|
| |
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
Journal of Experimental Biology, Vol 185, Issue 1 195-206, Copyright © 1993 by Company of Biologists
JOURNAL ARTICLES |
N. A. Curtin and R. C. Woledge
Bundles of red myotomal muscle fibres isolated from dogfish were electrically stimulated at 12 sC. Peak twitch force was 54 % of that produced by a brief isometric tetanus. Relaxation was slower than in white fibres, but much faster than would be expected for the tonic fibres found in amphibian muscle. These two results indicate that the red fibres in dogfish are slow, but not tonic, in their behaviour. Net work output and heat production were measured during complete cycles of sinusoidal movement. The following variables were kept constant: peak-to-peak movement, about 7 % of the muscle fibre length; tetanus duration, 33 % of the mechanical cycle time; stimulus frequency, 40 Hz. The frequency of movement and the timing of the stimulation were varied for each preparation to find the conditions optimal for power output and those optimal for efficiency (the ratio of net work output to total energy output as heat+work). To achieve either maximum power or maximum efficiency, the tetanus must start while the muscle fibres are being stretched, before the beginning of the shortening part of the mechanical cycle. The highest power output was produced during movement at 1.02 Hz. The highest efficiency, 0.507+/-0.045 (+/-s.e.m., N=9), was at 0.61-0.95 Hz. The efficiency is higher than that previously measured during sinusoidal movement of white fibres; the difference, 0.095+/- 0.045 (+/-s.e.m. of the difference, d.f. 20), is statistically significant at the 5 % level.
This article has been cited by other articles:
|
|
 |
|
  M. Trinh and D. A. Syme Effects of stretch on work and efficiency of frog (Rana pipiens) muscle J. Exp. Biol., August 15, 2007; 210(16): 2843 - 2850. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. M. Donley, R. E. Shadwick, C. A. Sepulveda, and D. A. Syme Thermal dependence of contractile properties of the aerobic locomotor muscle in the leopard shark and shortfin mako shark J. Exp. Biol., April 1, 2007; 210(7): 1194 - 1203. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. van Ginneken, E. Antonissen, U. K. Muller, R. Booms, E. Eding, J. Verreth, and G. van den Thillart Eel migration to the Sargasso: remarkably high swimming efficiency and low energy costs J. Exp. Biol., April 1, 2005; 208(7): 1329 - 1335. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. R. Watson, T. A. Miller, and R. W. Davis Immunohistochemical fiber typing of harbor seal skeletal muscle J. Exp. Biol., November 15, 2003; 206(22): 4105 - 4111. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Swimming speed estimation of extinct marine reptiles: energetic approach revisited Paleobiology, June 1, 2002; 28(2): 251 - 262.
|
|
|
|
|
|
F. Lou, N. A. Curtin, and R. C. Woledge Isometric and isovelocity contractile performance of red musle fibres from the dogfish Scyliorhinus canicula J. Exp. Biol., June 1, 2002; 205(11): 1585 - 1595. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Abbate, C. J. De Ruiter, C. Offringa, A. J. Sargeant, and A. De Haan In situ rat fast skeletal muscle is more efficient at submaximal than at maximal activation levels J Appl Physiol, May 1, 2002; 92(5): 2089 - 2096. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Ellerby, I. Spierts, and J. Altringham Slow muscle power output of yellow- and silver-phase European eels (Anguilla anguilla L.): changes in muscle performance prior to migration J. Exp. Biol., January 4, 2001; 204(7): 1369 - 1379. [Abstract] [PDF]
|
|
|
|
|
|
N. Curtin, R. Woledge, and Q Bone Energy storage by passive elastic structures in the mantle of sepia officinalis J. Exp. Biol., January 3, 2000; 203(5): 869 - 878. [Abstract] [PDF]
|
|
