Control of the force-velocity relation by myosin heavy chains in mouse soleus and EDL muscle
(1994) Sarcomeric myosins: structure, function and dysfunction — Location: Venice San Servolo, Italy (22.September.1994)
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- Authors
Maréchal, Georges 
- Abstract
- The force velocity relation is described by three parameters: So, the maximum isometric stress (in mN/mm2), a/So, the force constant, and b, the velocity constant (in mm/s per mm of muscle length). The ratio b / (a/So) is the maximum velocity of contraction, Vmax. It is widely accepted that Vmax is controlled by the type of myosin heavy chains (MHC). We tested the hypothesis that MHC also controls the force constant. Mouse soleus muscles (n=108) and EDL muscles (n=83) were tetanized isometrically at 20°C and released at controlled velocities during the tetanus. The parameters of the force-velocity relation were computed using the Gauss-Newton method. The proportions of myosin heavy chains were measured by quantitative SDS-PAGE. The type of MHC controls Vmax but not a/So. Since a/So completely determines the normalized maximum power M2, it follows that M2 is not dependent on the type of myosin heavy chain: it must be controlled by an as yet unidentified factor.
Citations
Maréchal, G., & Beckers-Bleukx, G. (1994). Control of the force-velocity relation by myosin heavy chains in mouse soleus and EDL muscle. In Schiaffino, S. Reggiani, C. (ed.), Sarcomeric myosins: structure, function and dysfunction (International School of Neurological Science, p. p. 36). Schiaffino, S. Reggiani, C. https://hdl.handle.net/2078.5/230965