Variability in Microvascular Pattern Dependent upon Muscle Fiber Composition

2015 ◽  
pp. 15-29 ◽  
Author(s):  
H. -J. Appell
Keyword(s):  
Muscle Fiber ◽  
Fiber Composition ◽  
Microvascular Pattern

Effect of heavy-resistance exercise training on muscle fiber composition in young rats

1990 ◽  
Vol 69 (2) ◽  
pp. 434-437 ◽  
Author(s):  
K. E. Yarasheski ◽  
P. W. Lemon ◽  
J. Gilloteaux
Keyword(s):  
Exercise Training ◽  
Resistance Exercise ◽  
Muscle Fiber ◽  
Rectus Femoris ◽  
Type I ◽  
Resistance Exercise Training ◽  
Fiber Composition ◽  
Deep Region ◽  
Heavy Resistance Exercise ◽  
Type I Fibers

The purpose of this investigation was to determine whether heavy-resistance exercise training alters the skeletal muscle fiber composition of young rats. Ten male Long Evans rats (3 wk old) were trained to lift progressively heavier weights, which were secured to the rats' tails, while they ascended a 40-cm 90 degree mesh incline 20 times/day 5 days/wk for a food reward. After 8 wk of training, they lifted 406 +/- 19 (SD) g in addition to their body weight (261 +/- 9 g). Compared with 10 sedentary pair-fed rats, no hypertrophy of forelimb muscles (biceps brachii and brachialis) was observed, but rectus femoris wet and dry weights were greater (P less than 0.01) in the trained group. In the deep region of the rectus femoris, type I fiber area was similar between groups, but the trained rats had both a lower (P less than 0.05) percentage of type I fibers and a smaller (P less than 0.05) portion of the total area occupied by type I fibers. The percentage of type IIb fibers in the deep region of the rectus femoris was also similar between groups, but the portion of the deep area composed of type IIb fibers was greater (P less than 0.05) in the trained rats. In the superficial region of the rectus femoris, the trained rats' type IIb fibers were larger (P less than 0.01) and occupied a greater (P less than 0.05) portion of the superficial muscle area.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals PPARGC1A rs8192678 and NRF1 rs6949152 Polymorphisms Are Associated with Muscle Fiber Composition in Women

Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1012
Author(s):  
Thomas Yvert ◽  
Eri Miyamoto-Mikami ◽  
Takuro Tobina ◽  
Keisuke Shiose ◽  
Ryo Kakigi ◽  
...  
Keyword(s):  
Muscle Fiber ◽  
Vastus Lateralis ◽  
Endurance Performance ◽  
Individual Variability ◽  
Lower Proportion ◽  
Vastus Lateralis Muscle ◽  
Mhc I ◽  
Fiber Composition ◽  
Individual Variations ◽  
Health Related

PPARGC1A rs8192678 G/A (Gly482Ser) and NRF1 rs6949152 A/G polymorphisms have been associated with endurance athlete status, endurance performance phenotypes, and certain health-related markers of different pathologies such as metabolic syndrome, diabetes, and dyslipidemia. We hypothesized that they could be considered interesting candidates for explaining inter-individual variations in muscle fiber composition in humans. We aimed to examine possible associations of these polymorphisms with myosin heavy-chain (MHC) isoforms as markers of muscle fiber compositions in vastus lateralis muscle in a population of 214 healthy Japanese subjects, aged between 19 and 79 years. No significant associations were found in men for any measured variables. In contrast, in women, the PPARGC1A rs8192678 A/A genotype was significantly associated with a higher proportion of MHC-I (p = 0.042) and with a lower proportion of MHC-IIx (p = 0.033), and the NRF1 rs6949152 AA genotype was significantly associated with a higher proportion of MHC-I (p = 0.008) and with a lower proportion of MHC IIx (p = 0.035). In women, the genotype scores of the modes presenting the most significant results for PPARGC1A rs8192678 G/A (Gly482Ser) and NRF1 rs6949152 A/G polymorphisms were significantly associated with MHC-I (p = 0.0007) and MHC IIx (p = 0.0016). That is, women with combined PPARGC1A A/A and NRF1 A/A genotypes presented the highest proportion of MHC-I and the lowest proportion of MHC-IIx, in contrast to women with combined PPARGC1A GG+GA and NRF1 AG+GG genotypes, who presented the lowest proportion of MHC-I and the highest proportion of MHC-IIx. Our results suggest possible associations between these polymorphisms (both individually and in combination) and the inter-individual variability observed in muscle fiber composition in women, but not in men.

Genetics of muscle fiber composition

2019 ◽  
pp. 295-314 ◽  
Author(s):  
Noriyuki Fuku ◽  
Hiroshi Kumagai ◽  
Ildus I. Ahmetov
Keyword(s):  
Muscle Fiber ◽  
Fiber Composition

The sternomastoid muscle of the rat and its innervation. Muscle fiber composition, perikarya and axons of efferent and afferent neurons

1980 ◽  
Vol 160 (3) ◽  
pp. 285-300 ◽  
Author(s):  
J. Gottschall ◽  
W. Zenker ◽  
W. Neuhuber ◽  
A. Mysicka ◽  
M. M�ntener
Keyword(s):  
Muscle Fiber ◽  
Afferent Neurons ◽  
Sternomastoid Muscle ◽  
Fiber Composition

Influence Of Muscle Fiber Composition On Oxygen Uptake Kinetics

2007 ◽  
Vol 39 (Supplement) ◽  
pp. S359
Author(s):  
Alessandra Ferri ◽  
Greig Watson ◽  
Paul Laursen ◽  
Bruno Grassi ◽  
Giuseppe Miserocchi ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Muscle Fiber ◽  
Oxygen Uptake Kinetics ◽  
Uptake Kinetics ◽  
Fiber Composition

Muscle Fiber Composition and Enzyme Activities in Elite Female Distance Runners*

1987 ◽  
Vol 08 (S 2) ◽  
pp. S103-S106 ◽  
Author(s):  
D. Costill ◽  
W. Fink ◽  
M. Flynn ◽  
J. Kirwan
Keyword(s):  
Muscle Fiber ◽  
Enzyme Activities ◽  
Distance Runners ◽  
Fiber Composition
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