Beckers-Bleukx, G.
Maréchal, Georges
[UCL]
(eng)
Soleus (n=57) muscles and Extensor digitorum longus (n=24) muscles of NMRI mice were
tetanically stimulated at 20°± 0.1°C and released at controlled velocities, such that the
force maintained during the release varied between 98 and 15% of the maximal isometric force
(F0). The data were fitted to a Hills hyperbola [F0 + a/F0)(V + b) = b(1 + a/Fo)l by a nonlinear
least square method and the maximum mechanical power, Pw (µW/mm3), was computed as [b.F0.(1 +
2a/F0 - 2„/(a/F0)2 + a/F0]. The myosin heavy chains (myosin heavy chain 1, 2A and 2B: MHC1,
MHC2A, MHC2B) of a crude extract in a Guba-Straub solution were separated by electrophoresis
on glycerol SDS-PAA gels and quantified (in % of total myosin) by densitometry. We tested by
a triple linear regression the hypothesis that Pw is determined by the relative proportions
of the myosin heavy chains. The mechanical power estimated from the regression is equal to:
Pwz = 1.49(±0.10)[MHC2B] + 0.26(±0.19)[MHC2A] + 0.15(±0.10)[MHC1].
The correlation between Pw and Pwz equals 0.86 (n=81). We conclude that the content in myosin
heavy chains account for 74% (=0.862) of the variance of the maximum mechanical power.
Bibliographic reference |
Beckers-Bleukx, G. ; Maréchal, Georges. Maximal Mechanical Power and Myosin Heavy-chains of Mouse Muscles.In: Journal of Muscle Research and Cell Motility, Vol. 11, no. 1, p. 71-71 (1990) |
Permanent URL |
http://hdl.handle.net/2078.1/63812 |