in which wild-type GSK3α and -β genes are replaced with mutant forms (GSK3α/βS21A/S21A/S9A/S9A), which are nonresponsive to insulin. Although insulin failed to promote dephosphorylation and activation of GS in GSK3α/βS21A/S21A/S9A/S9Amice, glycogen content in different muscles from these mice was similar compared with wild-type mice. Basal and epinephrine-stimulated activity of muscle glycogen phosphorylase was comparable between wild-type and GSK3 knockin mice. Incubation of isolated soleus muscle in Krebs buffer containing 5.5 mM glucose in the presence or absence of insulin revealed that the levels of G-6- P, the rate of [14C]glucose incorporation into glycogen, and an increase in total glycogen content were similar between wild-type and GSK3 knockin mice. Injection of glucose containing 2-deoxy-[3H]glucose and [14C]glucose also resulted in similar rates of muscle glucose uptake and glycogen synthesis in vivo between wild-type and GSK3 knockin mice. These results suggest that insulin-mediated inhibition of GSK3 is not a rate-limiting step in muscle glycogen synthesis in mice. This suggests that allosteric regulation of GS by G-6- P may play a key role in insulin-stimulated muscle glycogen synthesis in vivo.

Can photobiomodulation therapy (PBMT) control blood glucose levels and alter muscle glycogen synthesis?

2020 ◽  
Vol 207 ◽  
pp. 111877 ◽  
Author(s):  
Kenia Mendes Rodrigues Castro ◽  
Rodrigo Leal de Paiva Carvalho ◽  
Geraldo Marco Rosa Junior ◽  
Beatriz Antoniassi Tavares ◽  
Luis Henrique Simionato ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Muscle Glycogen ◽  
Glycogen Synthesis ◽  
Photobiomodulation Therapy ◽  
Control Blood Glucose ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Muscle Glycogen Synthesis
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