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Science 23 August 1963:
Vol. 141. no. 3582, pp. 712 - 713
DOI: 10.1126/science.141.3582.712
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Articles

Mechanism of Supercontraction in a Striated Muscle Fiber

Graham Hoyle 1 and James H. McAlear 2

1 Department of Biology, University of Oregon, Eugene
2 Electron Microscope Laboratory, University of California, Berkeley

Cross-striated muscle fibers may contract reversibly to less than 30 percent of their rest length and it is not easy to reconcile this fact with the sliding filament model of muscular contraction. The mechanism of supercontraction has been studied in fibrils obtained from the giant muscle fibers of the barnacle Balanus nubilus. They were examined by phase-contrast light microscopy and electron microscopy. Contraction beyond the 50-percent stage was found to be achieved largely by the passage of thick filaments through the Z-disks, which are perforated. The overlap of thick filaments from adjacent sarcomeres causes the appearance of the contraction bands about the Z-disks. Subsequent contraction is associated with a folding and loose coiling, but not a shortening, of the thick filaments.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Supercontracting muscle: producing tension over extreme muscle lengths.
A. Herrel, J. J. Meyers, J.-P. Timmermans, and K. C. Nishikawa (2002)
J. Exp. Biol. 205, 2167-2173
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Z Disc Ultrastructure in Scutal Depressor Fibers of the Barnacle.
R. A. Leyton and W. C. Ullrick (1970)
Science 168, 127-128
   Abstract »    PDF »
Contraction-Band Formation in Barnacle Myofibrils.
R. J. Baskin and G. M. Wiese (1964)
Science 143, 134-136
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Science. ISSN 0036-8075 (print), 1095-9203 (online)