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Results 701 - 750 of 816
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Fridén J - - 1985
Distribution of glycogen particles in semithin and ultrathin sections of biopsy samples from human muscles subjected to either short- or long-term running were investigated using PAS and Periodic Acid-ThioSemiCarbazide-Silver Proteinate (PA-TSC-SP) staining methods. Glycogen particles were predominantly found immediately under the sarcolemma or aligned along the myofibrillar I-band. After long-term ...
Vøllestad N K - - 1984
Glycogen depletion of muscle fibre types I, II A, II AB and II B was studied using a histochemical method to quantify glycogen content in individual fibres. The reliability was examined in 29 muscle biopsies, in which total glycogen content was compared to average periodic acid Schiff (PAS) stain intensity ...
Björkman O - - 1984
The aim of the present study was to examine the influence of glucose and fructose ingestion on the capacity to perform prolonged heavy exercise. Eight well-trained healthy volunteers exercised on a bicycle ergometer at 68 +/- 3% of their VO2 max until exhaustion, on three occasions, with 8-day intervals. During ...
Coyle E F - - 1984
Prolonged exercise in the fasted state frequently results in a lowering of blood glucose concentration, and when the intensity is moderate (i.e. 60-80% of VO2 max), muscle often becomes depleted of glycogen. The extent to which carbohydrate feedings contribute to energy production, and their effectiveness for improving endurance during prolonged ...
Constable S H - - 1984
This study was undertaken to determine whether glycogen resynthesis can occur in glycogen-depleted muscles in response to glucose feeding during prolonged exercise. Rats were exercised for 40 min with a treadmill running program designed to deplete muscle glycogen. One group was studied immediately after the glycogen-depletion exercise. A second group ...
Kono N - - 1984
A 26-year-old girl with muscle phosphorylase deficiency had exercise intolerance and experienced an occasional "second wind" phenomenon. Muscle glycogen concentration was about three times the normal level, whereas each glycolytic intermediate below the phosphorylase step was equivalent to only 10% of a normal level. Semi-ischemic forearm exercise tests disclosed no ...
Rowland N - - 1984
The food intake and growth of male and female golden hamsters, with and without access to running wheels, were measured under several conditions. These included different seasons, photoperiods and diets. Chow-fed males in wheels invariably had slowed weight gain and showed little hyperphagia relative to sedentary controls. One group of ...
Pierce G N - - 1984
This study investigated alterations in glycogen, catecholamines, and the function of various subcellular membranes of the heart after exhaustive swimming in rats. The rats were exhausted by daily exercise over 1, 3, or 7 consecutive days. Glycogen content of the heart and three selected skeletal muscles was depleted after a ...
Pilo B - - 1984
The pectoralis muscles of two groups of anaesthetized pigeons were exercised in vivo by electrical stimulation for periods of 1 h and 5 h respectively. There was no significant change from controls in the level of blood glucose in both groups. Blood lactate level was significantly higher in the exercised ...
Gollnick P D - - 1984
Carbohydrate is an important energy source during exercise. During short, heavy exercise it may be the only energy source for the working muscle and may be derived exclusively from the glycogen stores within the muscle fibers themselves. During prolonged, submaximal exercise the magnitude of the contribution that carbohydrate makes to ...
Derevenco P - - 1984
A mild 10 min exercise, induced by "in vivo" electrical stimulation of the rat gastrocnemius, causes decreases of the muscle glycogen content (G) and phosphorylase alpha activity (PA), and an increase of its overall glycolytic capacity (OGC); in the myocardium, PA decrease of liver glycogen were brought about by peripheral ...
Bhagyalakshmi A - - 1984
Healthy crabs (Oziotelphusa senex senex) were exposed to 3 concentrations of sumithion, with a control group over a 30-day period. The glycogen content of the hepatopancreas was depleted on acute exposure but was elevated after acclimatization. The glycogen phosphorylase activity was elevated on acute exposure, whereas phosphorylase activity decreased after ...
Matoba H - - 1984
Physical training induces adaptive changes in skeletal muscle. These changes are localised to the active muscle with their magnitude depending upon the nature, i.e. time and intensity, of the training regimen. The most notable changes are increased concentrations of mitochondria and glycogen. With endurance training there are major changes in ...
Kato S - - 1984
[3H]Mannose-labeled glycopeptides in the slices after partial hepatectomy were characterized by column chromatography using Sephadex G-50, DE-52 and Con A-Sepharose, and further by digestion with alpha-mannosidase and endo-beta-N-acetylglucosaminidase H. They contained both 'complex type' and 'high-mannose type' oligosaccharides. A higher proportion of 'complex type' oligosaccharides was contained in regenerating liver ...
Riedy M - - 1984
Biopsy samples from the vastus lateralis muscle (VLM) of man were examined for fiber composition at rest and at selected intervals during prolonged exercise ranging in intensity from 40% to 75% of the total body maximal oxygen uptake (VO2max) and one-min bouts of exercise at 150% VO2max. Because of the ...
James D E - - 1984
It is thought that exercise training in both man and the rat results in a protective effect against the depletion of carbohydrate stores during exercise (glycogen-sparing). However there has been no comprehensive study of the effects of training on glycogen anabolic and catabolic enzymes with liver or muscle. The aim ...
Guezennec C Y - - 1984
Previous studies have shown a decrease in plasma testosterone during prolonged physical exercise and 72 h fasting in rats. To determine whether this hormonal change has an influence upon energy metabolism, two experiments were carried out, in which the plasma levels of testosterone were elevated during prolonged physical exercise and ...
Mitsunami K - - 1984
To identify and characterize the border zone, anesthetized dogs were subjected to 1-hour occlusion of the left anterior descending coronary artery with (Group R) or without (Groups A and B) 2 hours of subsequent reperfusion. Histochemical analysis of glycogen distribution, biochemical determination of lactate and adenosine triphosphate (ATP), and ultrastructural ...
Tesch P A - - 1984
Five elite flatwater kayak paddlers were studied during indoor simulated 500 and 10,000-m races, with performance times of 2 and 45 min, respectively. Muscle biopsies were obtained from the midportion of m. deltoideus immediately pre and post exercise. Concentrations of adenosine triphosphate (ATP), creatine phosphate (CP), glucose, glucose-6-phosphate (G-6-P), glycogen, ...
Young K - - 1984
The effect of altering muscle glycogen on the ability of skeletal muscle to generate voluntary and electrically evoked isometric force following prolonged exercise has been investigated in five healthy male subjects. Measurements from the triceps surae were made at rest, and before and after prolonged exercise (uphill walking) at approximately ...
Weiner D A - - 1983
An integrated response to exercise must occur among the cardiovascular, pulmonary, and regional circulations. The increased oxygen inspired by the lungs must be transported through the circulation and taken up by the exercising muscles. The cardiovascular adaptations to maximal exercise include an increase in cardiac output (predominantly by a rise ...
Bogardus C - - 1983
In rats, muscle glycogen depletion has been associated with increased insulin action. Whether this also occurs in man has not been reported. After 4 d rest, 13 males (E Group) had a percutaneous muscle biopsy of the vastus lateralis muscle followed by a euglycemic clamp at plasma insulin congruent to ...
Young J C - - 1983
Muscle contractile activity results in an increase in glucose uptake rate that can persist for hours. This study was undertaken to determine the effect of carbohydrate repletion on reversal of an exercise-induced increase in glucose uptake. Rats were exercised by swimming. In rats studied 60 min after exercise, muscle glycogen ...
Jacobs I - - 1983
Severe skeletal muscle glycogen depletion has been previously reported for soldiers participating in field exercises. The purpose of the present study was to determine if the distribution of amplified food rations would reduce the extent of glycogen depletion during military field manoeuvres. Needle biopsy samples were obtained from the m. ...
Sherman W M - - 1983
The purpose of this study was to determine the effect of running a marathon and subsequent rest or exercise during a 7-day recovery period on muscle glycogen, glycogen synthase, hexokinase, and the activity of hexose monophosphate pathway enzymes. Ten well-trained runners were randomly assigned to either a postmarathon rest or ...
Dohm G L - - 1983
We recently observed that a 24-h fasted group of rats could run longer than an ad libitum fed control group before becoming exhausted. Because of the demonstrated importance of glycogen levels and free fatty acid availability during endurance exercise, we have investigated several parameters of carbohydrate and lipid metabolism in ...
Tarssanen L T - - 1983
We studied the serum potassium rise during a 30-min 100 W exercise test in 5 controls, 3 familial periodic paralysis (FPP) patients and their 2 symptom-less brothers. The controls showed a steep and high exercise response (the 10-min rise was 0.59 +/- 0.13 mmol/l and the maximal rise was 0.71 ...
Dohm G L - - 1983
Prolonged exercise increased the concentrations of the hexose phosphates and phosphoenolpyruvate and depressed those of fructose 1,6-bisphosphate, triose phosphates and pyruvate in the liver of the rat. Since exercise increases gluconeogenic flux, these changes in metabolite concentrations suggest that metabolic control is exerted, at least, at the fructose 6-phosphate/fructose 1,6-bisphosphate ...
Heigenhauser G J - - 1983
Five male subjects performed two graded exercise studies, one during control conditions and the other after reduction of muscle glycogen content by repeated maximum exercise and a high fat-protein diet. Reduction in preexercise muscle glycogen from 59.1 to 17.1 mumol X g-1 (n = 3) was associated with a 14% ...
Miller J M - - 1983
This study evaluated the effectiveness of pre-exercise glycerol feeding in protecting against development of hypoglycemia and sparing muscle glycogen during prolonged, intense exercise. Thirty minutes after ingesting either glycerol (1 gm X kg-1 body weight) or a placebo, 10 cyclists performed as much exercise on a cycle ergometer as they ...
Chasiotis D - - 1983
The regulation of glycogen phosphorylase and glycogen breakdown in human skeletal muscle has been investigated using the needle biopsy technique. Preliminary studies showed that the activity of phosphorylase in vitro was dependent upon the concentration of inorganic phosphate (Pi) used in the assay system. The Km of phosphorylase a for ...
Izzo G - - 1983
A double tracer experiment was performed in one normal subject and in one cirrhotic patient to better understand the tracer kinetics in the liver area during the first minute after injection. From a comparison of the time-activity curves obtained in each subject by subsequent iv administration of a nonextracted and ...
Marciniak M - - 1983
The purpose of this research was morphometric ultrastructure evaluation of the fibers in muscles taking part in the flight of pigeons forced to exercise after a long period of hypodynamia. It was found that following physical exercise, after 12 and 18 months of mobility limitation, there appeared marked qualitative and ...
Garetto L P - - 1983
Marked circadian fluctuations in skeletal muscle glycogen concentrations have previously been reported. The purpose of the present study was to estimate the influence of these rhythms on muscle glycogen metabolism during and after high-intensity treadmill exercise. Male Sprague-Dawley rats ran five 1-min sprints at 75 m min-1 interspersed by 1-3 ...
Skrinar G S - - 1982
Seven wheelchair-dependent endurance athletes (5 males, 2 females, mean age = 27 years, mean VO2 max = 2.01 1/min) consented to maximal and submaximal (SM) testing on a wheelchair ergometer for the purpose of determining aerobic capacity, plasma substrate concentration, and muscle glycogen utilization during prolonged exercise. Results from an ...
Juhlin-Dannfelt A C - - 1982
The purpose of this study was to determine whether beta-adrenergic receptor blockade inhibits glycogen utilization in rats during exercise. Propranolol (1 mg/kg body wt) completely blocked the glycogenolytic effect of a large dose of epinephrine given by injection but did not prevent glycogen breakdown in skeletal muscle or liver during ...
Chasiotis D - - 1982
The regulation of glycogenolysis in human muscle during isometric and dynamic exercise has been investigated. Total glycogen phosphorylase and synthase activities were unchanged during exercise. The fraction of phosphorylase in the alpha form at rest was estimated to be 20%, but the data indicate that the in vivo activity was ...
Ward G R - - 1982
1. The activity of pyruvate dehydrogenase in its active and inactive forms was measured in biopsy samples obtained from the vastus lateralis muscle of healthy subjects before and after exercise. 2. At rest, 40 +/- 4% (mean +/- SEM) of the enzyme was in the active form. 3. After progressive ...
Jansson E - - 1982
7 subjects were studied at rest and during a 6 min submaximal exercise (65% of VO2 max) on two occasions, the first preceded by a fat rich diet and the second by a carbohydrate rich diet. Oxygen uptake and respiratory exchange ratio (R) were measured at rest and heart rate ...
Hughes E F - - 1982
Nine male subjects performed continuous incremental exercise on a bicycle ergometer pedaling at 50 and 90 rpm in a normal glycogen state (NG) and at 50 rpm in a glycogen-depleted state (GD) to determine if alterations in pedaling frequency and muscle glycogen content would affect their "anaerobic thresholds." Ventilatory [T(vent)] ...
Poland J L - - 1982
Though glucocorticoids were previously implicated in the support of myocardial glycogen supercompensation after exercise, it was unclear why skeletal muscle glycogen did not simultaneously supercompensate since it was also exposed to the exercise-induced glucocorticoid increases. The current study shows that glucocorticoids differentially affect cardiac and skeletal muscle glycogen. Following dexamethasone ...
Young A J - - 1982
Substrate utilization during heavy [approximately 85% maximum O2 consumption (VO2max)] bicycle exercise was examined in eight low-altitude residents at sea level (SL) and after acute (2 h) and chronic (18 days) high-altitude (HA) exposure at 4,300 m. Mean VO2max was approximately 27% lower at acute HA than at SL and ...
Jacobs I - - 1982
The purpose of this study was to quantify the changes in selected intramuscular metabolites associated with non-oxidative energy metabolism after performance of the Wingate Test (WT), a widely used, exhaustive, 30-s cycle test of short-time muscular power. Muscle biopsies were taken from the m. vastus lateralis of nine female physical ...
Jonnalagadda S B - - 1982
To localise the controlling point of the glycolytic system, the temporal changes in concentrations of glycolytic intermediates have been analysed after addition of glycogen to a substrate-depleted yeast extract. Three sequential metabolic states are clearly observable: a transition state at which there is continuous accumulation of the intermediates before the ...
Hashimoto I - - 1982
The role of the adrenergic system in regulating glycogenolysis during exercise was studied in rats. Alterations in the adrenergic system were produced by injections of 6-hydroxydopamine (6-OHD), surgical removal of the adrenal medulla (ADMX), or the combination of ADMX and 6-OHD injection. Exercise was treadmill running at 22 m/min for ...
Fitts R H - - 1982
Alterations in the contractile and biochemical properties of fast and slow skeletal muscle were studied in rats following a prolonged swim to exhaustion. The exercise produced glycogen depletion (less than 1 mg/g tissue) in muscles representative of all three fiber types; the isometric contractile properties were altered in the 84% ...
Goldfarb A H - - 1981
The purpose of this investigation was to determine whether adenosine 3',5'-cyclic monophosphate (cAMP) content is increased in vivo in the heart as a result of exercise at a time when there is rapid cardiac glycogen utilization. Rats were run to exhaustion on a treadmill for a period of 164.5 +/- ...
Ivy J L - - 1981
The effect of a bout of exercise on glucose uptake and glycogen synthesis in skeletal muscle was examined using a perfused rat hindlimb preparation. Rats were subjected to a bout of swimming. The exercise stress was moderate as reflected in a reduction of muscle glycogen concentration of only 50%. Glucose ...
Bogardus C - - 1981
Eight untrained, obese females (greater than 30% body fat), ages 25-33 yr, were studied before, at 1 wk, and after 6 wk while taking either of two 830-kcal/d diets: carbohydrate-containing (CC) group (n = 4): 35% protein, 29% fat, 36% carbohydrate-restricted (CR) group (n = 4): 35% protein, 64% fat, ...
Sauerwein H P - - 1981
Influence of total parenteral nutrition and operation on alanine turnover and venous alanine concentration was determined in 5 patients with stomach carcinoma using single technique of U-14C alanine. Every patient served at his own control. In the postabsorptive state alanine turnover was 1.63 +/- 0.31 mgatC . min-1, not different ...
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