Biophysical Journal 39: 189-196 (1982)
© 1982 the Biophysical Society

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Morgan, D L Articles by Julian, F J Search for Related Content PubMed PubMed Citation Articles by Morgan, D L Articles by Julian, F J

A quantitative model of intersarcomere dynamics during fixed-end contractions of single frog muscle fibers.

ABSTRACT

A numerical model of a muscle fiber as 400 sarcomeres, identical except for their initial lengths, was used to simulate fixed-end tetanic contractions of frog single fibers at sarcomere lengths above the optimum. The sarcomeres were represented by a lumped model, constructed from the passive and active sarcomere length-tension curves, the force-velocity curve, and the observed active elasticity of a single frog muscle fiber. An intersarcomere force was included to prevent large disparities in lengths of neighboring sarcomeres. The model duplicated the fast rise, slow creep rise, peak, and slow decline of tension seen in tetanic contractions of stretched living fibers. Decreasing the initial non-uniformity of sarcomere length reduced the rate of rise of tension during the creep phase, but did not decrease the peak tension reached. Limitations of the model, and other processes that might contribute to the shape of the fixed end tetanic tension record are discussed. Taking account of model and experimental results, it is concluded that the distinctive features of the tension records of fixed end tetanic contraction at lengths beyond optimum can be explained by internal motion within the fiber.

This article has been cited by other articles:

				D. E. Rassier, B. R. MacIntosh, and W. Herzog Length dependence of active force production in skeletal muscle J Appl Physiol, May 1, 1999; 86(5): 1445 - 1457. [Abstract] [Full Text] [PDF]