[Effect of the oxygen supply on the energetics of rat skeletal and heart muscle during perfusion].

In the isolated perfused preparations of the rat soleus muscle and heart, energy expenditure of resting organ was related to perfusion rate and oxygen delivery. In the resting soleus muscle, this relationship was present up to the oxygen delivery 60-100 nmol/(g.s) and absent at higher levels. In the resting heart, the relationship was shown up to 460 nmol/(g.s). The efficiency of contractions of the soleus muscle increased with oxygen delivery decreasing below 40-80 nmol/(g.s) with constant mechanical power. The idea of oxygen consumption independence of oxygen supply (Pflüger's postulate) seems not to be universally correct.