Abstract
1. Single muscle fibres of the frog were stretched during tetanus and filmed down the interference microscope. 2. Sarcomere lengths and A- and I-band widths were measured from cine films taken of the experimental sequences. 3. When a fibre was stretched during a tetanus, its A-band widths remained constant while its I-band widths changed according to the extent of the stretch. This behaviour is identical with that of a fibre stretched at rest. 4. Sarcomere lengths remained uniform along the fibre during a tetanus plus stretch, increasing as the I-band widths increased when the fibre was stretched. 5. At sarcomere lengths longer than LPmax (the length corresponding to greatest isometric tetanus tension) where the isometric tension diminishes as the fibre is lengthened, if the stretch was imposed during a tetanus the tension was higher after the stretch than before, showing a plateau which lasted for the duration of the tetanus. 6. This effect increased with longer sarcomere lengths and was not due to increased resting tension.
Full text
PDF
Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- ABBOTT B. C., AUBERT X. M. Changes of energy in a muscle during very slow stretches. Proc R Soc Lond B Biol Sci. 1951 Dec 31;139(894):104–117. doi: 10.1098/rspb.1951.0049. [DOI] [PubMed] [Google Scholar]
- ABBOTT B. C., AUBERT X. M. The force exerted by active striated muscle during and after change of length. J Physiol. 1952 May;117(1):77–86. [PMC free article] [PubMed] [Google Scholar]
- Curtin N. A., Davies R. E. Very high tension with very little ATP breakdown by active skeletal muscle. J Mechanochem Cell Motil. 1975;3(2):147–154. [PubMed] [Google Scholar]
- Edman K. A., Elzinga G., Noble M. I. Proceedings: Force enhancement induced by stretch of contracting single isolated muscle fibres of the frog. J Physiol. 1976 Jun;258(2):95P–96P. [PubMed] [Google Scholar]
- HUXLEY A. F. A high-power interference microscope. J Physiol. 1954 Jul 28;125(1):11–3P. [PubMed] [Google Scholar]
- HUXLEY A. F., NIEDERGERKE R. Measurement of the striations of isolated muscle fibres with the interference microscope. J Physiol. 1958 Dec 30;144(3):403–425. doi: 10.1113/jphysiol.1958.sp006110. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Katz B. The relation between force and speed in muscular contraction. J Physiol. 1939 Jun 14;96(1):45–64. doi: 10.1113/jphysiol.1939.sp003756. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sugi H. Tension changes during and after stretch in frog muscle fibres. J Physiol. 1972 Aug;225(1):237–253. doi: 10.1113/jphysiol.1972.sp009935. [DOI] [PMC free article] [PubMed] [Google Scholar]