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. 1975 Oct;251(3):627–643. doi: 10.1113/jphysiol.1975.sp011112

Myocardial sarcomere dynamics during isometric contraction.

J W Krueger, G H Pollack
PMCID: PMC1348407  PMID: 1185677

Abstract

1. Sarcomere lengths were measured during rest and throughout the time course of isometric contractions in thin, isolated rat papillary muscles using light diffraction techniques. 2. Shortening of the sarcomere length occurred upon contraction at all muscle lengths, averaging 7% at optimal length and more at shorter lengths. Relative to the narrow range of sarcomere lengths spanning the length--tension curve, this degree of shortening was considerable. 3. Local changes of sarcomere length were quantitatively paralleled by local changes of tissue segment length, the latter demarcated by microspheres lodged within the muscle tissue. At all but the shortest muscle lengths, sarcomere shortening was fully accounted for by equivalent lengthening of the non-striated regions near the clamped ends of the preparation. 4. It seems likely that these regions near the clamped ends of the preparation. 4. It seems constitute the source of the large series elasticity characteristic of isolated papillary muscle preparations such as this.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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