Search Results
Results 601 - 650 of 1063
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Watt Matthew J - - 2003
Hormone-sensitive lipase (HSL) catalyzes the hydrolysis of intramuscular triacylglycerols (IMTGs), but HSL regulation is poorly understood in skeletal muscle. The present study measured human skeletal muscle HSL activity at rest and during 120 min of cycling at 60% of peak O2 uptake. Several putative HSL regulators were also measured, including ...
Noland Robert C - - 2003
In rodents, acute exercise increases skeletal muscle uncoupling protein (UCP) gene expression and is associated with elevations in serum nonesterified fatty acids (NEFA). To test whether contractions increase UCP mRNA levels in humans, vastus lateralis biopsies were obtained 1 hour postexercise from untrained and trained subjects and analyzed for UCP-2 ...
Tarnopolsky Mark - - 2003
Animal studies have shown that supra-physiological creatine monohydrate (Cr-mH) supplementation for 3 months reduced skeletal muscle creatine transporter (CRT) content. The doses of Cr-mH (1-2 g/kg/day) used in these studies were between 5 and 10 times those usually used in human studies, and it is unclear whether a down-regulation of ...
Pilegaard Henriette - - 2003
Endurance exercise training induces mitochondrial biogenesis in skeletal muscle. The peroxisome proliferator activated receptor co-activator 1alpha (PGC-1alpha) has recently been identified as a nuclear factor critical for coordinating the activation of genes required for mitochondrial biogenesis in cell culture and rodent skeletal muscle. To determine whether PGC-1alpha transcription is regulated ...
Musi N - - 2003
Physical exercise increases muscle glucose uptake, enhances insulin sensitivity and leads to fatty acid oxidation in muscle. The AMP-activated protein kinase (AMPK) is an energy-sensing enzyme that is strongly activated during muscle contraction due to acute decreases in ATP/AMP and phosphocreatine/creatine ratios. Accumulating evidence suggests that AMPK plays an important ...
Perez Andrea C - - 2003
Several different exercise regimens varied in the severity of tissue damage induced. Therefore, this study investigated the effects of a single bout of exercise versus endurance training in heart and skeletal muscles with different predominant fiber types on indices of mitochondrial, endoplasmic reticulum (ER) integrity and protein degradation. Male Wistar ...
Williamson D - - 2003
The purpose of this investigation was to examine the activation (phosphorylation) and total protein content of MAPK signalling cascade proteins (ERK 1/2, p90RSK, Mnk 1, eIF4E, p38 MAPK, JNK/SAPK, MKP 1) at rest and following exercise, in sedentary young and old men. Eight young (22 +/- 1 years; YM) and ...
Lloyd Pamela G - - 2003
Angiogenesis occurs in skeletal muscle in response to exercise training. To gain insight into the regulation of this process, we evaluated the mRNA expression of factors implicated in angiogenesis over the course of a training program. We studied sedentary control (n = 17) rats and both sedentary (n = 18) ...
Zambon Alexander C - - 2003
Skeletal muscle remodeling is a critical component of an organism's response to environmental changes. Exercise causes structural changes in muscle and can induce phase shifts in circadian rhythms, fluctuations in physiology and behavior with a period of around 24 hours that are maintained by a core clock mechanism. Both exercise-induced ...
Irrcher Isabella - - 2003
Behavioural and hereditary conditions are known to decrease mitochondrial volume and function within skeletal muscle. This reduces endurance performance, and is manifest both at high- and low-intensity levels of exertion. A programme of regular endurance exercise, undertaken over a number of weeks, produces significant adaptations within skeletal muscle such that ...
Stein T Peter - - 2003
PURPOSE OF REVIEW: In response to decreased usage, skeletal muscle undergoes adaptive reductive remodeling due to the decrease in tension on the weight bearing components of the musculo-skeletal system. This response occurs with uncomplicated disuse (e.g. bed rest, space flight), as a secondary consequence of several widely prevalent chronic diseases ...
Steensberg Adam - - 2003
Cytokines such as interleukin (IL)-6 are proteins, which were originally discovered within the immune system. Recent studies, however, demonstrate that IL-6 is produced by, and released from contracting skeletal muscles during exercise. This release occurs in the absence of muscle damage and is related to both contraction per se and ...
Hargreaves Mark - - 2003
The importance of nutrition, in combination with appropriate training, for successful exercise performance has been recognised for many years. Considerable emphasis has rightly focused on energy, carbohydrate and fluid balance, and nutritional strategies are designed to prevent the well documented ergolytic effects of carbohydrate depletion and dehydration on endurance exercise ...
Kubo Hajime - - 2003
INTRODUCTION: Exercise training induces significant changes in the performance of skeletal muscle. PURPOSE: To determine whether changes in the gene expression of rat hind-limb muscle sarcoplasmic reticulum Ca2+ -ATPase isoforms (SERCA1a and SERCA2a) in response to either moderate- or high-intensity exercise training underlie the functional remodeling. METHODS: SERCA1a and SERCA2a ...
Fehrenbach E - - 2003
Microarray analysis offers a set of analytical platforms that provide rapid, affordable and substantial information at the DNA, RNA or protein level. It enables the analysis of thousands of genes simultaneously in a parallel manner across samples derived from various biological sources and treatment regimens. This development became possible as ...
Zinna Erin M - - 2003
The objective is to summarize the findings from recent (June 2001-2002) studies that have examined the potential benefits of exercise training for the treatment of wasting associated with sarcopenia, cancer, chronic renal insufficiency, rheumatoid arthritis, osteoarthritis and HIV. In many clinical conditions, protein wasting and unintentional weight loss are predictors ...
McClung J M - - 2003
The role of creatine supplementation in altering the physiological parameters regulating cardiac muscle's functional capacity through the initiation of cardiac hypertrophy and altered contractile protein expression has not been determined. The purpose of this study was to determine the effect of creatine supplementation, with and without exercise stress, on physiological ...
Hameed M - - 2003
The mRNA expression of two splice variants of the insulin-like growth factor-I (IGF-I) gene, IGF-IEa and mechano growth factor (MGF), were studied in human skeletal muscle. Subjects (eight young, aged 25-36 years, and seven elderly, aged 70-82 years) completed 10 sets of six repetitions of single legged knee extensor exercise ...
Baar Keith - - 2002
Endurance exercise induces increases in mitochondria and the GLUT4 isoform of the glucose transporter in muscle. Although little is known about the mechanisms underlying these adaptations, new information has accumulated regarding how mitochondrial biogenesis and GLUT4 expression are regulated. This includes the findings that the transcriptional coactivator PGC-1 promotes mitochondrial ...
Vassilakopoulos T - - 2003
In this study, we evaluated the differential influence of chronic treadmill training (30 m/min, 15% incline, 1 h/day, 5 days/wk) on nitric oxide (NO) production and NO synthase (NOS) isoform expression as well as 3-nitrotyrosine formation (footprint of peroxynitrite) both in limb (gastrocnemius) and ventilatory (diaphragm) muscles. A group of ...
Phillips S M - - 2002
Resistance training changes the balance of muscle protein turnover, leading to gains in muscle mass. A longitudinal design was employed to assess the effect that resistance training had on muscle protein turnover in the fed state. A secondary goal was investigation of the potential interactive effects of creatine (Cr) monohydrate ...
Wojtaszewski Jørgen F P - - 2002
During prolonged, low intensity exercise, the type of substrate utilized varies with time. If 5' AMP-activated protein kinase (AMPK) regulates muscle metabolism during exercise, signaling through AMPK would be expected to change in concordance with changes in substrate utilization. Six healthy, young males cycled (approximately 45% VO(2peak)) until exhaustion (approximately ...
Febbraio Mark A - - 2002
Physical exercise results in the appearance of heat shock protein (HSP) 72 in the circulation that precedes any increase in gene or protein expression in contracting skeletal muscle. In rodents, exercise increases liver HSP72 expression and the hepatosplanchnic viscera are known to release many acute phase proteins. In the present ...
Nielsen Jakob N - - 2003
5'-AMP-activated protein kinase (AMPK) has been proposed to be a pivotal factor in cellular responses to both acute exercise and exercise training. To investigate whether protein levels and gene expression of catalytic (alpha(1), alpha(2)) and regulatory (beta(1), beta(2), gamma(1), gamma(2), gamma(3)) AMPK subunits and exercise-induced AMPK activity are influenced by ...
Watt Matthew J - - 2002
Intramuscular triacylglyerols (IMTGs) represent a potentially important energy source for contracting human skeletal muscle. Although the majority of evidence from isotope tracer and (1)H-magnetic resonance spectroscopy (MRS) studies demonstrate IMTG utilization during exercise, controversy regarding the importance of IMTG as a metabolic substrate persists. The controversy stems from studies that ...
Gosmanov Aidar R - - 2002
This study investigated exercise adaptation of signaling mechanisms that control Na(+)-K(+)-2Cl(-) cotransporter (NKCC) activity in rat skeletal muscle. An acute bout of exercise increased total and NKCC-mediated (86)Rb influx. Inhibition of extracellular signal-regulated kinase (ERK) activation abolished the exercise-induced NKCC upregulation. Treadmill training (20 m/min, 20% grade, 30 min/day, 5 ...
Groskreutz Jon J JJ Program in Physical Therapy, Department of Physical Medicine and Rehabilitation, School of Medicine, University of Minnesota, Minneapolis, MN 55455, - - 2002
The purpose of the present study was to examine the effects of aging, inactivity and weight-bearing exercise on fast-twitch single Type IIB skeletal muscle fibers from the superficial region of the lateral head of the gastrocnemius (Type IIB fibers). Specifically, this study compared the biochemical properties of Type IIB fibers ...
Jones Terry E - - 2003
Previous studies have indicated that exercise acutely induces large increases in uncoupling protein-3 (UCP3) in skeletal muscle, whereas endurance training results in marked decreases in muscle UCP3. Because UCP3 expression appears to be regulated by the same mechanism as other mitochondrial constituents, it seemed unlikely that exercise would result in ...
Radák Zsolt - - 2002
Regular physical exercise retards a number of age-associated disorders, in spite of the paradox that free radical generation is significantly enhanced with exercise. Eight weeks of treadmill running resulted in nearly a 40% increase in maximal oxygen uptake in both middle-aged (20-month-old) and aged (30-month-old) rats. The age-associated increase in ...
Tipton Kevin D KD Metabolism Unit, Shriners Hospitals for Children, Galveston, Texas 77550, USA. - - 2003
The purpose of this study was to determine if the acute anabolic muscle response to resistance exercise and essential amino acids (EAA) reflects the response over 24 h. Seven subjects participated in the following two 24-h studies: 1) resting (REST) and 2) rest plus resistance exercise and consumption of EAA ...
Perez Andrea C - - 2002
Nitric oxide (NO), a short-lived vasoactive substance that has multiple physiological functions, is also involved in skeletal muscle physiology. This work examines the levels of nitrate (the metabolic end-product of NO) in muscle and plasma after different exercise protocols: namely acute, eccentric, cardiac stress and training. Plasma nitrate levels were ...
Hargreaves Mark - - 2002
Skeletal muscle, as a consequence of its mass and great capacity for altered metabolism, has a major impact on whole-body metabolic homeostasis and is capable of remarkable adaptation in response to various physiological stimuli, including exercise and dietary intervention. Exercise-induced increases in skeletal muscle mRNA levels of a number of ...
Pösö A R - - 2002
In response to stress, cells synthesise heat shock proteins (HSP) to maintain protein homeostasis. To study whether exercise and training induce expression of HSP72 in the middle gluteal muscle, 10 Finnhorses performed a submaximal 60 min exercise test on a treadmill. Test A was performed after 3 months of training, ...
Steensberg Adam - - 2002
The aim of the present study was to examine whether IL-6 and TNF-alpha are expressed in, and released from, human skeletal muscle during exercise. We hypothesized that the skeletal muscle will release IL-6, but not TNF-alpha, during exercise because of previous observations that TNF-alpha negatively affects glucose uptake in skeletal ...
Ikeda Shinobu - - 2002
Exercise increases utilization of lipids and carbohydrates in skeletal muscles. After exercise, replenishment of glycogen and triglyceride occurs in skeletal muscles. To elucidate the mechanism of lipid filling effect after exercise training, expression patterns of genes related to triglyceride synthesis were examined under several exercise conditions. Mice exercised by 2-week ...
Terada Shin - - 2002
We previously reported that the peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1) mRNA in rat epitrochlearis muscle was increased after swimming exercise training. In the present study, we demonstrated further that PGC-1 mRNA expression in the epitrochlearis muscle of 4-5-week-old male Sprague-Dawley rats was increased after a 6-h acute bout of ...
Féasson L - - 2002
The molecular events by which eccentric muscle contractions induce muscle damage and remodelling remain largely unknown. We assessed whether eccentric exercise modulates the expression of proteinases (calpains 1, 2 and 3, proteasome, cathepsin B+L), muscle structural proteins (alpha-sarcoglycan and desmin), and the expression of the heat shock proteins Hsp27 and ...
Niess A M - - 2002
Previous research revealed an increased expression of HSP72 in leukocytes after vigorous endurance exercise. We questioned whether more intensive but shorter exercise also induces leukocyte HSP72 synthesis. To delineate the role of reactive oxygen species (ROS) in exercise-related HSP72 induction, we additionally examined the effect of RRR-alpha-tocopherol (alpha-toc) on HSP72 ...
Mitsui Takao - - 2002
Corticosteroid myopathy is a major clinical problem in patients undergoing chronic corticosteroid treatment and shows insidious and progressive muscle atrophy in proximal limbs. Although several mechanisms underlying the pathophysiology of muscle injury have been postulated, precise pathogenesis is still not clear. We evaluated the mitochondrial functions in patients receiving corticosteroids ...
Hubley-Kozey Cheryl L - - 2002
OBJECTIVES: To evaluate the relative activation amplitudes from 3 abdominal and 2 trunk extensor muscle sites of persons with low back pain (LBP) performing the pelvic-tilt, the abdominal-hollowing, and level 1 of the trunk stability test (TST) exercises and to compare the activation amplitudes among muscle sites and exercises. DESIGN: ...
Vincent Heather K - - 2002
We tested the hypothesis that chronic endurance exercise is associated with the recruitment of four major upper airway muscles (genioglossus, digastric, sternohyoid, and omohyoid) and results in an increased oxidative capacity and a fast-toward-slow shift in myosin heavy chain (MHC) isoforms of these muscles. Female Sprague-Dawley rats (n = 8; ...
Lemon Peter W R - - 2002
Rather than the age-old debate regarding overall protein and amino acid needs of athletes, this paper focuses on the importance of timing and type of protein and amino acid ingestion relative to both muscle growth and exercise performance. Evidence discussed comes from definitive measurement techniques including net protein balance determinations ...
Milne Kevin J - - 2002
Exercise induces expression of the protective heat shock protein, HSP70, in striated muscle. To characterize the relationship between induction of this protein and exercise intensity in muscles exhibiting different recruitment patterns, male Sprague-Dawley rats were assigned to a sedentary control or one of seven exercise groups for which treadmill running ...
Allen David L - - 2002
The increasing availability of molecular biological techniques has allowed exercise researchers to examine the molecular mechanisms underlying exercise performance and adaptation. We discuss three molecular approaches that can evaluate the role of individual genes in the exercise response, and could provide a foundation for more effective exercise regimens for humans.
Gavin T P - - 2002
We investigated the vascular endothelial growth factor (VEGF) receptor [fms-like-tyrosine kinase (Flt-1 and fetal liver kinase-1 (Flk-1)] response to acute exercise. In female Wistar rats, the VEGF receptor messenger RNA (mRNA) response to a single acute exercise bout was examined using semi-quantitative Northern blot from the left gastrocnemius muscles at ...
Tunstall Rebecca J - - 2002
The effects of a single bout of exercise and exercise training on the expression of genes necessary for the transport and beta-oxidation of fatty acids (FA), together with the gene expression of transcription factors implicated in the regulation of FA homeostasis were investigated. Seven human subjects (3 male, 4 female, ...
Fielding Roger A - - 2002
Exercise and physical activity increase energy expenditure up to 10-fold. This brief review will focus on the effect of exercise on protein requirements. Evidence has accumulated that amino acids are oxidized as substrates during prolonged submaximal exercise. In addition, studies have determined that both endurance and resistance training exercise increase ...
Durante Paula E - - 2002
The effects of endurance training on the response of muscle AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) to moderate treadmill exercise were examined. In red quadriceps, there was a large activation of alpha 2-AMPK and inactivation of ACC in response to exercise. This response was greatly reduced after training, ...
Sakamoto Kei - - 2002
Physical exercise is a significant stimulus for the regulation of multiple metabolic and transcriptional processes in skeletal muscle. For example, exercise increases skeletal muscle glucose uptake, and, after exercise, there are increases in the rates of both glucose uptake and glycogen synthesis. A single bout of exercise can also induce ...
Park Haejoe - - 2002
Changes in the concentration of malonyl-CoA in many tissues have been related to alterations in the activity of acetyl-CoA carboxylase (ACC), the rate-limiting enzyme in its formation. In contrast, little is known about the physiological role of malonyl-CoA decarboxylase (MCD), an enzyme responsible for malonyl-CoA catabolism. In this study, we ...
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