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Role of Calcium and Crossbridges in Modulation of Rates of Force Development and Relaxation in Skinned Muscle Fibers

  • Jack A. Rall
  • Philip A. Wahr
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 453)

Abstract

The influence of Ca2+ and force generating crossbridges on the kinetics of force development and relaxation was examined in skinned muscle fibers activated by photolytic release of Ca2+ from a caged calcium or inactivated by photolytic uptake of Ca2+ by a caged Ca2+ chelator. In frog fibers at 10°C, decreasing the Ca2+ released from caged calcium to an extent that resulted in 50% of maximum force development produced an approximate seven-fold decrease in the rate of contraction. In contrast decreasing the number of force generating crossbridges by partial extraction of troponin C (TnC) or addition of vanadate caused only minor changes in contraction rate. Thus the rate of force development decreases dramatically with decreases in the Ca2+ level which suggests that a step in the crossbridge cycle may be Ca2+ dependent. The kinetics of relaxation induced by photolysis of diazo-2 was: a) slowed by stabilization of the sarcomeres by repeated releases and re-stretches during contraction and b) accelerated when the amplitude of force development was decreased by decreasing the [Ca2+] which induced a steady contraction. The half time of relaxation decreased by approximately two- to three-fold, when 50% of maximum force was developed. One interpretation of these results is that decreasing the number of force generating crossbridges may speed relaxation by inducing a decreased affinity of TnC for Ca2+ and thus accelerating the Ca2+ dissociation rate from TnC and thereby increasing relaxation rate.

Keywords

Force Development Thin Filament Partial Extraction Relaxing Solution Intact Fiber 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    Natori, R. Jikeikai Medical Journal 1, 119–126 (1954).Google Scholar
  2. 2.
    Wahr, P.A. & Rall, J.A. Am. J. Physiol. 272, C1664–C1671 (1997).PubMedGoogle Scholar
  3. 3.
    Wahr, P.A. & Rall, J.A. Biophys. J. 70, A38 (1996).CrossRefGoogle Scholar
  4. 4.
    Chase, P. B. & Kushmerick, M.J. Biophys. J. 53, 935–946 (1988).PubMedCrossRefGoogle Scholar
  5. 5.
    Hou, T.-T, Johnson, J.D., & Rall, J.A. J. Physiol. Lond. 441, 285–304 (1991).PubMedGoogle Scholar
  6. 6.
    Kaplan, J.H. & Ellis-Davies, G.C.R. Proc. Natl. Acad. Sci. USA 85, 6571–6575 (1988).PubMedCrossRefGoogle Scholar
  7. 7.
    Adams, S.R., Kao, J.P.Y., Grynkiewica, G., Minta, A. & Tsien, R.Y. J. Am. Chem. Soc. 110, 3212–3220 (1988).CrossRefGoogle Scholar
  8. 8.
    Adams, S.R., Kao, J.P.Y. & Tsien, R.Y. J. Am. Chem. Soc. 111, 7957–7968 (1989).CrossRefGoogle Scholar
  9. 9.
    Moss, R. L. Circ. Res. 70, 865–884 (1992).PubMedGoogle Scholar
  10. 10.
    Yates, L. D., Coby, R.L., Luo, Z, & Gordon, A.M. J. Muscle Res. Cell Motil. 14, 392–400 (1993).PubMedCrossRefGoogle Scholar
  11. 11.
    Brenner, B. Biophys. J. 41, 99–102 (1983).PubMedCrossRefGoogle Scholar
  12. 12.
    Metzger, J. M. & Moss, R.L..J. Gen. Physiol. 98, 233–248 (1991).PubMedCrossRefGoogle Scholar
  13. 13.
    Millar, N. C. & Homsher, E. J. Biol. Chem. 265, 20234–20240 (1990).PubMedGoogle Scholar
  14. 14.
    Chase, P. B., Martyn, D.A., Kushmerick, M.J., & Gordon, A.M. J. Physiol. Lond. 460, 231–246 (1993).PubMedGoogle Scholar
  15. 15.
    Dantzig, J.A. & Goldman, YE. J. Gen. Physiol. 86, 305–327 (1985).PubMedCrossRefGoogle Scholar
  16. 16.
    Edman, K.A.P. & Flitney, F.W. J. Physiol. Lond. 329, 1–20 (1982).PubMedGoogle Scholar
  17. 17.
    Huxley, A.F. & Simmons, R.M. Cold Spring Harbor Symp. Quant. Biol. 37, 669–680 (1972).CrossRefGoogle Scholar
  18. 18.
    Guth, K. & Potter, J.D.J. Biol. Chem. 262, 13627–13635 (1987).Google Scholar
  19. 19.
    Rennie, E. R., Johnson, J.D., Smillie, L.B. & Rall, J.A. Biophys. J. 72, A282 (1997).CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1998

Authors and Affiliations

  • Jack A. Rall
    • 1
  • Philip A. Wahr
    • 2
  1. 1.Department of PhysiologyOhio State UniversityColumbusUSA
  2. 2.Department of PhysiologyUniversity of MichiganUSA

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