Force generation upon hydrostatic pressure release in tetanized intact frog muscle fibres

Vawda, Farouk and Geeves, Michael A. and Ranatunga, K.W. (1999) Force generation upon hydrostatic pressure release in tetanized intact frog muscle fibres. Journal of Muscle Research and Cell Motility, 20 (5-6). pp. 477-488. ISSN 0142-4319. (The full text of this publication is not available from this repository)

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Official URL
http://dx.doi.org/10.1023/A:1005565917768

Abstract

Single intact muscle fibres isolated from the tibialis anterior muscle of the frog were exposed to hydrostatic pressures of 1-10 MPa, at 2-4 degrees C and sarcomere length of 2.1-2.2 mu m. The pressure was rapidly released (ca. 1 ms) to atmospheric level (0.1 MPa) during the plateau of a tetanic contraction (P-o) and the resultant tension ( =force) transient examined. The pressure release induced tension transient consisted of an initial tension drop coincident with pressure release (ca. 4% P-o per MPa, Phase 1), followed by a rapid recovery (Phase 2a) and a slower rise of tension (Phase 2b). Phase 1 was partly due to a length release at fibre ends (ca. 0.1 nm per half-sarcomere per MPa) induced by pressure-release effects on the steel chamber and fibre attachments, and partly due to 'expansion' upon pressure release within muscle fibre (ca. 0.2 nm per half-sarcomere per MPa), probably in the myofilaments and cross-bridges. The rate of tension recovery during phase 2a (ca. 600/s) was comparable to that of the quick tension recovery (T-1-T-2 transition) reported from moderately fast small length releases; the time course of Phase 2b (rate ca. 40/s) was similar to the late phase of tension rise in a tetanus, and hence compared with Phase 4 (T-4) of a length release tension transient. Results are compared with the previously reported findings from analogous experiments on Ca2+-activated skinned (rabbit) muscle fibres.

Item Type: Article
Subjects: Q Science
Q Science > QH Natural history > QH301 Biology
Divisions: Faculties > Science Technology and Medical Studies > School of Biosciences
Depositing User: F.D. Zabet
Date Deposited: 19 Mar 2009 12:57
Last Modified: 17 Jul 2014 08:31
Resource URI: http://kar.kent.ac.uk/id/eprint/16707 (The current URI for this page, for reference purposes)
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