Abstract
Experiments were carried out to compare the stiffness of cross-bridges in amphibian slow and twitch muscle. an isolated iliofibularis muscle was subjected to rapid, small stretches during contraction of either slow or twitch fibres at a number of different isometric tensions. The method of analysis allowed the compliance of the cross-bridges to be distinguished from other sources of compliance. Provided that the muscle was stretched sufficiently rapidly to obtain limiting values of stiffness, little difference was found between the mechanical properties of the cross-bridges in slow and twitch muscle. It is concluded that the difference in observed stiffness of the two muscle types is due to a lower turnover rate of cross-bridges and a smaller number of sarcomeres in slow fibres.
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Brown, M. C.: The response of frog muscle spindles and fast and slow muscle fibres to a variety of mechanical inputs. J. Physiol. (Lond.)218, 1–17 (1971)
Chambers, R. M., Simcock, J. P.: Postural reflexes in forelimb of toad. J. Neurophysiol.23, 54–61 (1960)
Constantin, L. L., Podolsky, R. J., Tice, L. W.: Calcium activation of frog slow muscle fibres. J. Physiol. (Lond.)188, 261–271 (1967)
Coupland, R. E., Holmes, R. L.: The use of cholinesterase techniques for the demonstration of peripheral nervous structures. Quart. J. Micr. Sci.98, 327–330 (1957)
Flitney, F. W., Hirst, D. G.: Short-range elastic properties of contracting frog's muscle. J. Physiol. (Lond.)239, 119–121P (1974)
Flitney, F. W., Hirst, D. G.: Tension responses and sarcomere movements during length changes applied to contracting frog's muscle. J. Physiol. (Lond.)251, 66–68P (1975)
Ford, L. E., Huxley, A. F., Simmons, R. M.: The instantaneous elasticity of frog skeletal muscle fibres. J. Physiol. (Lond.)260, 28–29P (1976)
Huxley, A. F.: Muscular contraction. J. Physiol. (Lond.)243, 1–43 (1974)
Huxley, A. F., Simmons, R. M.: Proposed mechanism of force generation in striated muscle. Nature233, 533–538 (1971)
Kuffler, S. W., Vaughan-Williams, E. M.: Small nerve junction potentials. The distribution of small motor nerves to frog skeletal muscle, and the membrane characteristics of the fibres they innervate. J. Physiol. (Lond.)121, 289–317 (1953a)
Kuffler, S. W., Vaughan-Williams, E. M.: Properties of the “slow” skeletal muscle fibres of the frog. J. Physiol. (Lond.)121, 318–340 (1953b)
Morgan, D. L.: Separation of active and passive components of short-range stiffness of muscle. Am. J. Physiol.232, 45–49 (1977)
Proske, U., Rack, P. M. H.: Short-range stiffness of slow fibres and twitch fibres in reptilian muscle. Am. J. Physiol.231, 449–453 (1976)
Rack, P. M. H., Westbury, D. R.: The short range stiffness of active mammalian muscle and its effect on mechanical properties. J. Physiol. (Lond.)240, 331–350 (1974)
Sandow, A.: Diffraction patterns of the frog sartorius and sarcomere behaviour under stretch. J. Cell Comp. Physiol.9, 37–54 (1936)
Smith, R. S., Blinston, G., Ovalle, W. K.: Skeletomotor and fusimotor organization in amphibians. In: Control of Posture and Locomotion. Advances in Behavioural Biology, vol. 7 (R. B. Stein, K. G. Pearson, R. S. Smith, J. B. Redford, eds.), pp. 105–117. New York: Plenum Press 1973
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Gregory, J.E., Luff, A.R., Morgan, D.L. et al. The stiffness of amphibian slow and twitch muscle during high speed stretches. Pflugers Arch. 375, 207–211 (1978). https://doi.org/10.1007/BF00584245
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DOI: https://doi.org/10.1007/BF00584245