ISSN:
1432-2013
Keywords:
Vascular smooth muscle
;
Smooth muscle: mechanics
;
Skinned fibres
;
Stiffness
;
Force-length relation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Vascular smooth muscle series elasticity was examined in living and glycerinated preparations as a function of the tissue length or calcium elicited force. Isometrically contracted smooth muscle strips were submitted to small quick stretches and releases (rise time 1.5 ms). The resulting immediate tension changes were proportional to the length changes for length steps ranging from −0.5% L0 to +2% L0. Plotting the immediate tension changes versus the length steps resulted in force-extension diagrams of the series elasticity (T1-curves). The linear parts of the T1-curves extrapolated to a common abscissa intercept of about −1% to −2% L0 irrespective of the tissue length or the degree of calcium activated force. The slopes of the T1-curves taken as the stiffness of the series elasticity increased in proportion to the isometric tension and depended on the tissue length or the degree of calcium activation in a similar way as tension. It is concluded that tension changes due to changes in the calcium concentration or the tissue length are caused by a change in the number of attached crossbridges. Results obtained in “skinned” fibres were similar to the one obtained in living fibres indicating that electromechanical coupling was not a major factor in determining the decrease in isometric tension and stiffness at short lengths.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00582921
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