[Microcalorimetric and myographic analysis of the causes of changes in the ratio of heat loss to work accomplished during muscular activity].

In the frog non-fatigued sartorius muscle, raise of the ratio of muscle-emanated heat to the performed mechanical work is due to the aerobic delayed heat production. The heat emanation reflects the respiratory resynthesis of macroergs used for subsequent contractile muscle activity. Contrary to that, raise of the ratio in fatigued muscle reflects the excitation-contraction coupling disturbance and a specific increase of the energy supply for excitable link.