Fiber-type composition of hindlimb muscles in the turtle,Pseudemys (Trachemys) scripta elegans

1995 ◽  
Vol 225 (2) ◽  
pp. 193-211 ◽  
Author(s):  
Douglass H. Laidlaw ◽  
Robert J. Callister ◽  
Douglas G. Stuart
Keyword(s):  
Fiber Type ◽  
Trachemys Scripta ◽  
Trachemys Scripta Elegans ◽  
Fiber Type Composition ◽  
Hindlimb Muscles ◽  
Type Composition

Fiber type composition of four hindlimb muscles of adult Fisher 344 rats

1999 ◽  
Vol 111 (2) ◽  
pp. 117-123 ◽  
Author(s):  
Robert S. Staron ◽  
William J. Kraemer ◽  
Robert S. Hikida ◽  
Andy C. Fry ◽  
Jerry D. Murray ◽  
...  
Keyword(s):  
Fiber Type ◽  
Fiber Type Composition ◽  
Hindlimb Muscles ◽  
Type Composition

Acute antioxidant supplementation and skeletal muscle vascular conductance in aged rats: role of exercise and fiber type

2011 ◽  
Vol 300 (4) ◽  
pp. H1536-H1544 ◽  
Author(s):  
Daniel M. Hirai ◽  
Steven W. Copp ◽  
Peter J. Schwagerl ◽  
Mark D. Haub ◽  
David C. Poole ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fiber Type ◽  
Whole Body ◽  
Aged Rats ◽  
Antioxidant Treatment ◽  
Vascular Conductance ◽  
Fiber Type Composition ◽  
Hindlimb Muscles ◽  
Type Composition

Age-related increases in oxidative stress contribute to impaired skeletal muscle vascular control. However, recent evidence indicates that antioxidant treatment with tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl) attenuates flow-mediated vasodilation in isolated arterioles from the highly oxidative soleus muscle of aged rats. Whether antioxidant treatment with tempol evokes similar responses in vivo at rest and during exercise in senescent individuals and whether this effect varies based on muscle fiber type composition are unknown. We tested the hypothesis that redox modulation via acute systemic tempol administration decreases vascular conductance (VC) primarily in oxidative hindlimb locomotor muscles at rest and during submaximal whole body exercise (treadmill running at 20 m/min, 5% grade) in aged rats. Eighteen old (25–26 mo) male Fischer 344 x Brown Norway rats were assigned to either rest ( n = 8) or exercise ( n = 10) groups. Regional VC was determined via radiolabeled microspheres before and after intra-arterial administration of tempol (302 μmol/kg). Tempol decreased mean arterial pressure significantly by 9% at rest and 16% during exercise. At rest, similar VC in 26 out of 28 individual hindlimb muscles or muscle parts following tempol administration compared with control resulted in unchanged total hindlimb muscle VC (control: 0.18 ± 0.02; tempol: 0.17 ± 0.05 ml·min−1·100 g−1·mmHg−1; P > 0.05). During exercise, all individual hindlimb muscles or muscle parts irrespective of fiber type composition exhibited either an increase or no change in VC with tempol (i.e., ↑11 and ↔17 muscles or muscle parts), such that total hindlimb VC increased by 25% (control: 0.93 ± 0.04; tempol: 1.15 ± 0.09 ml·min−1·100 g−1·mmHg−1; P ≤ 0.05). These results demonstrate that acute systemic administration of the antioxidant tempol significantly impacts the control of regional vascular tone in vivo presumably via redox modulation and improves skeletal muscle vasodilation independently of fiber type composition during submaximal whole body exercise in aged rats.

Myostatin regulates fiber-type composition of skeletal muscle by regulating MEF2 and MyoD gene expression

2009 ◽  
Vol 296 (3) ◽  
pp. C525-C534 ◽  
Author(s):  
Alex Hennebry ◽  
Carole Berry ◽  
Victoria Siriett ◽  
Paul O'Callaghan ◽  
Linda Chau ◽  
...  
Keyword(s):  
Growth Factor ◽  
Target Genes ◽  
Fiber Type ◽  
Fiber Formation ◽  
Type I ◽  
Mobility Shift ◽  
Enhancer Activity ◽  
Fiber Type Composition ◽  
Nuclear Extracts ◽  
Type Composition

Myostatin (Mstn) is a secreted growth factor belonging to the tranforming growth factor (TGF)-β superfamily. Inactivation of murine Mstn by gene targeting, or natural mutation of bovine or human Mstn, induces the double muscling (DM) phenotype. In DM cattle, Mstn deficiency increases fast glycolytic (type IIB) fiber formation in the biceps femoris (BF) muscle. Using Mstn null (−/−) mice, we suggest a possible mechanism behind Mstn-mediated fiber-type diversity. Histological analysis revealed increased type IIB fibers with a concomitant decrease in type IIA and type I fibers in the Mstn−/−tibialis anterior and BF muscle. Functional electrical stimulation of Mstn−/−BF revealed increased fatigue susceptibility, supporting increased type IIB fiber content. Given the role of myocyte enhancer factor 2 (MEF2) in oxidative type I fiber formation, MEF2 levels in Mstn−/−tissue were quantified. Results revealed reduced MEF2C protein in Mstn−/−muscle and myoblast nuclear extracts. Reduced MEF2-DNA complex was also observed in electrophoretic mobility-shift assay using Mstn−/−nuclear extracts. Furthermore, reduced expression of MEF2 downstream target genes MLC1F and calcineurin were found in Mstn−/−muscle. Conversely, Mstn addition was sufficient to directly upregulate MLC promoter-enhancer activity in cultured myoblasts. Since high MyoD levels are seen in fast fibers, we analyzed MyoD levels in the muscle. In contrast to MEF2C, MyoD levels were increased in Mstn−/−muscle. Together, these results suggest that while Mstn positively regulates MEF2C levels, it negatively regulates MyoD expression in muscle. We propose that Mstn could regulate fiber-type composition by regulating the expression of MEF2C and MyoD during myogenesis.

Fast-to-slow shift of muscle fiber-type composition by dietary apple polyphenols in rats: Impact of the low-dose supplementation

2016 ◽  
Vol 88 (3) ◽  
pp. 489-499 ◽  
Author(s):  
Wataru Mizunoya ◽  
Shinpei Okamoto ◽  
Hideo Miyahara ◽  
Mariko Akahoshi ◽  
Takahiro Suzuki ◽  
...  
Keyword(s):  
Muscle Fiber ◽  
Low Dose ◽  
Fiber Type ◽  
Muscle Fiber Type ◽  
Fiber Type Composition ◽  
Type Composition ◽  
Muscle Fiber Type Composition

Relationship of Fiber Type Composition to Marbling and Tenderness of Bovine Muscle

1981 ◽  
Vol 46 (3) ◽  
pp. 708-710 ◽  
Author(s):  
C. R. CALKINS ◽  
T. R. DUTSON ◽  
G. C. SMITH ◽  
Z. L. CARPENTER ◽  
G. W. DAVIS
Keyword(s):  
Fiber Type ◽  
Bovine Muscle ◽  
Fiber Type Composition ◽  
Type Composition ◽  
Relationship Of

177 EFFECT OF SPRINT TRAINING FREQUENCY ON MUSCLE FIBER TYPE COMPOSITION

1993 ◽  
Vol 25 (Supplement) ◽  
pp. S33
Author(s):  
M. Esbj??rnsson ◽  
Y. H-Westing ◽  
P. Balsom ◽  
B. Sj??din ◽  
E. Jansson
Keyword(s):  
Muscle Fiber ◽  
Fiber Type ◽  
Muscle Fiber Type ◽  
Sprint Training ◽  
Fiber Type Composition ◽  
Type Composition ◽  
Training Frequency ◽  
Muscle Fiber Type Composition
Sign in / Sign up

Export Citation Format

Share Document