scholarly journals Semi-automated Analysis of Mouse Skeletal Muscle Morphology and Fiber-type Composition

10.3791/56024 ◽  
2017 ◽  
Author(s):  
Sidharth Tyagi ◽  
Donald Beqollari ◽  
Chang Seok Lee ◽  
Lori A. Walker ◽  
Roger A. Bannister
Keyword(s):  
Skeletal Muscle ◽  
Fiber Type ◽  
Automated Analysis ◽  
Muscle Morphology ◽  
Mouse Skeletal Muscle ◽  
Fiber Type Composition ◽  
Type Composition

Gene Polymorphisms and Fiber-Type Composition of Human Skeletal Muscle

2012 ◽  
Vol 22 (4) ◽  
pp. 292-303 ◽  
Author(s):  
Ildus I. Ahmetov ◽  
Olga L. Vinogradova ◽  
Alun G. Williams
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fiber ◽  
Human Skeletal Muscle ◽  
Fiber Type ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Fiber Types ◽  
Fiber Type Composition ◽  
Type Composition ◽  
Type I Fibers

The ability to perform aerobic or anaerobic exercise varies widely among individuals, partially depending on their muscle-fiber composition. Variability in the proportion of skeletal-muscle fiber types may also explain marked differences in aspects of certain chronic disease states including obesity, insulin resistance, and hypertension. In untrained individuals, the proportion of slow-twitch (Type I) fibers in the vastus lateralis muscle is typically around 50% (range 5–90%), and it is unusual for them to undergo conversion to fast-twitch fibers. It has been suggested that the genetic component for the observed variability in the proportion of Type I fibers in human muscles is on the order of 40–50%, indicating that muscle fiber-type composition is determined by both genotype and environment. This article briefly reviews current progress in the understanding of genetic determinism of fiber-type proportion in human skeletal muscle. Several polymorphisms of genes involved in the calcineurin–NFAT pathway, mitochondrial biogenesis, glucose and lipid metabolism, cytoskeletal function, hypoxia and angiogenesis, and circulatory homeostasis have been associated with fiber-type composition. As muscle is a major contributor to metabolism and physical strength and can readily adapt, it is not surprising that many of these gene variants have been associated with physical performance and athlete status, as well as metabolic and cardiovascular diseases. Genetic variants associated with fiber-type proportions have important implications for our understanding of muscle function in both health and disease.

scholarly journals Acetylcholine and insulin‐mediated vasodilation in feed arteries and arterioles of rat skeletal muscle of different fiber type composition

2012 ◽  
Vol 26 (S1) ◽  
Author(s):  
Jaume Padilla ◽  
Nathan T Jenkins ◽  
Jeffrey S Martin ◽  
Jacqueline M Crissey ◽  
Shawn B Bender ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fiber Type ◽  
Rat Skeletal Muscle ◽  
Fiber Type Composition ◽  
Type Composition ◽  
Feed Arteries

scholarly journals Treadmill Slope Modulates Inflammation, Fiber Type Composition, Androgen, and Glucocorticoid Receptors in the Skeletal Muscle of Overtrained Mice

2017 ◽  
Vol 8 ◽  
Author(s):  
Alisson L. da Rocha ◽  
Bruno C. Pereira ◽  
Giovana R. Teixeira ◽  
Ana P. Pinto ◽  
Fabiani G. Frantz ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Glucocorticoid Receptors ◽  
Fiber Type ◽  
Fiber Type Composition ◽  
Type Composition

Nature vs. nurture: can exercise really alter fiber type composition in human skeletal muscle?

2004 ◽  
Vol 97 (5) ◽  
pp. 1591-1592 ◽  
Author(s):  
Christopher P. Ingalls
Keyword(s):  
Skeletal Muscle ◽  
Enzyme Activity ◽  
Human Skeletal Muscle ◽  
Fiber Type ◽  
Historical Significance ◽  
Fiber Type Composition ◽  
Fiber Composition ◽  
Type Composition ◽  
Nature Vs Nurture ◽  
Classic Papers

This essay looks at the historical significance of two APS classic papers that are freely available online: Gollnick PD, Armstrong RB, Saubert CW IV, Piehl K, and Saltin B. Enzyme activity and fiber composition in skeletal muscle of untrained and trained men. J Appl Physiol 33: 312—319, 1972 ( http://jap.physiology.org/cgi/reprint/33/3/312 ). Gollnick PD, Armstrong RB, Saltin B, Saubert CW IV, Sembrowich WL, and Shepherd RE. Effect of training on enzyme activity and fiber composition of human skeletal muscle. J Appl Physiol 34: 107—111, 1973 ( http://jap.physiology.org/cgi/reprint/34/1/107 ).

The regulation of skeletal muscle fiber-type composition by betaine is associated with NFATc1/MyoD

2018 ◽  
Vol 96 (7) ◽  
pp. 685-700 ◽  
Author(s):  
Jingjing Du ◽  
Linyuan Shen ◽  
Peiwen Zhang ◽  
Zhendong Tan ◽  
Xiao Cheng ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fiber ◽  
Fiber Type ◽  
Skeletal Muscle Fiber ◽  
Muscle Fiber Type ◽  
Fiber Type Composition ◽  
Type Composition ◽  
Muscle Fiber Type Composition

Strength, power, fiber types, and mRNA expression in trained men and women with different ACTN3 R577X genotypes

2009 ◽  
Vol 106 (3) ◽  
pp. 959-965 ◽  
Author(s):  
Barbara Norman ◽  
Mona Esbjörnsson ◽  
Håkan Rundqvist ◽  
Ted Österlund ◽  
Ferdinand von Walden ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fiber ◽  
Fiber Type ◽  
Muscle Fiber Types ◽  
Vastus Lateralis Muscle ◽  
Fiber Types ◽  
Mrna Levels ◽  
Men And Women ◽  
Fiber Type Composition ◽  
Type Composition

α-Actinins are structural proteins of the Z-line. Human skeletal muscle expresses two α-actinin isoforms, α-actinin-2 and α-actinin-3, encoded by their respective genes ACTN2 and ACTN3. ACTN2 is expressed in all muscle fiber types, while only type II fibers, and particularly the type IIb fibers, express ACTN3. ACTN3 (R577X) polymorphism results in loss of α-actinin-3 and has been suggested to influence skeletal muscle function. The X allele is less common in elite sprint and power athletes than in the general population and has been suggested to be detrimental for performance requiring high power. The present study investigated the association of ACTN3 genotype with muscle power during 30-s Wingate cycling in 120 moderately to well-trained men and women and with knee extensor strength and fatigability in a subset of 21 men performing isokinetic exercise. Muscle biopsies were obtained from the vastus lateralis muscle to determine fiber-type composition and ACTN2 and ACTN3 mRNA levels. Peak and mean power and the torque-velocity relationship and fatigability output showed no difference across ACTN3 genotypes. Thus this study suggests that R577X polymorphism in ACTN3 is not associated with differences in power output, fatigability, or force-velocity characteristics in moderately trained individuals. However, repeated exercise bouts prompted an increase in peak torque in RR but not in XX genotypes, suggesting that ACTN3 genotype may modulate responsiveness to training. Our data further suggest that α-actinins do not play a significant role in determining muscle fiber-type composition. Finally, we show that ACTN2 expression is affected by the content of α-actinin-3, which implies that α-actinin-2 may compensate for the lack of α-actinin-3 and hence counteract the phenotypic consequences of the deficiency.

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