Journal ArticleDOI
The proliferation of myofibrils during muscle fibre growth.
TLDR
From data on the size, shape and number of myofibrils at different stages of growth it was concluded that longitudinal splitting is the means by which the number ofMyofibril increases during post-natal growth.Abstract:
Myofibrils in muscle fibres of different sizes and different ages were examined and measured using phase-contrast and electron microscopy. During the post-natal growth of the mouse biceps brachii muscle the number of myofibrils in some fibres increases from about 75 to 1200 The range of myofibril size was from 0.4-1.2 µm. The distribution of myofibril sizes in muscles of all ages studied was bimodal A high incidence of longitudinal splitting of myofibrils was observed with the electron microscope in differentiating muscle fibres and in some medium and large muscle fibres. Size measurements with the electron microscope showed that the splitting myofibrils were about twice as large as non-splitting myofibrils and that the myofibrils split more or less down the middle. A possible explanation for the splitting is that the peripheral I filaments are pulled at an angle slightly oblique to the myofibril axis, because of the discrepancy in the A and I-filament lattice spacings. When the myofibril reaches a certain size the oblique pull of the peripheral I filaments is strong enough to cause the Z disks to rip. From data on the size, shape and number of myofibrils at different stages of growth it was concluded that longitudinal splitting is the means by which the number of myofibrils increases during post-natal growth.read more
Citations
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Journal ArticleDOI
The adaptations to strength training : morphological and neurological contributions to increased strength.
TL;DR: The gains in strength with HRST are undoubtedly due to a wide combination of neurological and morphological factors, although there is contrary evidence suggesting no change in cortical or corticospinal excitability.
OtherDOI
Skeletal Muscle Adaptability: Significance for Metabolism and Performance
Bengt Saltin,Philip D. Gollnick +1 more
TL;DR: The sections in this article are:============\/\/\/\/\/\/£££1.11\/\/£2.10\/\/£3\/\/£4\/\/£5\/\/£6.1\/\/£7.2\/\/£8\/\/£9\/\/£10\/\/ £1.7\/\/£11.5\/\/ £2.9\/\/ £3£3£4£4 £6.2£5.3£7\/\/ £7.4£8£9.5£10.2 £7======
Journal ArticleDOI
Skeletal muscle adaptations during early phase of heavy-resistance training in men and women
Robert S. Staron,D. L. Karapondo,William J. Kraemer,Andrew C. Fry,Scott E. Gordon,J. E. Falkel,Fredrick C. Hagerman,Robert S. Hikida +7 more
TL;DR: The data suggest that skeletal muscle adaptations that may contribute to strength gains of the lower extremity are similar for men and women during the early phase of resistance training and, with the exception of changes in the fast fiber type composition, that they occur gradually.
Journal ArticleDOI
Skeletal-muscle growth and protein turnover.
TL;DR: It is suggested that increased rates of protein breakdown are a necessary accompaniment to muscle growth and may result from the way in which myofibrils proliferate.
Journal ArticleDOI
Desmin and vimentin coexist at the periphery of the myofibril Z disc
Bruce L. Granger,Elias Lazarides +1 more
TL;DR: Two-dimensional gel electrophoresis has revealed that vimentin, the predominant subunit of intermediate filaments in cells of mesenchymal origin, is a component of isolated skeletal myofibrils and may be involved in maintaining the lateral registration of sarcomeres by transversely linking adjacent my ofibrils at their Z discs.
References
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Journal ArticleDOI
The double array of filaments in cross-striated muscle.
TL;DR: The arrangement of the filaments and the changes associated with contraction and with stretch are identical to those already deduced from previous observations and described in terms of the interdigitating filament model in previous papers, so there are excellent grounds for believing that this model is correct.
Journal ArticleDOI
An electron microscope study of myofibril formation in embryonic chick skeletal muscle
TL;DR: An hypothesis concerning myofibril growth, based on the self-assembly characteristics of the filaments, is presented.
Journal ArticleDOI
The ultrastructure of the z disc in skeletal muscle
G. G. Knappeis,F. Carlsen +1 more
TL;DR: This structural arrangement is interpreted to indicate that each I filament on one side of the Z disc faces the center of the space between four I filaments on the opposite side of Z and that the interconnection is formed by four Z filaments.
Muscle fibre growth in five different muscles in both sexes of mice. I. Normal mice.
R W Rowe,G Goldspink +1 more
Journal Article
Muscle fibre growth in five different muscles in both sexes of mice.
R W Rowe,G Goldspink +1 more
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