Read by QxMD icon Read

skeletal muscle and exercise

Clara Bien Peek, Daniel C Levine, Jonathan Cedernaes, Akihiko Taguchi, Yumiko Kobayashi, Stacy J Tsai, Nicolle A Bonar, Maureen R McNulty, Kathryn Moynihan Ramsey, Joseph Bass
Circadian clocks are encoded by a transcription-translation feedback loop that aligns energetic processes with the solar cycle. We show that genetic disruption of the clock activator BMAL1 in skeletal myotubes and fibroblasts increased levels of the hypoxia-inducible factor 1α (HIF1α) under hypoxic conditions. Bmal1(-/-) myotubes displayed reduced anaerobic glycolysis, mitochondrial respiration with glycolytic fuel, and transcription of HIF1α targets Phd3, Vegfa, Mct4, Pk-m, and Ldha, whereas abrogation of the clock repressors CRY1/2 stabilized HIF1α in response to hypoxia...
October 19, 2016: Cell Metabolism
Aaron J Done, Tinna Traustadóttir
The primary aim of this review is to summarize the current literature on the effects of acute exercise and regular exercise on nuclear factor erythroid 2-related factor 2 (Nrf2) activity and downstream targets of Nrf2 signaling. Nrf2 (encoded in humans by the NFE2L2 gene) is the master regulator of antioxidant defenses, a transcription factor that regulates expression of more than 200 cytoprotective genes. Increasing evidence indicates that Nrf2 signaling plays a key role in how oxidative stress mediates the beneficial effects of exercise...
October 14, 2016: Redox Biology
Matthew S Palmer, George Jf Heigenhauser, MyLinh Duong, Lawrence L Spriet
This study determined whether mild dehydration influenced skeletal muscle glycogen use, core temperature or performance during high-intensity, intermittent cycle-based exercise in ice hockey players vs. staying hydrated with water. Eight males (21.6 ± 0.4 yr, 183.5 ± 1.6 cm, 83.9 ± 3.7 kg, 50.2 ± 1.9 mL·kg(-1)·min(-1)) performed two trials separated by 7 days. The protocol consisted of 3 periods (P) containing 10 x 45-second cycling bouts at ~133% VO2max, followed by 135 seconds of passive rest. Subjects drank no fluid and dehydrated during the protocol (NF), or maintained body mass by drinking WATER...
October 21, 2016: International Journal of Sport Nutrition and Exercise Metabolism
Helena Lenasi, Markos Klonizakis
Diabetes mellitus (DM) is associated with cardiovascular complications. Impairment of glycemic control induces noxious glycations, an increase in oxydative stress and dearangement of various metabolic pathways. DM leads to dysfunction of micro and macrovessels, connected to metabolic, endothelial and autonomic nervous system. Thus, assessing vascular reactivity might be one of the clinical tools to evaluate the impact of harmful effects of DM and potential benefit of treatment; skin and skeletal muscle microcirculation have usually been tested...
October 18, 2016: Clinical Hemorheology and Microcirculation
Justin D La Favor, Gabriel S Dubis, Huimin Yan, Joseph D White, Margaret A M Nelson, Ethan J Anderson, Robert C Hickner
OBJECTIVE: The objectives of this study were to determine the impact of in vivo reactive oxygen species (ROS) on microvascular endothelial function in obese human subjects and the efficacy of an aerobic exercise intervention on alleviating obesity-associated dysfunctionality. APPROACH AND RESULTS: Young, sedentary men and women were divided into lean (body mass index 18-25; n=14), intermediate (body mass index 28-32.5; n=13), and obese (body mass index 33-40; n=15) groups...
October 20, 2016: Arteriosclerosis, Thrombosis, and Vascular Biology
Victor M Niemeijer, Ruud F Spee, Thijs Schoots, Pieter F F Wijn, Hareld M Kemps
The extent and speed of transient skeletal muscle deoxygenation during exercise onset in chronic heart failure (CHF) patients is related to impairments of local O2 delivery and utilization. This study examined the physiological background of submaximal exercise performance in 19 moderately impaired CHF patients (Weber class A, B, and C) compared with 19 matched healthy control (HC) subjects by measuring skeletal muscle oxygenation (SmO2) changes during cycling exercise. All subjects performed two subsequent moderate-intensity 6-minute exercise tests (bout 1 and 2) with measurements of pulmonary oxygen uptake kinetics, and SmO2 using near infrared (NIR) spatially resolved spectroscopy (SRS) at the vastus lateralis for determination of absolute oxygenation values, amplitudes, kinetics (mean response time for onset), and deoxygenation overshoot characteristics...
October 7, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Ikram Bezrati, Raouf Hammami, Mohamed Kacem Ben Fradj, Domenico Martone, Johnny Padulo, Moncef Feki, Anis Chaouachi, Naziha Kaabachi
Vitamin D is thought to regulate skeletal muscle function and boost physical performance. The aim of this study was to assess the relationship between vitamin D and physical performance in physically active children. This cross-sectional study included 125 children who practice football as a leisure activity. Plasma 25-hydroxyvitamin D (25-OHD) was assessed using a chemiluminescence immunoassay method. Vitamin D inadequacy was defined as 25-OHD < 20 ng/mL. Physical performance testing included measurements of muscle strength (maximal isometric contraction), jumping ability (vertical jump, standing broad jump, triple hop test), linear sprint (10 m and 20 m), and agility (9 × 4-m shuttle run)...
July 13, 2016: Applied Physiology, Nutrition, and Metabolism, Physiologie Appliquée, Nutrition et Métabolisme
Hye Jin Kim, Hae Min Yoon, Oran Kwon, Won Jun Lee
PURPOSE: Pueraria lobata/rehmannia glutinosa (PR) and exercise have been receiving a lot of attention from postmenopausal women, as a result of the side effects of estrogen replacement therapy. However, the effects of PR and exercise on fatty acid transporters (FATPs), which play essential role in fatty acid transport, have not been studied. In this study, we evaluated the effects of PR and aerobic exercise on FATP1, FABPpm and FAT/CD36 expression in ovariectomized rat skeletal muscles...
September 2016: Journal of Exercise Nutrition & Biochemistry
Sintip Pattanakuhar, Anchalee Pongchaidecha, Nipon Chattipakorn, Siriporn C Chattipakorn
Skeletal muscles play important roles in metabolism, energy expenditure, physical strength, and locomotive activity. Skeletal muscle fibre types in the body are heterogeneous. They can be classified as oxidative types and glycolytic types with oxidative-type are fatigue-resistant and use oxidative metabolism, while fibres with glycolytic-type are fatigue-sensitive and prefer glycolytic metabolism. Several studies demonstrated that an obese condition with abnormal metabolic parameters has been negatively correlated with the distribution of oxidative-type skeletal muscle fibres, but positively associated with that of glycolytic-type muscle fibres...
October 15, 2016: Obesity Research & Clinical Practice
Juquan Song, Melody R Saeman, Lisa A Baer, Anthony R Cai, Charles E Wade, Steven E Wolf
This study investigated microRNA and target gene profiles under different conditions of burn, bed rest, and exercise training. Male Sprague-Dawley rats (n = 48) were assigned to sham ambulatory, sham hindlimb unloading, burn ambulatory, or burn plus hindlimb unloading groups. Rats received a 40% TBSA scald burn or sham treatments and were ambulatory or hindlimb unloaded. Rats were further assigned to exercise or no exercise. Plantaris tissues were harvested on day 14 and pooled to analyze for microRNA and gene expression profiles...
September 28, 2016: Journal of Burn Care & Research: Official Publication of the American Burn Association
Arturo Figueroa, Alexei Wong, Salvador J Jaime, Joaquin U Gonzales
PURPOSE OF REVIEW: L-Citrulline, either synthetic or in watermelon, may improve vascular function through increased L-arginine bioavailability and nitric oxide synthesis. This article analyses potential vascular benefits of L-citrulline and watermelon supplementation at rest and during exercise. RECENT FINDINGS: There is clear evidence that acute L-citrulline ingestion increases plasma L-arginine, the substrate for endothelial nitric oxide synthesis. However, the subsequent acute improvement in nitric oxide production and mediated vasodilation is inconsistent, which likely explains the inability of acute L-citrulline or watermelon to improve exercise tolerance...
October 5, 2016: Current Opinion in Clinical Nutrition and Metabolic Care
Martin J MacInnis, Martin J Gibala
Interval exercise typically involves repeated bouts of relatively intense exercise interspersed by short periods of recovery. A common classification scheme subdivides this method into high-intensity interval training (HIIT; 'near maximal' efforts) and sprint interval training (SIT; 'supramaximal' efforts). Both forms of interval training induce the classic physiological adaptations characteristic of moderate-intensity continuous training (MICT) such as increased aerobic capacity (VO2max ) and mitochondrial content...
October 17, 2016: Journal of Physiology
Jason C Siegler, Paul W M Marshall, David Bishop, Greg Shaw, Simon Green
A large proportion of empirical research and reviews investigating the ergogenic potential of sodium bicarbonate (NaHCO3) supplementation have focused predominately on performance outcomes and only speculate about underlying mechanisms responsible for any benefit. The aim of this review was to critically evaluate the influence of NaHCO3 supplementation on mechanisms associated with skeletal muscle fatigue as it translates directly to exercise performance. Mechanistic links between skeletal muscle fatigue, proton accumulation (or metabolic acidosis) and NaHCO3 supplementation have been identified to provide a more targeted, evidence-based approach to direct future research, as well as provide practitioners with a contemporary perspective on the potential applications and limitations of this supplement...
December 2016: Sports Medicine—Open
Clark K Ho, Ganesh Sriram, Katrina M Dipple
Mathematical modeling approaches have been commonly used in complex signaling pathway studies such as the insulin signal transduction pathway. Our expanded mathematical model of the insulin signal transduction pathway was previously shown to effectively predict glucose clearance rates using mRNA levels of key components of the pathway in a mouse model. In this study, we re-optimized and applied our expanded model to study insulin sensitivity in other species and tissues (human skeletal muscle) with altered protein activities of insulin signal transduction pathway components...
October 11, 2016: Molecular Genetics and Metabolism
Chris McGlory, Michaela C Devries, Stuart M Phillips
Exercise results in the rapid remodelling of skeletal muscle imparting a positive impact on human health. This process is underpinned by acute and chronic changes in both gene and protein synthesis. In this short review we provide a brief summary of our current understanding regarding how exercise influences these processes as well as the subsequent impact on muscle protein turnover and resultant shift in muscle phenotype. We explore concepts of ribosomal biogenesis and the potential role of increased translational capacity versus translational efficiency in contributing to muscular hypertrophy...
October 14, 2016: Journal of Applied Physiology
Meredith J Luttrell, John R Halliwill
In humans, histamine is a molecular transducer of physical activity responses, and antihistamines modify > 25% of the genes responding to exercise. Although the upstream signal that results in release of histamine within exercising skeletal muscle remains to be identified, it is likely a fundamental exercise response and not an allergic reaction.
October 12, 2016: Exercise and Sport Sciences Reviews
Aaron P Russell, Marita A Wallace, Ming Kalanon, Evelyn Zacharewicz, Paul A Della Gatta, Andrew Garnham, Séverine Lamon
AIM: The striated muscle activator of Rho signalling (STARS) is a muscle-specific actin-binding protein. The STARS signalling pathway is activated by resistance exercise and is anticipated to play a role in signal mechanotransduction. Animal studies have reported a negative regulation of STARS signalling with age, but such regulation has not been investigated in humans. METHODS: Ten young (18-30 years) and 10 older (60-75 years) subjects completed an acute bout of resistance exercise...
October 14, 2016: Acta Physiologica
Lykke Sylow, Maximilian Kleinert, Erik A Richter, Thomas E Jensen
Skeletal muscle extracts glucose from the blood to maintain demand for carbohydrates as an energy source during exercise. Such uptake involves complex molecular signalling processes that are distinct from those activated by insulin. Exercise-stimulated glucose uptake is preserved in insulin-resistant muscle, emphasizing exercise as a therapeutic cornerstone among patients with metabolic diseases such as diabetes mellitus. Exercise increases uptake of glucose by up to 50-fold through the simultaneous stimulation of three key steps: delivery, transport across the muscle membrane and intracellular flux through metabolic processes (glycolysis and glucose oxidation)...
October 14, 2016: Nature Reviews. Endocrinology
Xijun Liang, Lin Liu, Tingting Fu, Qian Zhou, Danxia Zhou, Liwei Xiao, Jing Liu, Yan Kong, Hui Xie, Fanchao Yi, Ling Lai, Rick B Vega, Daniel P Kelly, Steven R Smith, Zhenji Gan
Lactate dehydrogenase (LDH) catalyzes the interconversion of pyruvate and lactate, which are critical fuel metabolites of skeletal muscle particularly during exercise. However, the physiological relevance of LDH remains poorly understood. Here we show that Ldhb expression is induced by exercise in human muscle and negatively correlated with changes in intramuscular pH levels, a marker of lactate production, during isometric exercise. We found that the expression of Ldhb is regulated by exercise-induced peroxisome proliferator-activated receptor-g coactivator 1α (PGC-1α)...
October 13, 2016: Journal of Biological Chemistry
Joseph J Knapik, Francis G O'Connor
Exertional rhabdomyolysis (ER) is a medical condition whereby damage to skeletal muscle is induced by excessive physical activity in otherwise healthy individuals. The individual performs so much activity that he/ she presumably depletes local muscle energy stores and muscle cells are unable to maintain cellular integrity, resulting in cell damage and the release of cellular contents, with resultant secondary complications. In the military services, the incidence of ER appeared to increase in the period 2004 to 2015...
2016: Journal of Special Operations Medicine: a Peer Reviewed Journal for SOF Medical Professionals
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"