Vawda, F. and Geeves, M.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.
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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.
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:||19 Mar 2009 12:57|
|Resource URI:||http://kar.kent.ac.uk/id/eprint/16707 (The current URI for this page, for reference purposes)|
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