Abstract
1. Single twitch fibres were dissected from anterior tibial muscles of the frog, Rana pipiens, and were then either chemically or mechanically skinned. Short segments of the skinned fibres were transferred to an experimental chamber and mounted between a force transducer and a stationary wire. 2. The average sarcomere length was determined from light photomicrographs of the segments obtained during activation and while relaxed. Activations were maximal, in solutions of pCa 5.49 and at 5 degrees C. Fibre segments having regions in which the striation pattern was highly non-uniform were rejected. 3. The relationship between tension and average sarcomere length was determined for sarcomere lengths between 2.1 and 3.8 micrometer. Tension always decreased when sarcomere length was increased above about 2.2 micrometer. Tension plotted against over-all average sarcomere length lay above data obtained from living fibres by Gordon, Huxley & Julian (1966a, b). 4. Good agreement with living fibre results was found when tension was plotted against the shortest average sarcomere length within a portion of the segment. 5. These findings indicate that sarcomere length non-uniformities greatly influence the shape of the sarcomere length-tension relation in skinned fibres at long lengths. In addition, no evidence was found for a length-dependent influence of calcium on tension development at long lengths during maximal activation.
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- Gordon A. M., Huxley A. F., Julian F. J. Tension development in highly stretched vertebrate muscle fibres. J Physiol. 1966 May;184(1):143–169. doi: 10.1113/jphysiol.1966.sp007908. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gordon A. M., Huxley A. F., Julian F. J. The variation in isometric tension with sarcomere length in vertebrate muscle fibres. J Physiol. 1966 May;184(1):170–192. doi: 10.1113/jphysiol.1966.sp007909. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HUXLEY A. F., PEACHEY L. D. The maximum length for contraction in vertebrate straiated muscle. J Physiol. 1961 Apr;156:150–165. doi: 10.1113/jphysiol.1961.sp006665. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hellam D. C., Podolsky R. J. Force measurements in skinned muscle fibres. J Physiol. 1969 Feb;200(3):807–819. doi: 10.1113/jphysiol.1969.sp008723. [DOI] [PMC free article] [PubMed] [Google Scholar]
- IWANAMI M., OSIBA S., YAMADA T., YOSHIMURA H. Seasonal variations in serum inorganic phosphate and calcium with special reference to parathyroid activity. J Physiol. 1959 Dec;149:23–33. doi: 10.1113/jphysiol.1959.sp006322. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Julian F. J., Morgan D. L. Intersarcomere dynamics during fixed-end tetanic contractions of frog muscle fibres. J Physiol. 1979 Aug;293:365–378. doi: 10.1113/jphysiol.1979.sp012894. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Julian F. J., Sollins M. R., Moss R. L. Sarcomere length non-uniformity in relation to tetanic responses of stretched skeletal muscle fibres. Proc R Soc Lond B Biol Sci. 1978 Jan 24;200(1138):109–116. doi: 10.1098/rspb.1978.0009. [DOI] [PubMed] [Google Scholar]
- Julian F. J. The effect of calcium on the force-velocity relation of briefly glycerinated frog muscle fibres. J Physiol. 1971 Oct;218(1):117–145. doi: 10.1113/jphysiol.1971.sp009607. [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]
- Moss R. L. Sarcomere length-tension relations of frog skinned muscle fibres during calcium activation at short lengths. J Physiol. 1979 Jul;292:177–192. doi: 10.1113/jphysiol.1979.sp012845. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rüdel R., Zite-Ferenczy F. Do laser diffraction studies on striated muscle indicate stepwise sarcomere shortening? Nature. 1979 Apr 5;278(5704):573–575. doi: 10.1038/278573a0. [DOI] [PubMed] [Google Scholar]
- Schoenberg M., Podolsky R. J. Length-force relation of calcium activated muscle fibers. Science. 1972 Apr 7;176(4030):52–54. doi: 10.1126/science.176.4030.52. [DOI] [PubMed] [Google Scholar]
- ter Keurs H. E., Iwazumi T., Pollack G. H. The sarcomere length-tension relation in skeletal muscle. J Gen Physiol. 1978 Oct;72(4):565–592. doi: 10.1085/jgp.72.4.565. [DOI] [PMC free article] [PubMed] [Google Scholar]