Oxygen consumption and blood flow in resting mammalian skeletal muscle.

DURAN, WALTER N., AND EUGENE M. RENKIN. Oxygen consumption and blood flow in resting mammalian skeletal mu&e. Am. J. Physiol. 226(l) : 173-l 77. 1974.-Of a total of 35 isolated blood-perfused, resting dog gracilis muscles, 25 maintained constant oxygen uptake (~oz) at all blood flows (Q) b a ove 2 ml/min X 100 g. In nine muscles, ~OZ varied with Q up to at least 10 ml/min x 100 g, reaching values up to 60 y0 above J?o, at Q = 3 ml/min x 100 g, which was the same as that of ,constant-Voz muscles. One muscle converted spontaneously from %z-dependent to &z-independent relation to flow. Constancy of vo2 was associated with the presence of resistance vessel autoregulation, particularly if transient response criteria for the latter were used. However, abolition of autoregulation by vasodilator drugs did not change the relation of 902 to 02 in any preparation. It is concluded that the Vog-Q relation at flows higher than 3 ml/min x 100 g does not depend on vascular autoregulation, but that it is a characteristic of muscle cell metabolism. Blood flow autoregulation may depend on a metabolic pattern which itself limits O2 uptake.