Effects of phosphate on the contractile properties of fast and slow muscle fibres from an Antarctic fish.
Single fast myotomal fibres and small bundles of slow fibres (from the adductor pectoralis profundus muscle) were isolated from the Antarctic teleost Notothenia neglecta. Fibres were skinned by a brief detergent treatment. The effects of phosphate on the mechanical properties and ATPase activity of...
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Language: | English |
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crwiley:10.1113/jphysiol.1985.sp015871 2024-09-09T19:11:07+00:00 Effects of phosphate on the contractile properties of fast and slow muscle fibres from an Antarctic fish. Altringham, J D Johnston, I A 1985 http://dx.doi.org/10.1113/jphysiol.1985.sp015871 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1113%2Fjphysiol.1985.sp015871 https://physoc.onlinelibrary.wiley.com/doi/pdf/10.1113/jphysiol.1985.sp015871 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor The Journal of Physiology volume 368, issue 1, page 491-500 ISSN 0022-3751 1469-7793 journal-article 1985 crwiley https://doi.org/10.1113/jphysiol.1985.sp015871 2024-06-20T04:25:50Z Single fast myotomal fibres and small bundles of slow fibres (from the adductor pectoralis profundus muscle) were isolated from the Antarctic teleost Notothenia neglecta. Fibres were skinned by a brief detergent treatment. The effects of phosphate on the mechanical properties and ATPase activity of fast and slow fibres were studied. 20 mM‐phosphate inhibited maximum isometric tension in slow fibres by 34%, but by only 11% in fast fibres. A half‐maximal response was obtained at approximately 5 mM‐phosphate. These concentrations are within the range measured in muscle, and the effect is probably of physiological significance. This species is of particular interest, since there is evidence that the energy supply to the fast muscle is largely based on phosphocreatine breakdown, which would result in large changes in intracellular phosphate concentration during exercise. The maximum contraction velocity of both fast and slow fibres was not affected by 10 mM‐phosphate, nor was the ATPase activity of the slow fibres during isometric contraction. The phosphate‐induced depression in tension in slow fibres was associated with a proportional decrease in stiffness. The rate of force recovery after rapid, small amplitude stretches and releases was increased by phosphate, as was the rate of rise of force during stretch activation. The results are discussed with reference to the different patterns of energy supply for contraction in muscle, and an attempt is made at explaining the data in terms of changes in cross‐bridge kinetics. Article in Journal/Newspaper Antarc* Antarctic Wiley Online Library Antarctic The Antarctic The Journal of Physiology 368 1 491 500 |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Single fast myotomal fibres and small bundles of slow fibres (from the adductor pectoralis profundus muscle) were isolated from the Antarctic teleost Notothenia neglecta. Fibres were skinned by a brief detergent treatment. The effects of phosphate on the mechanical properties and ATPase activity of fast and slow fibres were studied. 20 mM‐phosphate inhibited maximum isometric tension in slow fibres by 34%, but by only 11% in fast fibres. A half‐maximal response was obtained at approximately 5 mM‐phosphate. These concentrations are within the range measured in muscle, and the effect is probably of physiological significance. This species is of particular interest, since there is evidence that the energy supply to the fast muscle is largely based on phosphocreatine breakdown, which would result in large changes in intracellular phosphate concentration during exercise. The maximum contraction velocity of both fast and slow fibres was not affected by 10 mM‐phosphate, nor was the ATPase activity of the slow fibres during isometric contraction. The phosphate‐induced depression in tension in slow fibres was associated with a proportional decrease in stiffness. The rate of force recovery after rapid, small amplitude stretches and releases was increased by phosphate, as was the rate of rise of force during stretch activation. The results are discussed with reference to the different patterns of energy supply for contraction in muscle, and an attempt is made at explaining the data in terms of changes in cross‐bridge kinetics. |
format |
Article in Journal/Newspaper |
author |
Altringham, J D Johnston, I A |
spellingShingle |
Altringham, J D Johnston, I A Effects of phosphate on the contractile properties of fast and slow muscle fibres from an Antarctic fish. |
author_facet |
Altringham, J D Johnston, I A |
author_sort |
Altringham, J D |
title |
Effects of phosphate on the contractile properties of fast and slow muscle fibres from an Antarctic fish. |
title_short |
Effects of phosphate on the contractile properties of fast and slow muscle fibres from an Antarctic fish. |
title_full |
Effects of phosphate on the contractile properties of fast and slow muscle fibres from an Antarctic fish. |
title_fullStr |
Effects of phosphate on the contractile properties of fast and slow muscle fibres from an Antarctic fish. |
title_full_unstemmed |
Effects of phosphate on the contractile properties of fast and slow muscle fibres from an Antarctic fish. |
title_sort |
effects of phosphate on the contractile properties of fast and slow muscle fibres from an antarctic fish. |
publisher |
Wiley |
publishDate |
1985 |
url |
http://dx.doi.org/10.1113/jphysiol.1985.sp015871 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1113%2Fjphysiol.1985.sp015871 https://physoc.onlinelibrary.wiley.com/doi/pdf/10.1113/jphysiol.1985.sp015871 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
The Journal of Physiology volume 368, issue 1, page 491-500 ISSN 0022-3751 1469-7793 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1113/jphysiol.1985.sp015871 |
container_title |
The Journal of Physiology |
container_volume |
368 |
container_issue |
1 |
container_start_page |
491 |
op_container_end_page |
500 |
_version_ |
1809826770457722880 |