Pflügers Archiv

, Volume 407, Issue 4, pp 456–460 | Cite as

Active force as a function of filament spacing in crayfish skinned muscle fibers

  • Ernest W. April
  • David W. Maughan
Heart, Circulation, Respiration and Blood; Environmental and Exercise Physiology


Filament spacing is shown to have a pronounced effect on active force in skinned striated muscle fibers of crayfish. At constant filament overlap and constant ionic strength, the separation between the myofilaments (measured by low-angle X-ray diffraction) was adjusted by application of osmotic pressure. Force was induced by a calcium-containing activating solution. In the absence of compression, calcium-activated force in skinned fibers was approximately 80% of that in normal intact fibers. In fibers compressed somewhat beyond the dimension of intact fibers, force was maximal. With further compression, force was reduced and then abolished. The filament spacing-force relation reported here suggests that, at any instant, the distance between the myosin filaments and actin filaments affects either (a) the axial force per cross bridge or, more likely, (b) the number of cross bridges in the force-generating state.

Key words

Skinned muscle fibers Osmotic compression X-ray diffraction Filament spacing Muscle force Filament spacing-force relation Sarcomere length-force relation Ionic strength 


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  1. Aldoroty RA, April EW (1982) Microelectrode measurement of A-band Donnan potentials as a function of relative volume. Biophys J 37:121aGoogle Scholar
  2. Aldoroty RA, April EW (1984) Donnan potential from striated muscle liquid crystals. A-band and I-band measurements. Biophys J 46:769–779Google Scholar
  3. Aldoroty RA, Garty NB, April EW (1986) Donnan potentials from striated muscle liquid crystals: Lattice spacing dependence. Biophys J (in press)Google Scholar
  4. April EW (1969) The effects of tonicity and ionic strenght on tension and filament lattice volume in single muscle fibers. PhD Thesis, Columbia UniversityGoogle Scholar
  5. April EW (1980) Interfilament spacing changes in striated muscle during cross-bridge interaction. Fed Proc 39(6):1963Google Scholar
  6. April EW, aldoroty RA (1986) Donnan potentials generated by the surface charge on muscle filaments. In: Blank M (ed) Electrical double layers in biology. Plenum Press, New York, p 287Google Scholar
  7. April EW, Brandt PW (1973) The myofilament lattice: studies on isolated fibers. III. The effect of filament spacing upon tension. J Gen Physiol 61:490–508Google Scholar
  8. April EW, Maughan DW (1982) Correlation between interfilament spacing and force generation in striated muscle. Biophys J 37(2):129aGoogle Scholar
  9. April EW, Schreder J (1979) Role of osmotic forces in myofilament lattice stability in striated muscle. Biophys J 25:18aGoogle Scholar
  10. April EW, Brandt PW, Reuben JP, Grundfest H (1968) Muscle contraction: the effect of ionic strength. Nature 220:182–184Google Scholar
  11. April EW, Brandt PW, Elliott GF (1971) The myofilament lattice: studies on isolated fibers. I. The constancy of the unit-cell volume with variation in sarcomere length in a lattice in which the thin-to-thick myofilament ratio is 6:1. J Gen Physiol 51(1):72–82Google Scholar
  12. Boyle PJ, Conway EJ (1941) Potassium accumulation in muscle and associated changes. J Physiol 100:1–63Google Scholar
  13. Edman KAP, Anderson KE (1968) The variation in active tension with sarcomere length in vertebrate single muscle and its relation to fiber width. Experientia 24:134–136Google Scholar
  14. Eisenberg E, Moos C (1970) Actin activation of heavy meromyosin adenosine triphosphatase. J Biol Chem 245:2451–2456Google Scholar
  15. Godt RE, Maughan DW (1977) Swelling of skinned muscle fibers of the frog: experimental observations. Biophys J 19:103–116Google Scholar
  16. Godt RE, Maughan DW (1981) Influence of osmotic compression on calcium activation and tension in skinned muscle fibers of the rabbit. Pflügers Arch 391:334–337Google Scholar
  17. Gordon AM, Huxley AF, Julian FJ (1966) Variation in isometric tension with sarcomere length in vertebrate muscle fibers. J Physiol 184:170–192Google Scholar
  18. Gordon AM, Godt RE, Donaldson SKB, Harris CE (1973) Tension in skinned frog muscle fibers in solutions of varying ionic strength and neutral salt composition. J Gen Physiol 62:550–574Google Scholar
  19. Gulati J, Babu A (1982) Tonicity effects on intact single muscle fibers: relation between force and cell volume. Science 215: 1109–1112Google Scholar
  20. Gulati J, Babu A (1985) Critical dependence of calcium-activated force on width in highly compressed skinned fibers of the frog. Biophys J 48:781–787Google Scholar
  21. Hawkins RJ, April EW (1981) X-ray measurements of the bulk modulus of the myofilament liquid-crystal in striated muscle. J Mol Crystals Liquid Crystals 75:211–216Google Scholar
  22. Hawkins RJ, April EW (1983) The planar deformation behavior of skinned striated muscle fibers. J Mol Crystals Liquid Crystals 101:315–328Google Scholar
  23. Kawai M, Schulman MI (1985) Crossbridge kinetics in chemicallyskinned rabbit psoas fibres when the actin-myosin lattice spacing is altered by dextran T-500. J Mus Res Cell Motility 6:313–332Google Scholar
  24. Krasner B, Maughan D (1984) The relationship between ATP hydrolysis and active force in compressed muscle fibers. Pflügers Arch 400:160–165Google Scholar
  25. Maughan DW, Godt RE (1981) Inhibition of force production in compressed skinned muscle fibers of the frog. Pflügers Arch 390:161–163Google Scholar
  26. Matsubara I, Goldman YE, Simmons RM (1984) Changes in the lateral filament spacing of skinned muscle fibers when crossbridges attach. J Mol Biol 173:15–33Google Scholar
  27. Pollack GH (1983) The cross-bridge theory. Physiol Rev 63(3):1049–1113Google Scholar
  28. Schoenberg M (1980) Geometrical factors influencing muscle force development. I. The effect of filament spacing upon axial forces. Biophys J 30:51–68Google Scholar
  29. Shapiro PJ, Tawada K, Podolsky RJ (1979) X-ray diffraction of skinned muscle fibers. Biophys J 25(2):18aGoogle Scholar

Copyright information

© Springer-Verlag 1986

Authors and Affiliations

  • Ernest W. April
    • 1
  • David W. Maughan
    • 2
  1. 1.Department of Anatomy and Cell BiologyColumbia UniversityNew YorkUSA
  2. 2.Department of Physiology and BiophysicsUniversity of VermontBurlingtonUSA

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