Glycogen availability can influence glucose transporter 4 (GLUT4) expression in skeletal muscle through unknown mechanisms. The multisubstrate enzyme AMP-activated protein kinase (AMPK) has also been shown to play an important role in the regulation of GLUT4 expression in skeletal muscle. During contraction, AMPK [alpha]2 translocates to the nucleus and the activity of this AMPK isoform is enhanced when skeletal muscle glycogen is low. In this study, we investigated if decreased pre-exercise muscle glycogen levels and increased AMPK [alpha]2 activity reduced the association of AMPK with glycogen and increased AMPK [alpha]2 translocation to the nucleus and GLUT4 mRNA expression following exercise. Seven males performed 60 min of exercise at ~70% [VO.sub.2] peak on 2 occasions: either with normal (control) or low (LG) carbohydrate pre-exercise muscle glycogen content. Muscle samples were obtained by needle biopsy before and after exercise. Low muscle glycogen was associated with elevated AMPK ...
Purpose: To evaluate the efficacy of using combined glucose and fructose (GF) ingestion as a means to stimulate short-term (4 h) postexercise muscle glycogen synthesis compared to glucose only (G). Methods: On two separate occasions, six endurance-trained men performed an exhaustive glycogen-depleting exercise bout followed by a 4-h recovery period. Muscle biopsy samples were obtained from the vastus lateralis muscle at 0, 1, and 4 h after exercise. Subjects ingested carbohydrate solutions containing G (90 gIhj1) or GF (G = 60 gIhj1; F = 30 gIhj1) commencing immediately after exercise and every 30 min thereafter. Results: Immediate postexercise muscle glycogen concentrations were similar in both trials (G = 128 T 25 mmolIkgj1 dry muscle (dm) vs GF = 112 T 16 mmolIkgj1 dm; P 9 0.05). Total glycogen storage during the 4-h recovery period was 176 T 33 and 155 T 31 mmolIkgj1 dm for G and GF, respectively (G vs GF, P 9 0.05). Hence, mean muscle glycogen synthesis rates during the 4-h recovery period ...
TY - JOUR. T1 - Influence of muscle glycogen availability on ERK1/2 and Akt signaling after resistance exercise in human skeletal muscle. AU - Creer, Andrew. AU - Gallagher, Philip. AU - Slivka, Dustin. AU - Jemiolo, Bozena. AU - Fink, William. AU - Trappe, Scott. PY - 2005/9. Y1 - 2005/9. N2 - Two pathways that have been implicated for cellular growth and development in response to muscle contraction are the extracellular signal-regulated kinase (ERK1/2) and Akt signaling pathways. Although these pathways are readily stimulated after exercise, little is known about how nutritional status may affect stimulation of these pathways in response to resistance exercise in human skeletal muscle. To investigate this, experienced cyclists performed 30 repetitions of knee extension exercise at 70% of one repetition maximum after a low (2%) or high (77%) carbohydrate (LCHO or HCHO) diet, which resulted in low or high (∼174 or ∼591 mmol/kg dry wt) preexercise muscle glycogen content. Muscle biopsies ...
TY - JOUR. T1 - Epinephrine regulation of skeletal muscle glycogen metabolism. Studies utilizing the perfused rat hindlimb preparation. AU - Dietz, M. R.. AU - Chiasson, J. L.. AU - Soderling, T. R.. AU - Exton, J. H.. PY - 1980/12/1. Y1 - 1980/12/1. N2 - Studies of rat skeletal muscle glycogen metabolism carried out in a perfused hindlimb system indicated that epinephrine activates phosphorylase via the cascade of phosphorylation reactions classically linked to the β-adrenergic receptor/adenylate cyclase system. The β blocker propranolol completely blocked the effects of epinephrine on cAMP, cAMP-dependent protein kinase, phosphorylase, and glucose-6-P, whereas the α blocker phentolamine was totally ineffective. Omission of glucose from the perfusion medium did not modify the effects of epinephrine. Glycogen synthase activity in control perfused and nonperfused muscle was largely glucose-6-P-dependent (-glucose-6-P/+glucose-6-P activity ratios of 0.1 and 0.2, respectively). Epinephrine ...
Glycogen plays a major role in supporting the energy demands of skeletal muscles during high intensity exercise. Despite its importance, the amount of glycogen stored in skeletal muscles is so small that a large fraction of it can be depleted in response to a single bout of high intensity exercise. For this reason, it is generally recommended to ingest food after exercise to replenish rapidly muscle glycogen stores, otherwise ones ability to engage in high intensity activity might be compromised. But what if food is not available? It is now well established that, even in the absence of food intake, skeletal muscles have the capacity to replenish some of their glycogen at the expense of endogenous carbon sources such as lactate. This is facilitated, in part, by the transient dephosphorylation-mediated activation of glycogen synthase and inhibition of glycogen phosphorylase. There is also evidence that muscle glycogen synthesis occurs even under conditions conducive to an increased oxidation of ...
In Saccharomyces cerevisiae, nutrient levels control multiple cellular processes. Cells lacking the SNF1 gene cannot express glucose-repressible genes and do not accumulate the storage polysaccharide glycogen. The impaired glycogen synthesis is due to maintenance of glycogen synthase in a hyperphosphorylated, inactive state. In a screen for second site suppressors of the glycogen storage defect of snf1 cells, we identified a mutant gene that restored glycogen accumulation and which was allelic with PHO85, which encodes a member of the cyclin-dependent kinase family. In cells with disrupted PHO85 genes, we observed hyperaccumulation of glycogen, activation of glycogen synthase, and impaired glycogen synthase kinase activity. In snf1 cells, glycogen synthase kinase activity was elevated. Partial purification of glycogen synthase kinase activity from yeast extracts resulted in the separation of two fractions by phenyl-Sepharose chromatography, both of which phosphorylated and inactivated glycogen ...
1. A description is given of the hour-to-hour variation in the liver glycogen content in adult male mice, and it is shown that the concentration is highest while the animals are asleep and lowest while they are awake.. 2. A similar cycle is also described in the glycogen content of the skin. Histologically it is shown that a high proportion of the skin glycogen lies in the cytoplasm of the epidermal cells, and that during sleep both the epidermal glycogen content and the epidermal mitotis rate increase considerably. The skin glycogen content and the epidermal mitotic activity also show a marked increase after a subcutaneous injection of 20 mg. starch, while they are both abnormally depressed after two injections of 1/50 unit insulin.. 3. These results, together with others previously reported, are in agreement with the theory that at the onset of sleep glucose is deposited from the blood into the tissues where it appears in the form of glycogen. Since it is known that glucose, or glycogen, is a ...
Glycogen synthase (UDP-glucose-glycogen glucosyltransferase) is a key enzyme in glycogenesis, the conversion of glucose into glycogen. It is a glycosyltransferase (EC 2.4.1.11) that catalyses the reaction of UDP-glucose and (1,4-α-D-glucosyl)n to yield UDP and (1,4-α-D-glucosyl)n+1. In other words, this enzyme combines excess glucose residues one by one into a polymeric chain for storage as glycogen. Glycogen synthase concentration is highest in the bloodstream 30 to 60 minutes following intense exercise. Much research has been done on glycogen degradation through studying the structure and function of glycogen phosphorylase, the key regulatory enzyme of glycogen degradation. On the other hand, much less is known about the structure of glycogen synthase, the key regulatory enzyme of glycogen synthesis. The crystal structure of glycogen synthase from Agrobacterium tumefaciens, however, has been determined at 2.3 A resolution. In its asymmetric form, glycogen synthase is found as a dimer, whose ...
Muscle glycogen resynthesis rate in humans after supplementation of drinks containing carbohydrates with low and high molecular masses ...
Eccentric contractions induce muscle damage, which impairs recovery of glycogen and adenosine tri-phosphate (ATP) content over several days. Leucine-enriched essential amino acids (LEAAs) enhance the recovery in muscles that are damaged after eccentric contractions. However, the role of LEAAs in this process remains unclear. We evaluated the content in glycogen and high energy phosphates molecules (phosphocreatine (PCr), adenosine di-phosphate (ADP) and ATP) in rats that were following electrically stimulated eccentric contractions. Muscle glycogen content decreased immediately after the contraction and remained low for the first three days after the stimulation, but increased seven days after the eccentric contraction. LEAAs administration did not change muscle glycogen content during the first three days after the contraction. Interestingly, however, it induced a further increase in muscle glycogen seven days after the stimulation. Contrarily, ATP content decreased immediately after the eccentric
TY - JOUR. T1 - Analysis of respiratory mutants reveals new aspects of the control of glycogen accumulation by the cyclin-dependent protein kinase Pho85p. AU - Wilson, Wayne A.. AU - Wang, Zhong. AU - Roach, P. J.. PY - 2002/3/27. Y1 - 2002/3/27. N2 - The PHO85 gene of Saccharomyces cerevisiae encodes a cyclin-dependent protein kinase that can interact with 10 different cyclins (Pcls). In conjunction with Pcl8p and Pcl10p, Pho85p phosphorylates and regulates glycogen synthase. Respiratory-deficient strains, such as coq3 mutants, have reduced glycogen stores and contain hyperphosphorylated and inactive glycogen synthase. We show here that pho85 coq3 mutants have dephosphorylated and active glycogen synthase yet do not maintain glycogen reserves. In contrast, deletion of PCL8 and PCL10 in the coq3 mutant background partially restores glycogen accumulation. This suggested the existence of inputs from Pho85p into glycogen storage, independent of Pcl8p and Pcl10p, and acting antagonistically.. AB - ...
TY - JOUR. T1 - 13C NMR studies of glycogen turnover in the perfused rat liver. AU - Shulman, G. I.. AU - Rothman, D. L.. AU - Chung, Youngran. AU - Rossetti, L.. AU - Petit, W. A.. AU - Barrett, E. J.. AU - Shulman, R. G.. PY - 1988. Y1 - 1988. N2 - To assess whether hepatic glycogen is actively turning over under conditions which promote net glycogen synthesis we perfused livers from 24-h fasted rats with 20 mM D-[1-13C]glucose, 10 mM L-[3-13C]alanine, 10 mM L-[3-13C]lactate, and 1 μM insulin for 90 min followed by a 75-min chase period with perfusate of the same composition containing either 13C-enriched or unlabeled substrates. The peak height of the C-1 resonance of the glucosyl subunits in glycogen was monitored, in real time, using 13C NMR techniques. During the initial 90 min the peak height of the C-1 resonance of glycogen increased at almost a constant rate reflecting a near linear increase in net glycogen synthesis, which persisted for a further 75 min if 13C-enriched substrates ...
Muscle glycogen availability can limit endurance exercise performance. We previously demonstrated 5 days of creatine (Cr) and carbohydrate (CHO) ingestion augmented post-exercise muscle glycogen storage compared to CHO feeding alone in healthy volunteers. Here, we aimed to characterise the time-cour …
The cDNA for mouse brain glycogen synthase has been isolated by screening a mouse cerebral cortical astrocyte lambda ZAP II cDNA library. The mouse brain glycogen synthase cDNA is 3.5 kilobases in length and encodes a protein of 737 amino acids. The coding sequence of mouse brain glycogen synthase cDNA shares approximately 87% nucleotide identity and approximately 96% amino acid identity with the muscle isozyme, while the degree of identity is lower with the liver isozyme. The regional distribution of glycogen synthase mRNA determined by in situ hybridization in the mouse brain reveals a wide distribution throughout the central nervous system with highest densities observed in the cerebellum, hippocampus and olfactory bulb. At the cellular level the expression of brain glycogen synthase mRNA is localized both in astrocytes and neurons with, however, the higher levels observed in astrocytes. Vasoactive intestinal peptide and noradrenaline, two neurotransmitters previously shown to induce a glycogen
Background: Diabetic cardiomyopathy is a distinct cardiac pathology and the underlying mechanisms are unknown. Elevated glycogen content has been observed in the diabetic human myocardium, first recorded 80 years ago, suggesting that despite impaired glucose uptake cardiomyocytes accumulate glycogen. Anecdotal evidence of glycogen accumulation in the diabetic myocardium has since been recorded in the literature but a systematic investigation of this paradoxical phenomenon has not been conducted. Glycogen storage diseases demonstrate that increased cardiac glycogen is associated with severe functional deficits, and therefore the observed glycogen excess in diabetic hearts may be an important and novel agent of pathology in diabetic cardiomyopathy. Aim: This body of work aimed to systematically investigate the role myocardial glycogen accumulation in diabetic cardiomyopathy, with a focus on glycophagy, a glycogen-specific autophagy process. Key metabolic signaling pathways (insulin, AMPK, ...
It is generally acknowledged that fasted animals recovering from physical activity of near-maximal intensity can replenish their muscle glycogen stores even in the absence of food intake. In some mammal species, such as in rats and humans, the extent of this replenishment is only partial (Hermansen and Vaage, 1977; Astrand et al., 1986; Choi et al., 1994; Nikolovski et al., 1996; Peters et al., 1996; Bangsbo et al., 1997; Ferreira et al., 2001; Fournier et al., 2002), thus suggesting that a few consecutive bouts of high-intensity exercise might eventually lead to the progressive depletion of their muscle glycogen stores. In order to test this prediction, groups of rats were subjected to a series of three bouts of high-intensity swims to exhaustion, each separated from the subsequent one by a recovery period previously shown to be long enough for muscle glycogen and lactate to return to stable levels (Ferreira et al., 2001). This study shows for the first time that repeated bouts of ...
Since its identification more than 150 years ago, there has been an extensive characterisation of glycogen metabolism and its regulatory pathways in the two main glycogen storage organs of the body, i.e. liver and muscle. In recent years, glycogen metabolism has also been demonstrated to be upregulated in many tumour types, suggesting it is an important aspect of cancer cell pathophysiology. Here, we provide an overview of glycogen metabolism and its regulation, with a focus on its role in metabolic reprogramming of cancer cells. The various methods to detect glycogen in tumours in vivo are also reviewed. Finally, we discuss the targeting of glycogen metabolism as a strategy for cancer treatment.
In obesity, insulin-stimulated glucose uptake in skeletal muscle is decreased. We investigated whether the stimulatory effect of acute exercise on glucose uptake and subsequent glycogen synthesis was normal. The study was performed on 18 healthy volu
Hepatic glycogen synthesis is impaired in insulin-dependent diabetic rats and in adrenalectomized starved rats, and although this is known to be due to defective activation of glycogen synthase by glycogen synthase phosphatase, the underlying molecular mechanism has not been delineated. Glycogen synthase phosphatase comprises the catalytic subunit of protein phosphatase 1 (PP1) complexed with the hepatic glycogen-binding subunit, termed GL. In liver extracts of insulin-dependent diabetic and adrenalectomized starved rats, the level of GL was shown by immunoblotting to be substantially reduced compared with that in control extracts, whereas the level of PP1 catalytic subunit was not affected by these treatments. Insulin administration to diabetic rats restored the level of GL and prolonged administration raised it above the control levels, whereas re-feeding partially restored the GL level in adrenalectomized starved rats. The regulation of GL protein levels by insulin and starvation/feeding was ...
Title: Glycogen and its Metabolism. VOLUME: 2 ISSUE: 2. Author(s):Peter J. Roach. Affiliation:MS405A, Medical ScienceBuilding, 635 Barnhill Drive, Indianapolis, IN 46202, USA. Keywords:glycogen, phosphorylayion, catecholamines, glycogenolysis, glycogenin, glycogen synthesis, glycogen synthase, glycogen phosphorylase, acid glucosidase. Abstract: Glycogen is a branched polymer of glucose which serves as a reservoir of glucose units. The two largest deposits in mammals are in the liver and skeletal muscle but many cells are capable synthesizing glycogen. Its accumulation and utilization are under elaborate controls involving primarily covalent phosphorylation and allosteric ligand binding. Both muscle and liver glycogen reserves are important for whole body glucose metabolism and their replenishment is linked hormonally to nutritional status. Control differs between muscle and liver in part due to the existence of different tissue-specific isoforms at key steps. Control of synthesis is shared ...
Muscle glycogen provides a readily available source of glucose-1-phosphate for glycolysis within the muscle itself. Liver glycogen functions as a reserve to maintain the blood glucose concentration in the fasting state. The liver concentration of glycogen is about 450 mmol /L glucose equivalents after a meal, falling to about 200 mmol /L after an overnight fast; after 12 to 18 hours of fasting, liver glycogen is almost totally depleted. Although muscle glycogen does not directly yield free glucose (because muscle lacks glucose-6-phosphatase), pyruvate formed by glycolysis in muscle can undergo transamination to alanine, which is exported from muscle and used for gluconeogenesis in the liver (see Figure 19-4). Glycogen storage diseases are a group of inherited disorders characterized by deficient mobilization of glycogen or deposition of abnormal forms of glycogen, leading to liver damage and muscle weakness; some glycogen storage diseases result in early death. ...
Glycogen content and contraction strongly regulate glycogen synthase (GS) activity, and the aim of the present study was to explore their effects and interaction on GS phosphorylation and kinetic properties. Glycogen content in rat epitrochlearis muscles was manipulated in vivo. After manipulation, incubated muscles with normal glycogen [NG; 210.9 ± 7.1 mmol/kg dry weight (dw)], low glycogen (LG; 108.1 ± 4.5 mmol/ kg dw), and high glycogen (HG; 482.7 ± 42.1 mmol/kg dw) were contracted or rested before the studies of GS kinetic properties and GS phosphorylation (using phospho-specific antibodies). LG decreased and HG increased GS Km for UDP-glucose (LG: 0.27 ± 0.02 , NG: 0.71 ± 0.06 , HG: 1.11 ± 0.12 mM; P , 0.001). In addition, GS fractional activity inversely correlated with glycogen content (R = -0.70; P , 0.001; n = 44). Contraction decreased Km for UDP-glucose (LG: 0.14 ± 0.01 = NG: 0.16 ± 0.01 , HG: 0.33 ± 0.03 mM; P , 0.001) and increased GS fractional activity, and these effects ...
TY - JOUR. T1 - Factors influencing pituitary glycogen metabolism and gonadotropic hormone release. I. Luteinizing hormone releasing hormone. AU - Makino, T.. AU - Demers, L. M.. AU - Greep, R. O.. PY - 1974/1/1. Y1 - 1974/1/1. N2 - The mechanism of release of luteinizing hormone (LH) and follicle stimulating hormone (FSH) from the rat anterior pituitary by LH releasing hormone (LH RH) was further evaluated by studies on pituitary glycogen metabolism and its relation to the hormone release mechanism in vitro. Pituitary glycogen content and the activity levels of its 2 major regulatory enzymes, glycogen synthetase and glycogen phosphorylase, were analyzed after exposure to different doses of synthetic LH RH in vitro. Less than 5 ng of LH RH induced within minutes a maximum glycogenolytic response with an increase in the proportion of pituitary phosphorylase in the more active a form and a decrease in pituitary glycogen. Exogenous N6,O2 dibutyryl cyclic AMP (10 millimol) with theophylline (1 ...
Transcription of metabolic genes is transiently induced during recovery from exercise in skeletal muscle of humans. To determine whether pre-exercise muscle glycogen content influences the magnitude and/or duration of this adaptive response, six male subjects performed one-legged cycling exercise to lower muscle glycogen content in one leg and then, the following day, completed 2.5 h low intensity two-legged cycling exercise. Nuclei and mRNA were isolated from biopsies obtained from the vastus lateralis muscle of the control and reduced glycogen (pre-exercise glycogen = 609 ± 47 and 337 ± 33 mmol kg-1 dry weight, respectively) legs before and after 0, 2 and 5 h of recovery. Exercise induced a significant (P 6-fold) than in the control (< 3-fold) trial. Induction of PDK4 and UCP3 mRNA in response to exercise was also signficantly higher in the low glycogen (11.4- and 3.5-fold, respectively) than in the control (5.0- and 1.7-fold, respectively) trial. These data indicate that low muscle ...
Recovery is governed by the length of time taken to fully restore muscle glycogen. Muscle glycogen is depleted after 2-3 hours of continuous exercise at 60-80% VO2max. Glycogen depletion can also occur after 15-20 min of very intense exercise at 90-130% VO2max. Low muscle glycogen levels increase the risk of injury. Restoration of muscle glycogen can take 20 hours with correct diet and supplementation. Less than an optimal diet will increase recovery time. CHO replenishment during exercise seems to be optimal at 7-8% concentration in water. However, after exercise it can be of a much higher concnetration. Implication. For intermittent high intensity sports (e.g., soccer, hockey) the ingestion of CHO throughout the game, and during any rest period will result in muscle glycogen being restored and increased sprinting ability towards the end of the game. This will not happen when only water is consumed. Return to Table of Contents for this issue. ...
Protein targeting to glycogen (PTG) is a scaffolding protein that targets protein phosphatase 1α (PP1α) to glycogen, and links it to enzymes involved in glycogen synthesis and degradation. We generated mice that possess a heterozygous deletion of the PTG gene. These mice have reduced glycogen stores in adipose tissue, liver, heart, and skeletal muscle, corresponding with decreased glycogen synthase activity and glycogen synthesis rate. Although young PTG heterozygous mice initially demonstrate normal glucose tolerance, progressive glucose intolerance, hyperinsulinemia, and insulin resistance develop with aging. Insulin resistance in older PTG heterozygous mice correlates with a significant increase in muscle triglyceride content, with a corresponding attenuation of insulin receptor signaling. These data suggest that PTG plays a critical role in glycogen synthesis and is necessary to maintain the appropriate metabolic balance for the partitioning of fuel substrates between glycogen and ...
Key points Muscle glycogen (the storage form of glucose) is consumed during muscle work and the depletion of glycogen is thought to be a main contributor to muscle fatigue. In this study, we used a novel approach to first measure fatigue-induced reductions in force and tetanic Ca2+ in isolated single mouse muscle fibres following repeated contractions and subsequently quantify the subcellular distribution of glycogen in the same fibre. Using this approach, we investigated whether the decreased tetanic Ca2+ induced by repeated contractions was associated with glycogen depletion in certain subcellular regions. The results show a positive correlation between depletion of glycogen located within the myofibrils and low tetanic Ca2+ after repetitive stimulation. We conclude that subcellular glycogen depletion has a central role in the decrease in tetanic Ca2+ that occurs during repetitive contractions. In skeletal muscle fibres, glycogen has been shown to be stored at different subcellular locations: ...
Looking for glycogen synthetase? Find out information about glycogen synthetase. An enzyme that catalyzes the synthesis of the amylose chain of glycogen Explanation of glycogen synthetase
The time of ingestion of a carbohydrate supplement on muscle glycogen storage postexercise was examined. Twelve male cyclists exercised continuously for 70 min on a cycle ergometer at 68% VO2max, interrupted by six 2-min intervals at 88% VO2max, on two separate occasions. A 25% carbohydrate solution …
Your diet can have a major impact on your bodys ability to produce glycogen. This is especially the case if youre on a low-carb diet where youre reducing the number of carbohydrates youre consuming with each meal.. It should be noted that low-carb diets come with their own side effects, primarily because your bodys glycogen stores may not have the fuel needed to replenish properly, resulting in symptoms of mental dullness and fatigue. Over time, your body should adjust to these changes, and your glycogen stores should replenish, bringing your energy levels back up to normal.. In the same manner, you may experience a decrease in glycogen stores if you lose any amount of weight. As many people who have been on a diet may have experienced, weight loss may occur initially, but may eventually plateau and even begin increasing after a certain point.. This process occurs partially because glycogen is primarily made up of water, making up three to four times the weight of the molecule itself. ...
It is also significant that conditions 1 & 2 above caused greater glycogen to be utilized during the test run (21k) than the 3rd condition. BUT, the authors said there was no difference in the run times between groups, and the post-exercise glycogen levels between groups were similar. What does this mean? Carbo loading may increase glycogen stores, which translates to greater glycogen utilization during the run. However, this doesnt benefit performance. What is most interesting to me is that the low-CHO diet for the first 3 days had virtually no benefit over a moderate-CHO diet (in terms of glycogen storage). This could be the study that Rich was referring to when he talked about the myth of carbo-loading. It has been generally accepted that the depletion phase of 1970s-sytle carboloading is of no greater benefit than eating a moderately high CHO diet and pushing additional carbs in the 72 hours preceding depleting exercise. SO, then, Chucks assertion that restricting carbs 7-4 days ...
Assuming that your workout or race starts in the morning, the purpose of your pre-race meal is to top off liver glycogen stores, which your body has expended during your night of sleep. Muscle glycogen, the first fuel recruited when exercise commences, remains intact overnight. If you had a proper recovery meal after your last workout, youll have a full load of muscle glycogen on board, which constitutes about 80% of your total glycogen stores. If you didnt re-supply with complex carbs and protein after your last workout, theres nothing you can do about it now; in fact, youll only hurt yourself by trying. To repeat: during sleep, your liver-stored glycogen maintains proper blood glucose level; you expend nary a calorie of your muscle glycogen. You might wake up feeling hungry, and Ill discuss that issue later, but youll have a full supply of muscle-stored glycogen, your bodys first used and main energy source. Your stomach might be saying, Im hungry, but your muscles are saying, Hey, ...
Glucose and muscle glycogen (the storage form of glucose) The main source of fuel during intense weight training. Low muscle glycogen levels can limit your wor
We examined whether carbohydrate-protein ingestion influences muscle glycogen metabolism during short-term recovery from exhaustive treadmill running and subsequent exercise. Six endurance-trained individuals underwent two trials in a randomized double-blind design, each involving an initial run-to-exhaustion at 70% VO2max (Run-1) followed by 4-h recovery (REC) and subsequent run-to-exhaustion at 70% VO2max (Run-2). Carbohydrate-protein (CHO-P; 0.8 g carbohydrate·kg body mass [BM-1]·h-1 plus 0.4 g protein·kg BM-1·h-1) or isocaloric carbohydrate (CHO; 1.2 g carbohydrate·kg BM-1·h-1) beverages were ingested at 30-min intervals during recovery. Muscle biopsies were taken upon cessation of Run-1, postrecovery and fatigue in Run-2. Time-to-exhaustion in Run-1 was similar with CHO and CHO-P (81 ± 17 and 84 ± 19 min, respectively). Muscle glycogen concentrations were similar between treatments after Run-1 (99 ± 3 mmol·kg dry mass [dm-1]). During REC, muscle glycogen concentrations increased ...
I recently experienced an extreme bout of glycogen depletion. Glycogen keeps your muscles moving and brain functioning - when you run out of it you bonk or hit the wall... actually in the 1960s, it was determined that the major source of carbohydrate during exercise was the muscle glycogen stores. It was demonstrated that the capacity…
Re muscles. When exercising - and this is important - muscles cells will also take up glucose, even in the (relative - cos you always have at least some in your circulation )absence of insulin. Exercise ( via AMPK ? ) stimulates a secondary pool of GLUT4 which then go get glucose. Perhaps most importantly, this can last for betwen 24 to 36hours, and is in part why exercise is recommended for diabetics etc and also why they tell you not to let much more than a day to pass between exercising. Re HIIT. As well as promoting the above, it also very rapidly empties muscle glycogen stores. In intensive exercise, the cells cannot get sufficient fuel quickly enough from the circulation, so the muscle glycogen stores get used up rapidly and HIIT is one of the best ways of doing this. So when youve finished exercising, the muscle cells will immediately replenish this. All of which, in addition to the above, helps keep your blood glucose levels down ...
Glycogen granule definition at Dictionary.com, a free online dictionary with pronunciation, synonyms and translation. Look it up now!
Citrulline pulls the glucose switch on your metabolic switchboard. Galactose is the better glucose - at least when it comes to pre-/intra-workout nutrition. There is no need to hurry glycogen repletion, if your next 5k is still 24h away. 4 weeks are not enough for your antioxidant defenses to recover from 3 weeks of overreaching...
Glycogenin-1 is an enzyme that is involved in the biosynthesis of glycogen. This enzyme is important for the function of self-glucosylated to form an oligosaccharide primer that serves as substrate for glycogen synthase. This is done through an inter-subunit mechanism. It also plays a role in glycogen metabolism regulation and in the maximal glycogen levels attaintment in skeletal muscle. Recombinant human glycogenin-1 was expressed in E. coli and purified by using conventional chromatography techniques. Glycogen is a multi branched polysaccharide. It is the way all the animal cells have to store glucose. In the human body, the two main tissues of glycogen accumulation are liver and skeletal muscle. The concentration of this polysaccharide is superior at the liver, but, due to the major mass of skeletal that muscle humans have, this tissue contains three quarters of the corporal glycogen. On the one hand, the function of the liver glycogen is to maintain glucose homeostasis as a way to ...
A note on carbohydrate (carbo) loading: Carbo-loading is a method some athletes use to maximize glycogen stores. The original method began 1 week prior to the event. For the first 3 days, athletes ate a very low carbohydrate diet (about 10% of total calories) and exercised intensely to deplete glycogen stores. The following 3 days the athlete ate a very high carbohydrate diet (about 90% of total calories) and reduced exercise intensity to maximize glycogen stores. Over the years this technique has been modified and the depletion phase has basically been eliminated. Now athletes usually just increase carbohydrate intake for the 3 days prior to the event (about 70% of calories) and decrease exercise intensity. Consult a physician before attempting a carbo-loading diet.. Protein. Protein is needed for muscle and tissue growth and repair. However, too much protein can cause dehydration and muscle heaviness. When muscle glycogen stores are high, protein contributes less than 5% of the energy needed ...
Constitutively active protein kinase that acts as a negative regulator in the hormonal control of glucose homeostasis, Wnt signaling and regulation of transcription factors and microtubules, by phosphorylating and inactivating glycogen synthase (GYS1 or GYS2), CTNNB1/beta-catenin, APC and AXIN1. Requires primed phosphorylation of the majority of its substrates. Contributes to insulin regulation of glycogen synthesis by phosphorylating and inhibiting GYS1 activity and hence glycogen synthesis. Regulates glycogen metabolism in liver, but not in muscle. May also mediate the development of insulin resistance by regulating activation of transcription factors. In Wnt signaling, regulates the level and transcriptional activity of nuclear CTNNB1/beta-catenin. Facilitates amyloid precursor protein (APP) processing and the generation of APP-derived amyloid plaques found in Alzheimer disease. May be involved in the regulation of replication in pancreatic beta-cells. Is necessary for the establishment of neuronal
The exact composition of Glycogen Solution is confidential. The Glycogen concentration is 20mg/mL. Glycogen Solution is a component of Gentra Puregene Kits for DNA purification. During isopropanol precipitation, Glycogen Solution acts as a nucleic acid carrier and helps to efficiently precipitate small amounts of DNA. In addition, it facilitates visualization of the DNA pellet. Glycogen Solution can be purchased separately ...
Glycogen Biosynthesis; Glycogen Breakdown Glycogen - Wikipedia Glycogen is the analogue of starch, a glucose polymer that functions as energy storage in plants. It has a structure similar to amylopectin (a component of starch),.... ...
Using mice that overexpress PTG specifically in the liver, we examined the impact of liver glycogen on food intake. The overexpression of this protein caused an increase in hepatic glycogen stores in mice. When fed an HFD, these animals decreased their food intake and had a lower body weight and decreased fat mass. Changes in key regulators of food intake in the hypothalamus support the decrease in appetite observed in these animals. Expression of POMC, an anorexigenic signal, increased, whereas that of orexigenic NPY decreased. These data support the idea that liver glycogen stores regulate food intake, thus reinforcing the glycogenostatic theory (12). However, in the present study, this effect was limited to hyperphagic conditions, such as HFD. Friedman (34) proposed that changes in glycogen stores do not necessarily signal changes in food intake; rather, the partitioning of carbohydrates in and out of glycogen affects eating behavior by altering fuel fluxes, and, by analogy to fat fuels, ...
What does it do for your muscles and burning fat?. Understanding the relationship between carbohydrates and glycogen can help you respond better to the demands of your body. Sometimes the more active we become and cleaner with our nutrition your glycogen levels can find themselves in a deficit. When your glycogen is low and needs to be replenished we can appear leaner and tighter. However, mentally we may feel foggy and tired. Have you ever notice after eating unclean food, had an all out binge and woke up the next day feeling just as tight, you swear maybe even tighter? You think your eyes are playing tricks on you. This may actually be the case! That is likely because your glycogen levels were low and eating that rich food restored them, letting the body let go of retained water and provided the illusion of swelled muscles to gain that look of tightness. You may even have heard of some fitness athletes before a shoot will plan a couple glasses of wine and a sweet treat the night before. This ...
Many organisms store energy in the form of polysaccharides, commonly homopolymers of glucose. Glycogen, the polysaccharide used by animals to store energy, is composed of alpha-1,4-glycosidic bonds with branched alpha-1,6 bonds present at about every tenth monomer. Starch, used by plant cells, is similar in structure but exists in two forms: amylose is the helical form of starch comprised only of alpha-1,4 linkages, and amylopectin has a structure like glycogen except that the branched alpha-1,6 linkages are present on only about one in 30 monomers. These polysaccharides often contain tens of thousands of monomers, and each type is synthesized in the cell and broken down when energy is needed. Glycogen metabolism is an intricate process involving many enzymes and cofactors resulting in the regular release and storage of glucose. This metabolic process is in turn broken down to glycogen degradation and synthesis. Glycogen synthesis is carried out by the enzyme glycogen synthase in which the ...
antibody-antibodies.com is the marketplace for research antibodies. Find the right antibody for your research needs. Cardiomyopathy and exercise intolerance in muscle glycogen storage disease 0.
The aim of these experiments was to investigate the interrelationships of fat and carbohydrate (CHO) metabolism in mammalian muscle. In particular, it was hoped to clarify the mechanisms regulating the integration of the supply and utilisation of metabolic substrates in skeletal muscle. This was achieved by studying the response to a perturbation of normal metabolic processes. Administration of a low CHO diet following exereise-induced glycogen depletion resulted in a situation where the muscle and liver glycogen stores were lower than normal, and the availability of plasma FFA was greater than normal. Administration of a high CHO diet immediately following the low CHO diet resulted in the achievement of greater than normal glycogen stores and a restricted availability of FFA. Subjects were studied at rest and during exercise of different intensities at each stage of this dietary regime Measurements were made of blood metabolites and cardiovascular and respiratory parameters. Following the low ...
Where does the myth of the superiority of low intensity cardio come from? Does high intensity exercise take a toll on your antioxidant defense system? Why is burning glycogen actually nothing bad? And what
TY - JOUR. T1 - Amino acid sequence at the site on rabbit skeletal muscle glycogen synthase phosphorylated by the endogenous glycogen synthase kinase-2 activity. AU - Rylatt, Dennis B.. AU - Cohen, Philip. PY - 1979/2/1. Y1 - 1979/2/1. UR - http://www.scopus.com/inward/record.url?scp=0018438921&partnerID=8YFLogxK. U2 - 10.1016/0014-5793(79)80154-4. DO - 10.1016/0014-5793(79)80154-4. M3 - Article. C2 - 107044. AN - SCOPUS:0018438921. VL - 98. SP - 71. EP - 75. JO - FEBS Letters. JF - FEBS Letters. SN - 0014-5793. IS - 1. ER - ...
Hormonal control of hepatic glycogen and blood glucose levels is one of the major homeostatic mechanisms in mammals: glycogen is synthesized when portal glucose concentration is sufficiently elevated and degraded when glucose levels are low. We have studied initial events of hepatic glycogen synthesis by injecting the synthetic glucocorticoid dexamethasone (DEX) into adrenalectomized rats fasted overnight. Hepatic glycogen levels are very low in adrenalectomized rats, and DEX causes rapid deposition of the complex carbohydrate. Investigation of the process of glycogen deposition was performed by light and electron microscopic (EM) radioautography using [3H]galactose as a glycogen precursor. Rats injected with DEX for 2-3 h and [3H]galactose one hour before being killed displayed an increasing number of intensely labeled hepatocytes. EM radioautography revealed silver grains over small (+/- 1 micron) ovoid or round areas of the cytosome that were rich in smooth endoplasmic reticulum (SER) and ...
TY - JOUR. T1 - Glycogen metabolism in a Saccharomyces cerevisiae phosphoglucose isomerase (pgi1) disruption mutant. AU - Corominas, Josep. AU - Clotet, Josep. AU - Fernández-Bañares, Isabel. AU - Boles, Eckhard. AU - Zimmmermann, Friedrich K.. AU - Guinovart, Joan J.. AU - Ariño, Joaquín. PY - 1992/9/28. Y1 - 1992/9/28. N2 - Disruption of the gene pgi1 of Saccharomyces cerevisiae, which codes for phosphoglucose isomerase, results in a dramatic increase in the amount of intracellular glycogen in early exponential cultures. The level or glucose 6-phosphate was much higher in mutant than in wild-type cells. Phosphorylase a activity and the state of activation of glycogen synthase were also investigated. Phosphorylase a activity was rather low along the culture in wild-type cells, whereas it was consistently higher in mutants. Glycogen synthase was mostly in the active form in early-medium exponential cultures in wild-type cells whereas the activation state of this enzyme in mutant cells, ...
We examined the insulin dose-response characteristics of human muscle glycogen synthase and phosphorylase activation. We also determined whether increasing the rate of glucose disposal by hyperglycemia at a fixed insulin concentration activates glycogen synthase. Physiological increments in plasma insulin but not glucose increased the fractional activity of glycogen synthase. The ED50: s for insulin stimulation of whole body and forearm glucose disposal were similar and unaffected by glycemia. Glycogen synthase activation was exponentially related to the insulin-mediated component of whole body and forearm glucose disposal at each glucose concentration. Neither insulin nor glucose changed glycogen phosphorylase activity. These results suggest that insulin but not the rate of glucose disposal per se regulates glycogen synthesis by a mechanism that involves dephosphorylation of glycogen synthase but not phosphorylase. This implies that the low glycogen synthase activities found in ...
Author(s): Roa, Jinae N; Tresguerres, Martin | Abstract: Na+/K+-ATPase (NKA)- and vacuolar H+-ATPase (VHA)-rich cells in shark gills secrete excess acid and base, respectively, to seawater to maintain blood acid-base homeostasis. Both cell types are rich in mitochondria, indicating high ATP demand; however, their metabolic fuel is unknown. Here, we report that NKA- and VHA-rich cells have large glycogen stores. Glycogen abundance in NKA-rich cells was lower in starved sharks compared with 24 h post-fed sharks, reflecting higher energy demand for acid secretion during normal activity and glycogen replenishment during the post-feeding period. Conversely, glycogen abundance in VHA-rich cells was high in starved sharks and it became depleted post-feeding. Furthermore, inactive cells with cytoplasmic VHA had large glycogen stores and active cells with basolateral VHA had depleted glycogen stores. These results indicate that glycogen is a main energy source in both NKA- and VHA-rich cells, and point to
Supercompensated brain glycogen levels may contribute to the development of hypoglycemia-associated autonomic failure (HAAF) following recurrent hypoglycemia (RH) by providing energy for the brain during subsequent periods of hypoglycemia. To assess the role of glycogen supercompensation in the generation of HAAF, we estimated the level of brain glycogen following RH and acute hypoglycemia (AH). After undergoing 3 hyperinsulinemic, euglycemic and 3 hyperinsulinemic, hypoglycemic clamps (RH) on separate occasions at least 1 month apart, five healthy volunteers received [1-C]glucose intravenously over 80+ h while maintaining euglycemia. C-glycogen levels in the occipital lobe were measured by C magnetic resonance spectroscopy at ∼8, 20, 32, 44, 56, 68 and 80 h at 4 T and glycogen levels estimated by fitting the data with a biophysical model that takes into account the tiered glycogen structure. Similarly, prior C-glycogen data obtained following a single hypoglycemic episode (AH) were fitted ...
Sarcoplasmic vesicles and ß-glycogen particles 30-40 mµ in diameter were isolated from perfused rabbit skeletal muscle by the differential precipitation-centrifugation method. This microsomal fraction was subjected to zonal centrifugation on buffered sucrose gradients, in a B XIV Anderson type rotor, for 15 hr at 45,000 rpm in order to separate the two cytoplasmic organelles. Zonal profiles of absorbance at 280 mµ, proteins, glycogen, and enzymatic activities (phosphorylase b kinase, phosphorylase b, and glycogen synthetase) were performed. Whereas the entire synthetase activity was found combined with the glycogen particles, 39% of phosphorylase and 53% of phosphorylase b kinase activities, present in the microsomal fraction, were recovered in the purified vesicular fraction (d = 1.175). This latter fraction consists of vesicles, derived from the sarcoplasmic reticulum, and of small particles 10-20 mµ in diameter attached to the outer surface of the membranes. These particles disappear ...
TY - JOUR. T1 - Complete reversal of glycogen hepatopathy with pancreas transplantation. T2 - Two cases. AU - Fridell, Jonathan A.. AU - Saxena, Romil. AU - Chalasani, Naga. AU - Goggins, William C.. AU - Powelson, John A.. AU - Cummings, Oscar. PY - 2007/1. Y1 - 2007/1. N2 - Glycogen hepatopathy is the pathological overloading of hepatocytes with glycogen that is associated with poorly controlled diabetes mellitus. Clinically, it presents with abdominal discomfort, tender hepatomegaly and elevated transaminases. In this report, we describe our experience with two cases of type I diabetes mellitus and glycogen hepatopathy. The patients underwent isolated pancreas transplantation, following which, we have been able to demonstrate complete histological resolution of glycogen hepatopathy associated with control of glucose metabolism.. AB - Glycogen hepatopathy is the pathological overloading of hepatocytes with glycogen that is associated with poorly controlled diabetes mellitus. Clinically, it ...
TY - JOUR. T1 - Studies on the mechanism by which exogenous glucose is converted into liver glycogen in the rat. A direct or an indirect pathway?. AU - Newgard, C. B.. AU - Hirsch, L. J.. AU - Foster, D. W.. AU - McGarry, J. D.. PY - 1983/1/1. Y1 - 1983/1/1. N2 - To quantify the extent to which exogenous glucose is used directly or indirectly for hepatic glycogen synthesis, fasted rats were given [U-14C,3-3H]glucose intragastrically, intravenously, or as a component of a solid diet eaten ad libitum. In all cases liver glycogen was deposited at high linear rates over a 3-h period. Portal vein glucose levels seldom exceeded 8 mM. At a time when the specific activities of 3H and 14C in circulating glucose were identical with those in the administered material their values in newly synthesized glycogen were reduced by 72-88% and 50-65%, respectively. An intragastric load of unlabeled glucose sufficient to suppress completely hepatic glucose output greatly stimulated the incorporation of ...
1. During conversion of [6-3H,U-14C]glucose to glycogen in liver, loss of 6-3H can occur either by cycling via pyruvate (between glycolysis and gluconeogenesis) or by other mechanisms. We used mercaptopicolinate, an inhibitor of phosphoenolpyruvate carboxykinase, to determine the extent to which pyruvate cycling contributes to loss of 6-3H during glucose conversion to glycogen in hepatocytes. 2. Mercaptopicolinate increased the 3H/14C ratio in glycogen during incubation of rat, guinea pig, pig and human hepatocytes with [6-3H,U-14C]glucose. The increase in the 3H/14C ratio in glycogen caused by mercaptopicolinate was greater in periportal than in perivenous rat hepatocytes, indicating that cycling of glucose via pyruvate is more prominent in cells with a higher gluconeogenic relative to glycolytic capacity. 3. The effect of mercaptopicolinate on the 3H/14C ratio in glycogen was observed both in the absence and in the presence of insulin, indicating that stimulation of glycogen synthesis by ...
These are individual glycogen concentrations pre, immediately post, and two hours post 180 min of running at 64% VO2 Max. I would have paid a lot of money for them to keep these guys in the lab, feed them their normal diet, and keep taking daily biopsies to see when each group got back to baseline glycogen concentrations and how this was related to performances on subsequent wingate tests.. Unfortunately, for all of us barbell junkies these guys ran for three hours at a luke warm pace and only got knifed in the leg three times.. Yet, this is the first study to show that fat-adapted athletes had such high resting glycogen concentrations that were not significantly different than high carb athletes and that glycogen replenishment was also not significantly different between groups.. Remember, the results were all over the board in both groups, the study had a small n, and there was no real dietary control. Athletes were also traveling to the lab from all over country the days before testing. ...
Looking for online definition of glycogen infiltration in the Medical Dictionary? glycogen infiltration explanation free. What is glycogen infiltration? Meaning of glycogen infiltration medical term. What does glycogen infiltration mean?
The effect of estradiol and/or clomiphene on blood glucose, uterine and liver glycogen was studied in the rat during delayed implantation. Estrogen induced a sharp increase in uterine glycogen at 6 hours while clomiphene caused a significant increase at 24 hours. Pretreatment with clomiphene inhibited estrogen induced glycogenesis. Estrogen administration resulted in a three fold increase in liver glycogen at 6 hours while clomiphene induced a two fold increase at 24 hours. Pretreatment with clomiphene completely blocked subsequent estrogen action on the liver. The mechanism of estradiol-induced uterine and hepatic glycogenesis as well as the mode of estrogen-clomiphene interaction are discussed. ...
The exact function(s) of the GBD remains unclear, although there are several experimental findings linking AMPK with glycogen; however, these observations are currently difficult to synthesize into a single, all-encompassing hypothesis. The GBD does cause a partial localization of AMPK to glycogen particles, where one of its known downstream targets - glycogen synthase - resides (Hudson et al., 2003). There is also indirect evidence that glycogen regulates AMPK activity: in both rat (Wojtaszewski et al., 2002) and human (Wojtaszewski et al., 2003) skeletal muscle, a high content of glycogen represses activation of AMPK. This makes physiological sense because if muscle glycogen content is high it tends to be used preferentially as fuel and, although AMPK activation stimulates the usage by muscle of alternative fuels such as blood glucose and fatty acids, it is not required for glycogen breakdown or glycolysis. As yet, repression of AMPK activation by glycogen has not been reproduced in a ...
Loss-of-function gac1 mutants of Saccharomyces cerevisiae fail to accumulate normal levels of glycogen because of low glycogen synthase activity. Increased dosage of GAC1 results in increased activity of glycogen synthase and a corresponding hyperaccumulation of glycogen. The glycogen accumulation phenotype of gac1 is similar to that of glc7-1, a type 1 protein phosphatase mutant. We have partially characterized the GAC1 gene product (Gac1p) and show that levels of Gac1p increase during growth with the same kinetics as glycogen accumulation. Gac1p is phosphorylated in vivo and is hyperphosphorylated in a glc7-1 mutant. Gac1p and the type 1 protein phosphatase directly interact in vitro, as assayed by coimmunoprecipitation, and in vivo, as determined by the dihybrid assay described elsewhere (S. Fields and O.-k. Song, Nature [London] 340:245-246, 1989). The interaction between Gac1p and the glc7-1-encoded form of the type 1 protein phosphatase is defective, as assayed by either ...
Lowry Drug Anti Fatigue Caps 90 Capsules [H160252] - Reduce ammonia & reduce fatigue Scavenge excess ammonia to reduce fatigue. Prolong endurance, even in ultra workouts or races. Increase glycogen availability for energy production. Help prevent cramps. Gluten-Free and Vegan Friendly. Extra Benefits:Although Anti-Fatigue Caps is designed primarily for ammonia reduction in long distance events, the nutrients in the formula are excellent for helping counteract everyday fatigue, even chronic fatigue symptoms. Thoroughly tested over several years in the most extreme athletic endurance events, Anti-Fatigue Caps helps remove fatigue-causing, performance-robbing ammonia. During extended endurance exercise the body accumulates excess ammonia from protein metabolism, which interferes with glycogen production, disrupting energy output. Anti-Fatigue Caps is a one-of-a-kind supplement combining two well-known ammonia-scavenging nutrients. Clean up the waste products of combustion, or youll pay the price. To stay
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View Notes - 9-glycogen from STEP 1 at Montgomery College. Biochemistry of Metabolism Glycogen Metabolism Copyright 1999-2007 by Joyce J. Diwan. All rights reserved. CH2OH H OH H CH2OH H OH H OH O H
Gerty Theresa Cori (1896-1957) was awarded a quarter of the 1947 Nobel Prize in Physiology or Medicine for her discovery of how glycogen is broken down and resynthesized in the body to be either used or stored as a source of energy. Her initial research was physiological in nature, and focused on the role of epinephrine in glycogen metabolism. This led to research of a more biochemical nature, including investigations on glycogen breakdown in minced frog muscle. In 1936, she isolated glucose-1-phosphate - also called the Cori ester -- and established that it was a breakdown product of glycogen. Cori also characterized glycogen phosphorylase, the enzyme responsible for breakdown of glycogen to glucose 1-phosphate. In the 1940s, Cori began to purify and crystallize some of the enzymes that she and her husband, Carl, had earlier described, such as glycogen phosphorylase. Cori also elucidated the molecular defects underlying a number of genetically determined glycogen storage diseases.. ...
Taken together, these results further confirmed that (-)-HCA could reduce body weight gain through promoting energy expenditure via its effect on increasing thyroid hormones levels. (-)-Hydroxycitric acid inhibits ATP-citrate lyase and increases the cellular pool of citrate, which in turn inhibits glycolysis and thus redirects the carbon sources for glycogen production within the liver or muscle (Cheng et al., 2012; Shara et al., 2003). No changes were observed on the glucose content, while 1000 mg/kg (-)HCA treatment significantly increased the hepatic glycogen and muscle glycogen contents in rats. Our results is similar to previous study results that show glycogen levels in skeletal muscle are increased after (-)-HCA supplementation in animal models (Ishihara et al., 2000) or in human (Cheng et al., 2012). Our results showed that 2000 mg/kg and 3000 mg/kg (-)-HCA treatment significantly increased insulin content in rats. Insulin can promote the storage of glucose and inhibit lipolysis and ...
Laura:. Check out this research article on marathon race pace. Essentially, we believe that marathoners race best (with exceptions, of course) when their pace is about 15 seconds faster than the first mile of their MAF test. The problem is that if you run any faster than that-that 8:15 pace you want to run in Chicago-your glycogen stores will become depleted too fast and your body wont be able to keep up that speed. Your best bet is to stay close enough to your 1st mile MAF (within 15 seconds) that your glycogen stores dont become depleted. The reason the marathon race pace is always faster than MAF is because you want to be using your muscle glycogen stores enough for them to become completely depleted by the end of the race but not before.. In other words, if your 1st mile MAF pace is say, a 9 min mile pace, it would be very very difficult (not to mention extremely stressful and unhealthy) to be able to keep a 8:15 marathon pace. But most likely, if you do try, youll find that youll hit ...
To evaluate possible mechanisms by which insulin inhibits hepatic apolipoprotein B (apoB) secretion, we incubated primary cultures of rat hepatocytes with sodium ort ho vanadate, a phosphotyrosine phosphatase inhibitor and insulin-mimetic agent. Vanadate (10 μM) and insulin (10 nM) inhibited the medium accumulation of apoB (secretion) by 21 and 37%, respectively, without increasing intracellular apoB. The effects of insulin and vanadate together were not additive. Both insulin and vanadate enhanced intracellular glycogen accumulation by 82 and 37%, respectively. Unlike insulin, vanadate, at a concentration that inhibited apoB secretion (10 μM), had no effect on intracellular lipogenesis, inhibited the secretion of newly synthesized hepatic proteins, and had a delayed onset and termination of action on inhibition of apoB secretion. At higher concentrations (40 and 80 μM), vanadate stimulated intracellular lipogenesis. In conclusion, our data indicate that vanadate mimics insulin action in ...
TY - JOUR. T1 - A conserved domain for glycogen binding in protein phosphatase-1 targeting subunits. AU - Wu, Jun. AU - Liu, Jun. AU - Thompson, Irene. AU - Oliver, Carey J.. AU - Shenolikar, Shirish. AU - Brautigan, David L.. N1 - Funding Information: The authors thank E.Y.C. Lee and John C. Lawrence, Jr. for purified proteins, Charles Richardson and David Metcalf for assistance in obtaining CD spectra, and Christine Palazzolo for assistance in preparation of the manuscript. This research was supported by Grants MCB9507357 from the National Science Foundation (to D.L.B.) and American Diabetes Association (to S.S.). Facilities provided in part by a grant from the Lucille P. Markey Charitable Trust.. PY - 1998/11/13. Y1 - 1998/11/13. N2 - The skeletal muscle glycogen-binding subunit (G(M)) of protein phosphatase-1 (PP1) is the founding member of a family of proteins that tether the PP1 catalytic subunit (PP1C) to glycogen and promote the dephosphorylation of glycogen synthase. A hydrophobic ...
In older endurance athletes, glycogen (carbohydrate) storage per unit of muscle is lower than in similarly trained younger runners while glycogen usage per unit of energy expenditure is higher during endurance exercise. However, following regular endurance training, older individuals are able to increase muscle glycogen storage and restore glycogen stores post-exercise at rates similar to younger athletes.. The recommended carbohydrate intake for athletes (see Table below) is similar to that of the general population and therefore is similar for masters athletes since carbohydrate absorption and utilisation remains intact with aging. Thus, the older athlete should consume at least 55% of daily energy intake as carbohydrate obtained from a variety of food sources and the bulk of the carbohydrate-containing foods consumed should be those rich in complex carbohydrates and with a low glycemic index (see Chapter 16 of The Masters Athlete or http://www.glycemicindex.com ). A high percentage of this ...
Defective acute regulation of hepatic glycogen synthase by glucose and insulin, caused by severe insulin deficiency, can be corrected in adult rat hepatocytes in primary culture by inclusion of insulin, triiodothyronine, and cortisol in a chemically defined serum-free culture medium over a 3-day period (Miller, T. B., Jr., Garnache, A. K., Cruz, J., McPherson, R. K., and Wolleben, C. (1986) J. Biol. Chem. 261, 785-790). Using primary cultures of hepatocytes isolated from normal and diabetic rats in the same serum-free chemically defined medium, the present study addresses the effects of cycloheximide and actinomycin D on the chronic actions of insulin, triiodothyronine, and cortisol to facilitate the direct effects of glucose on the short-term activation of glycogen synthase. The short-term presence (1 h) of the protein synthesis blockers had no effect on acute activation of glycogen synthase by glucose in primary hepatocyte cultures from normal rats. Normal cells maintained in the presence of
After your workout you want to replenish with carbohydrates, not the grain and bread variety, but a shake, smoothie, protein bar, anything that is not too heavy for the stomach. The first 30 minutes after a workout are crucial for replenishing! This is what will prepare you for the next workout later that day or tomorrows. If you wait past that time the muscle glycogen synthesis is deceased, even up to 66%. What this means is that if you wait too long on carbohydrate intake then you will reduce muscle glycogen storage and increase risk of injury. Working out is a balance of effort and fuel. If you are not refueling your body you will not be able to work out later, and you want the energy to burn the body fat. Muscles burn body fat and you need complex carbohydrates to work the muscles for future workouts. Complex carbohydrates are found in grains, fruits, vegetables, beans, and milk. My ideal recovery snack or refuel is a veggie juice or shake, something in a liquid form. Find out what is ...
We examined the effects of whey versus collagen protein on skeletal muscle cell signaling responses associated with mitochondrial biogenesis and protein synthesis in recovery from an acute training session completed with low carbohydrate availability. In a repeated-measures design (after adhering to a 36-hr exercise-dietary intervention to standardize preexercise muscle glycogen), eight males completed a 75-min nonexhaustive cycling protocol and consumed 22 g of a hydrolyzed collagen blend (COLLAGEN) or whey (WHEY) protein 45 min prior to exercise, 22 g during exercise, and 22 g immediately postexercise. Exercise decreased (p , .05) muscle glycogen content by comparable levels from pre- to postexercise in both trials (≈300-150 mmol/kg·dry weight). WHEY protein induced greater increases in plasma branched chain amino acids (p = .03) and leucine (p = .02) than COLLAGEN. Exercise induced (p , .05) similar increases in PGC-1α (fivefold) mRNA at 1.5 hr postexercise between conditions, although no ...
for the analysis of glycogen in the tissue extracts. A biopsy technique was developed to remove between 5 and 10 mg of foot tissue in Amblema plicata plicata. The survival rate did not differ between biopsied and non-biopsied mussels during a 581-d observation period, demonstrating that the biopsy technique Mill allow nonlethal evaluation of the physiological condition of individual mussels through measurement of changes in contaminant, genetic, and biochemical indicators in tissue. We also modified the standard alkaline digestion and phenol-sulfuric acid analysis of glycogen for use on the small samples of biopsied tissue and to reduce analysis time and cost. We present quality control data, including method detection limits and estimates of precision and bias. The modified analytical method is rapid and accurate and has a method detection limit of 0.014 mg glycogen. Glycogen content in the biopsied samples was well above the method detection limit; it ranged from 0.09 to 0.36 mg, indicating ...
FUNCTION: [Summary is not available for the mouse gene. This summary is for the human ortholog.] The protein encoded by this gene, liver glycogen synthase, catalyzes the rate-limiting step in the synthesis of glycogen - the transfer of a glucose molecule from UDP-glucose to a terminal branch of the glycogen molecule. Mutations in this gene cause glycogen storage disease type 0 (GSD-0) - a rare type of early childhood fasting hypoglycemia with decreased liver glycogen content. [provided by RefSeq, Dec 2009 ...
By John C. Hill, and Iñigo San Millán DOI: 10.3810/psm.2014.09.2075 Abstract: Glycogen storage is essential for exercise performance. The ability to assess…
BLOOD SUGAR CONTROL - Honey may promote better blood sugar control. Proper fueling of the liver is central to optimal glucose metabolism during sleep and exercise. Honey is the ideal liver fuel because it contains a nearly 1:1 ratio of fructose to glucose. Fructose unlocks the enzyme from the liver cells nucleus that is necessary for the incorporation of glucose into glycogen (the form in which sugar is stored in the liver and muscle cells). An adequate glycogen store in the liver is essential to supply the brain with fuel when we are sleeping and during prolonged exercise. When glycogen stores are insufficient, the brain triggers the release of stress hormones--adrenalin and cortisol--in order to convert muscle protein into glucose. Repeated metabolic stress from cortisol produced when less than optimal liver glycogen stores are available during sleep, leads over time, to impaired glucose metabolism, insulin resistance, diabetes, and increased risk for cardiovascular disease and obesity. ...
1. HuZL, ParkCA, WuXL, ReecyJM (2013) Animal QTLdb: an improved database tool for livestock animal QTL/association data dissemination in the post-genome era. Nucleic Acids Research 41: D871-D879.. 2. RenJ, MaoH, ZhangZ, XiaoS, DingN, et al. (2011) A 6-bp deletion in the TYRP1 gene causes the brown colouration phenotype in Chinese indigenous pigs. Heredity (Edinb) 106: 862-868.. 3. RubinCJ, ZodyMC, ErikssonJ, MeadowsJR, SherwoodE, et al. (2010) Whole-genome resequencing reveals loci under selection during chicken domestication. Nature 464: 587-591.. 4. RubinCJ, MegensHJ, Martinez BarrioA, MaqboolK, SayyabS, et al. (2012) Strong signatures of selection in the domestic pig genome. Proc Natl Acad Sci U S A 109: 19529-19536.. 5. AnderssonL, GeorgesM (2004) Domestic-animal genomics: deciphering the genetics of complex traits. Nat Rev Genet 5: 202-212.. 6. GeorgesM (2007) Mapping, fine Mapping, and molecular dissection of quantitative trait loci in domestic animals. Annu Rev Genomics Hum Genet 8: ...
Carbohydrate Loading. Carbohydrates are the bodys primary source of energy during high intensity exercise. Upon consumption, carbohydrates are broken down to glucose and metabolized for energy. Unused glucose is stored as glycogen in the liver and muscles. After the body has utilized carbohydrate reserves, glycogen is synthesized back into glucose to be used as the alternative source of energy. It is upon this premise that carbo-loading is practiced to improve and sustain athletic performance.. Carbo-loading is the super-compensation of glycogen stores. It is the expectation of carbo-loading that the excess glucose will be converted to glycogen and stored in the liver and muscles. This over abundance of glycogen stores will become the readily available fuel source. Benefits of Carbo-loading. Because glycogen stores are typically not abundant, energy is often halted upon utilization. Thus, an athlete is said to have hit the wall. Carbo-loading maximizes the bodys ability to store ...
Hi, My question concerns the relationship between muscle glycogen liver glycogen and ketosis. Particularly, I am wondering if there is a way to have f
TY - JOUR. T1 - 1H NMR detection of lactate and alanine in perfused rat hearts during global and low pressure ischemia. AU - Zhao, P.. AU - Storey, C. J.. AU - Babcock, E. E.. AU - Malloy, C. R.. AU - Sherry, A. D.. PY - 1995. Y1 - 1995. N2 - A spin-echo method is presented for obtaining high resolution, 13C coupled, proton spectra of lactate and alanine in intact, beating rat hearts. All hearts were depleted of glycogen prior to prolonged perfusion with either 10 mM unenriched glucose or [1-13C]glucose to restore glycogen. These two groups of hearts were then examined by 1H NMR during prolonged global (zero flow) or low pressure (low flow) ischemia. During global ischemia, lactate was derived from both glucose and glycogen, with endogenous glycogen contributing twice as much lactate as exogenous glucose. During low perfusion pressure ischemia, however, lactate was derived exclusively from exogenous glucose. The entire pool of lactate (both 12C and 13C) was visible by NMR in intact, glucose ...
BioAssay record AID 318590 submitted by ChEMBL: Elevation in glycogen level in fasting BALB/c mouse at 5.70 mg/kg, ip after 3 hrs.
Differentially expressed marker genes and glycogen levels in pectoralis major of Ross308 broilers with wooden breast syndrome indicates stress, inflammation and hypoxic conditions ...
GUERRA, Isabela; SOARES, Eliane de Abreu and BURINI, Roberto Carlos. Nutritional aspects of competitive soccer. Rev Bras Med Esporte [online]. 2001, vol.7, n.6, pp.200-206. ISSN 1517-8692. http://dx.doi.org/10.1590/S1517-86922001000600003.. Soccer playing involves intermittent exercises the physical intensities of which depend upon the player line up in the field, the importance of the game, and competitor excellence. This review aims at describing the major metabolic impacts on these physical efforts and their nutritional implications for performance purposes. Soccer players usually spend approximately 1360 kcal each game, with a 5% decrease in the second half of the game. Glycogen reserves modulate strength and length of movements. Elite players deplete from 20% to 90% of their glycogen level during a match according to their physical conditioning, exercise intensity, environmental temperature, and pre-competition dietary intake. Body dehydration and hyperthermia accelerate glycogen depletion ...
The group directed by Prof. Guinovart is involved in several projects on glycogen metabolism and its dysfunctions in diabetes and Lafora disease. Studies on glycogen metabolism have allowed the identification of many enzymes and intermediate metabolites involved in the synthesis and degradation of this polysaccharide. However, new factors and processes that participate in glycogen regulation are constantly being discovered. Moreover, data on the mechanisms of control in distinct organs and in diverse physiological conditions are incomplete.
TY - JOUR. T1 - The hormonal control of glycogen metabolism. T2 - The amino acid sequence at the phosphorylation site of protein phosphatase inhibitor-1. AU - Cohen, Philip. AU - Rylatt, Dennis B.. AU - Nimmo, Gillian A.. PY - 1977/4/15. Y1 - 1977/4/15. UR - http://www.scopus.com/inward/record.url?scp=0017407844&partnerID=8YFLogxK. U2 - 10.1016/0014-5793(77)80147-6. DO - 10.1016/0014-5793(77)80147-6. M3 - Article. C2 - 193727. AN - SCOPUS:0017407844. VL - 76. SP - 182. EP - 186. JO - FEBS Letters. JF - FEBS Letters. SN - 0014-5793. IS - 2. ER - ...
The Metabolic Disorders Drugs market continues to grow steadily, immune to recessions and economic setbacks, thanks to changing lifestyles and the increasing number of working individuals in society. With constant and frequent innovations, the Metabolic Disorders Drugs market share is expected to continue on a growth trajectory for the next 5 years. A well-equipped market report can help those involved in the business tide over major hurdles in the business and achieve sustainable growth.. A rise in consumer disposable income along with improved living standards, particularly in developing countries is expected to fuel the Metabolic Disorders Drugs market demand. Developed countries are also expected to witness growth in the Glycogen Metabolism Disease Drug, Lipid Metabolism Disease Drug, Amino Acid Metabolism Drug, Other segments over the foreseeable future. This growth may be primarily attributed to high R&D developments and the introduction of advanced and innovative products.. Keep up with ...
We constantly tell bodybuilders about the muscle-building benefits of protein. It plays a direct role in muscle development by providing the body with amino acids. However, looking at the larger picture, muscle growth is not solely dependent on protein consumption. Carbohydrate consumption also plays an active role. In fact, the amount of carbohydrates stored inside muscles - called muscle glycogen - can determine whether or not muscles remain in an anabolic, or muscle-building, state. How vital are well-stocked glycogen stores? Protein intake above and beyond what reputable nutritionists say is enough wont boost muscle mass if glycogen stores are too low. On the other hand, if glycogen stores are full, chances of faster recovery and improved growth markedly increase.. So, why not simply load up on carbs in hopes of getting huge? Because consuming too many carbs creates the potential of increasing bodyfat. Taking steps to ensure that carbs are stored in muscles rather than as fat is half the ...
If you deplete your glycogen stores during your climbing session, it doesnt have to mean that you have to practice bad technique in the process. Neither does it have to mean that youre putting yourself at high risk for injury. My approach in gym training is to start with routes I can complete easily as a sort of warm-up, work up to more difficult ones until I peak at the most difficult routes I want to try to send until Im clearly depleted, then finally resort back to climbing the easy routes again whose sequences I have well established until Im physically drained. So, Id end with routes involving technique I dont have to put much effort into. I have those engrams so well established that I will still practice good technique on them, and I simultaneously continue to challenge myself to focus on the right things (center of gravity in relation to base of support, driving up with the legs while maintaining optimum posture for the moves, etc ...
During long periods of starvation, after the liver and muscle glycogen stores have been depleted, the body must rely on lipolysis, the breakdown of triglycerides stored in adipose tissue, for energy production. Triglycerides are composed of a 3 carbon glycerol backbone with 3 chains of fatty acids attached, one to each carbon. During lipolysis, hormone…
Save 27% Clif Bar - Builders Protein Bar Vanilla Almond 12 Bars Builders Protein Bar Low Glycemic | Non-GMO Ingredient Sources 20g of Complete Protein, with Essential Amino Acids to Help Repair and Build Muscle Carbohydrates to Help Replenish Your Muscle Glycogen Stores After a Workout Vitamins and Minerals to Support Protein Metabolism Fitness is Built™ Youre not done. Youre a work in progress, building toward something great. Thats why we made CLIF Builders® - the great-tasting protein bar that makes every ingredient count - so you can get the most out of your workout.
L-Glutamine Powder Free Form Amino Acid (Hypoallergenic) 200 grams L-glutamine is important for the development of enterocytes, a type of cell that is plentiful in the epithelial lining of the gastrointestinal tract. L-glutamine can help conserve muscle glycogen stores, stimulate growth hormone production, support neuronal health, and cross the blood-brain barrier where the brain uses it for fuel.* Free form amino acid, high purity, well tolerated. Suggested Use: As a dietary supplement, 1 teaspoon (approx. 4.7 grams) in water one to three times daily before meals, or as directed by a healthcare practitioner. Serving Size 1 teaspoon (4.7 g) Servings per container 42 Amount per serving: L-Glutamine 4.7 g This nutrient is of the highest quality and purity obtainable, free of all common allergens (antigens), and does not contain preservatives, diluents, or artificial additives. Keep in a cool, dry place, tightly capped.