| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Dipartimento de Scienze Fisiologiche, Università degli Studi di Firenze, Italy.
1. The relation between sarcomere length and steady tetanic tension was determined at 10-12 degrees C for 70-80 microns long length-clamped segments of single fibres isolated from the tibialis anterior muscle of the frog, in normal and hypertonic or hypotonic Ringer solutions. 2. The tension depression and potentiation observed in hypertonic and hypotonic Ringers solutions varied with sarcomere length, so that, as opposed to myofilament overlap predictions, the optimum length for tension development was shorter in hypertonic Ringer solution and longer in hypotonic Ringer solution than in normal Ringer solution. As the fibres were stretched from 1.96 to 2.24 microns sarcomere length, both tension depression in hypertonic Ringer solution and tension potentiation in hypotonic Ringer solution increased by 9 and 5%, respectively. 3. Within this range of sarcomere lengths the length-stiffness relation in hypotonic and in hypertonic Ringer solutions exhibit little or no change relative to that in normal Ringer solution. 4. The results indicate that separation between the thick and the thin myofilaments influences the mechanism of force generation. There is an optimum interfilament distance (10-12 nm surface to surface between the thick and the thin filaments) for tension production. In isotonic Ringer solution, this corresponds to the interfilament distance at sarcomere lengths around 2.10 microns. The force per attached cross-bridge, rather than their number, appears to decrease as the interfilament distance is brought above or below the optimum length. Even if this effect is moderate in isotonic Ringer solution, it should be taken into account in models of the force-generation mechanism.
This article has been cited by other articles:
|
|
 |
|
  Y. Shimamoto, F. Kono, M. Suzuki, and S. Ishiwata Nonlinear Force-Length Relationship in the ADP-Induced Contraction of Skeletal Myofibrils Biophys. J., December 15, 2007; 93(12): 4330 - 4341. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Colombini, M. A. Bagni, G. Romano, and G. Cecchi Characterization of actomyosin bond properties in intact skeletal muscle by force spectroscopy PNAS, May 29, 2007; 104(22): 9284 - 9289. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Linari, M. Caremani, C. Piperio, P. Brandt, and V. Lombardi Stiffness and Fraction of Myosin Motors Responsible for Active Force in Permeabilized Muscle Fibers from Rabbit Psoas Biophys. J., April 1, 2007; 92(7): 2476 - 2490. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Colombini, M. A. Bagni, G. Cecchi, and P. J. Griffiths Effects of solution tonicity on crossbridge properties and myosin lever arm disposition in intact frog muscle fibres J. Physiol., January 1, 2007; 578(1): 337 - 346. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. N. Ahn, K. Meijer, and R. J. Full In situ muscle power differs without varying in vitro mechanical properties in two insect leg muscles innervated by the same motor neuron J. Exp. Biol., September 1, 2006; 209(17): 3370 - 3382. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. A. Biewener and A. N. Ahn Tired of fatigue? Factors affecting the force-length relationship of muscle J Appl Physiol, July 1, 2006; 101(1): 5 - 6. [Full Text] [PDF]
|
|
|
|
 |
|
 W. R. Frontera, D. Suh, L. S. Krivickas, V. A. Hughes, R. Goldstein, and R. Roubenoff Skeletal muscle fiber quality in older men and women Am J Physiol Cell Physiol, September 1, 2000; 279(3): C611 - C618. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. M. MILLMAN The Filament Lattice of Striated Muscle Physiol Rev, April 1, 1998; 78(2): 359 - 391. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
