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Effects of intracellular acidification and varied temperature on force, stiffness and speed of shortening in frog muscle fibres.

Radzyukevich, T. and Edman, Paul LU (2004) In American Journal of Physiology: Cell Physiology 287(1). p.106-113
Abstract
This study aimed to establish whether the temperature-dependent effect of acidification on maximum force observed in mammalian muscles also applies to frog muscle. Measurements of force, stiffness, and unloaded velocity of shortening in intact single muscle fibers from the anterior tibialis muscle of Rana temporaria were performed between 0 and 22degreesC during fused tetani in H2CO3CO2-buffered Ringer solution with pH adjusted to 7.0 and 6.3, respectively. The force-to-stiffness ratio increased as a rectilinear function of temperature between 0 and 20degreesC at pH 7.0. Lowering the pH to 6.3 reduced the tetanic force by 13.5+/-1.2 and 11.5+/-1.4% at 2.8 and 20.5degreesC, respectively, with only a minor reduction in fiber stiffness. The... (More)
This study aimed to establish whether the temperature-dependent effect of acidification on maximum force observed in mammalian muscles also applies to frog muscle. Measurements of force, stiffness, and unloaded velocity of shortening in intact single muscle fibers from the anterior tibialis muscle of Rana temporaria were performed between 0 and 22degreesC during fused tetani in H2CO3CO2-buffered Ringer solution with pH adjusted to 7.0 and 6.3, respectively. The force-to-stiffness ratio increased as a rectilinear function of temperature between 0 and 20degreesC at pH 7.0. Lowering the pH to 6.3 reduced the tetanic force by 13.5+/-1.2 and 11.5+/-1.4% at 2.8 and 20.5degreesC, respectively, with only a minor reduction in fiber stiffness. The maximum speed of shortening was decreased by lowered pH by 12.9+/-1.5 and 7.8+/-1.1% at low and high temperature, respectively. Acidification increased the time to reach 70% of maximum force by 18.0% at similar to2degreesC; the same pH change performed at similar to20degreesC in the same fibers reduced the rise time by 24.1%. The same increase in the rate of rise of force at high temperature was also found at normal pH after the fibers were fatigued by frequent stimulation. It is concluded that, in frog muscle, the force-depressant effect of acidification does not vary significantly with temperature. By contrast, acidification affects the onset of activation in a manner that is critically dependent on temperature. (Less)
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author
organization
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Contribution to journal
publication status
published
subject
keywords
muscle contraction, pH
in
American Journal of Physiology: Cell Physiology
volume
287
issue
1
pages
106 - 113
publisher
American Physiological Society
external identifiers
  • wos:000221926100013
  • pmid:14998789
  • scopus:2942636170
ISSN
1522-1563
DOI
10.1152/ajpcell.00472.2003
language
English
LU publication?
yes
id
19d8698c-774e-415a-ab12-9233e50045b3 (old id 121565)
alternative location
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14998789&dopt=Abstract
date added to LUP
2007-07-19 08:43:30
date last changed
2017-01-01 06:39:47
@article{19d8698c-774e-415a-ab12-9233e50045b3,
  abstract     = {This study aimed to establish whether the temperature-dependent effect of acidification on maximum force observed in mammalian muscles also applies to frog muscle. Measurements of force, stiffness, and unloaded velocity of shortening in intact single muscle fibers from the anterior tibialis muscle of Rana temporaria were performed between 0 and 22degreesC during fused tetani in H2CO3CO2-buffered Ringer solution with pH adjusted to 7.0 and 6.3, respectively. The force-to-stiffness ratio increased as a rectilinear function of temperature between 0 and 20degreesC at pH 7.0. Lowering the pH to 6.3 reduced the tetanic force by 13.5+/-1.2 and 11.5+/-1.4% at 2.8 and 20.5degreesC, respectively, with only a minor reduction in fiber stiffness. The maximum speed of shortening was decreased by lowered pH by 12.9+/-1.5 and 7.8+/-1.1% at low and high temperature, respectively. Acidification increased the time to reach 70% of maximum force by 18.0% at similar to2degreesC; the same pH change performed at similar to20degreesC in the same fibers reduced the rise time by 24.1%. The same increase in the rate of rise of force at high temperature was also found at normal pH after the fibers were fatigued by frequent stimulation. It is concluded that, in frog muscle, the force-depressant effect of acidification does not vary significantly with temperature. By contrast, acidification affects the onset of activation in a manner that is critically dependent on temperature.},
  author       = {Radzyukevich, T. and Edman, Paul},
  issn         = {1522-1563},
  keyword      = {muscle contraction,pH},
  language     = {eng},
  number       = {1},
  pages        = {106--113},
  publisher    = {American Physiological Society},
  series       = {American Journal of Physiology: Cell Physiology},
  title        = {Effects of intracellular acidification and varied temperature on force, stiffness and speed of shortening in frog muscle fibres.},
  url          = {http://dx.doi.org/10.1152/ajpcell.00472.2003},
  volume       = {287},
  year         = {2004},
}