Blood flow-limited oxygen consumption in resting cat skeletal muscle.

WHALEN, W.J., D. BUERK, AND CLAIRE ANN THUNING. Blood jlow-limited oxygen consumption in resting cat skeletal muscle. Am. J. Physiol. 224(4) : 763-768. 1973.-In isolated, autoperfused preparations of the cat soleus (n = 10) and gracilis (n = 9) muscles, blood flow and venous and tissue Po2 were measured at several levels of perfusion pressure. Oxygen consumption (Vo2, steadystate conditions) decreased significantly with a decrease in blood flow in all the experiments. Blood flow (ml/ 100 g per min) ranged from 5 to 94 in the soleus and from 0.5 to 8.0 in the gracilis. The corresponding ranges of vo 2 (ml/l 00 g per min) were 0.38.5 and 0.05-0.55. Of 218 measurements of tissue Po2 in the soleus muscle, only 24 were below 8 mm Hg and only 14 below 5 mm Hg. In the gracilis muscle, of 138 measurements of tissue Po2, nine were below 8 mm Hg and two were below 5 mm Hg. We conclude that hypoxia in the classical sense is not responsible for the decrease in Vo2 with decreasing blood flow.