scholarly journals Myosin heavy chain isoform profiles remain altered at 7 months if the lacerated medial gastrocnemius is poorly reinnervated: A study in rabbits

2009 ◽  
Vol 28 (6) ◽  
pp. 732-738 ◽  
Author(s):  
Barry P. Pereira ◽  
Hwan Chour Han ◽  
Zou Yu ◽  
Bee-Leng Tan ◽  
Zheng Ling ◽  
...  
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Medial Gastrocnemius ◽  
Myosin Heavy Chain Isoform

Adaptations in physiological properties of rat motor units following 5 weeks of whole-body vibration

2013 ◽  
Vol 38 (9) ◽  
pp. 913-921 ◽  
Author(s):  
Dawid Łochyński ◽  
Marcin Bączyk ◽  
Dominik Kaczmarek ◽  
Maria Jolanta Rędowicz ◽  
Jan Celichowski ◽  
...  
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Whole Body Vibration ◽  
Motor Units ◽  
Medial Gastrocnemius ◽  
Whole Body ◽  
Force Frequency ◽  
Body Vibration ◽  
Myosin Heavy Chain Isoform ◽  
Twitch Contraction

The purpose of the study was to determine the effects of 5-week whole-body vibration (WBV) on contractile parameters and force–frequency relationship of functionally isolated motor units of the rat medial gastrocnemius muscle: fast fatigable (FF), fast fatigue-resistant (FR), and slow (S). Moreover, myosin heavy chain isoform content was quantified. Following WBV, the maximum tetanic force of FF units was increased by ∼25%. The twitch half-relaxation time in all types of motor units and the twitch contraction time in FR units were shortened. The twitch-to-tetanus force ratio was decreased and the force–frequency curves were shifted rightwards in S and FR units. Myosin heavy chain distribution was not changed. These findings suggest modifications of the excitation–contraction coupling towards shortening of a twitch contraction. The observed increase in force of FF units may contribute to gains in muscle dynamic strength reported following WBV treatment.

scholarly journals The Drosophila indirect flight muscle myosin heavy chain isoform is insufficient to transform the jump muscle into a highly stretch-activated muscle type

2017 ◽  
Vol 312 (2) ◽  
pp. C111-C118 ◽  
Author(s):  
Cuiping Zhao ◽  
Douglas M. Swank
Keyword(s):  
Power Generation ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Flight Muscle ◽  
Fold Increase ◽  
Isometric Tension ◽  
Indirect Flight Muscle ◽  
Muscle Type ◽  
Myosin Heavy Chain Isoform ◽  
Muscle Types

Stretch activation (SA) is a delayed increase in force that enables high power and efficiency from a cyclically contracting muscle. SA exists in various degrees in almost all muscle types. In Drosophila, the indirect flight muscle (IFM) displays exceptionally high SA force production ( FSA), whereas the jump muscle produces only minimal FSA. We previously found that expressing an embryonic (EMB) myosin heavy chain (MHC) isoform in the jump muscle transforms it into a moderately SA muscle type and enables positive cyclical power generation. To investigate whether variation in MHC isoforms is sufficient to produce even higher FSA, we substituted the IFM MHC isoform (IFI) into the jump muscle. Surprisingly, we found that IFI only caused a 1.7-fold increase in FSA, less than half the increase previously observed with EMB, and only at a high Pi concentration, 16 mM. This IFI-induced FSA is much less than what occurs in IFM, relative to isometric tension, and did not enable positive cyclical power generation by the jump muscle. Both isometric tension and FSA of control fibers decreased with increasing Pi concentration. However, for IFI-expressing fibers, only isometric tension decreased. The rate of FSA generation was ~1.5-fold faster for IFI fibers than control fibers, and both rates were Pi dependent. We conclude that MHC isoforms can alter FSA and hence cyclical power generation but that isoforms can only endow a muscle type with moderate FSA. Highly SA muscle types, such as IFM, likely use a different or additional mechanism.

Effect of Dietary Creatine on Skeletal Muscle Myosin Heavy Chain Isoform Expression in an Animal Model of Uremia

2004 ◽  
Vol 96 (4) ◽  
pp. e103-e110 ◽  
Author(s):  
Youri E.C. Taes ◽  
Marijn Speeckaert ◽  
Evelien Bauwens ◽  
Marc R. De Buyzere ◽  
Johan Libbrecht ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Animal Model ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Skeletal Muscle Myosin ◽  
Myosin Heavy Chain Isoform ◽  
Isoform Expression ◽  
Muscle Myosin

Myosin heavy chain isoform composition in the deltoid and vastus lateralis muscles of elite handball players

2020 ◽  
Vol 38 (20) ◽  
pp. 2390-2395
Author(s):  
Athanasios Mandroukas ◽  
Thomas I. Metaxas ◽  
Zacharoula Papadopoulou ◽  
Jan Heller ◽  
Nikos V. Margaritelis ◽  
...  
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Vastus Lateralis ◽  
Myosin Heavy Chain Isoform
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