TY - JOUR
T1 - In situ assessment of shortening and lengthening contractile properties of hind limb ankle flexors in intact mice
AU - Gorselink, M.
AU - Drost, M.R.
AU - de Louw, J.
AU - Willems, P.J.B.
AU - Hesselink, M.K.C.
AU - Dekkers, E.C.A.
AU - Rosielle, N.
AU - van der Vusse, G.J.
PY - 2001/6/6
Y1 - 2001/6/6
N2 - The availability of animal models with disrupted genes has increased the need for small-scale measurement devices. Recently, we developed an experimental device to assess in situ mechanical properties of isometric contractions of intact muscle complexes of the mouse. Although this apparatus provides valuable information on muscle mechanical performance, it is not appropriate for determining contractile properties during shortening and lengthening contractions. In the present study we therefore developed and evaluated an experimental apparatus for assessment of shortening and lengthening contractile properties of intact plantar and dorsal flexors of the mouse. The current through a custom-built, low-inertia servomotor was measured to assess contractile muscular torque ranging from -50 to +50 mN·m. Evaluation of the fixation procedure of the animal to the apparatus via 3-D monitoring of the muscle-tendon complex length showed that the additional shortening in length due to a contraction with maximal torque output has only minor effects on the measured torque. Furthermore, misalignment of the axis of rotation of the apparatus relative to the axis of rotation in the ankle joint, i.e. eccentricity, during a routine experiment was estimated to be less than 1.0 mm and hence did not influence the measured torque output under our experimental conditions. Peak power per unit muscle mass (mean±SD) of intact dorsal and plantar flexors was 0.27±0.02 and 0.19±0.03 W·g-1, respectively. The angular velocity at maximal peak power generated by the dorsal flexor complex and the plantar flexor complex was 1100±190 and 700±90 °·s-1, respectively.
AB - The availability of animal models with disrupted genes has increased the need for small-scale measurement devices. Recently, we developed an experimental device to assess in situ mechanical properties of isometric contractions of intact muscle complexes of the mouse. Although this apparatus provides valuable information on muscle mechanical performance, it is not appropriate for determining contractile properties during shortening and lengthening contractions. In the present study we therefore developed and evaluated an experimental apparatus for assessment of shortening and lengthening contractile properties of intact plantar and dorsal flexors of the mouse. The current through a custom-built, low-inertia servomotor was measured to assess contractile muscular torque ranging from -50 to +50 mN·m. Evaluation of the fixation procedure of the animal to the apparatus via 3-D monitoring of the muscle-tendon complex length showed that the additional shortening in length due to a contraction with maximal torque output has only minor effects on the measured torque. Furthermore, misalignment of the axis of rotation of the apparatus relative to the axis of rotation in the ankle joint, i.e. eccentricity, during a routine experiment was estimated to be less than 1.0 mm and hence did not influence the measured torque output under our experimental conditions. Peak power per unit muscle mass (mean±SD) of intact dorsal and plantar flexors was 0.27±0.02 and 0.19±0.03 W·g-1, respectively. The angular velocity at maximal peak power generated by the dorsal flexor complex and the plantar flexor complex was 1100±190 and 700±90 °·s-1, respectively.
KW - Contractile work
KW - In situ
KW - Mice
KW - Shortening contraction
KW - Skeletal muscle
UR - http://www.scopus.com/inward/record.url?scp=0035006884&partnerID=8YFLogxK
U2 - 10.1007/s004240100554
DO - 10.1007/s004240100554
M3 - Article
C2 - 11417229
AN - SCOPUS:0035006884
SN - 0031-6768
VL - 442
SP - 304
EP - 311
JO - Pflügers Archiv : European Journal of Physiology
JF - Pflügers Archiv : European Journal of Physiology
IS - 2
ER -