Influence of Anomalous Blood Viscosity on Resistance to Flow in the Dog's

Observations were made on an isolated hind leg preparation of dogs, perfused with blood and various homogeneous perfusates. A wide range of intravascular pressures were used while a constant arteriovenous pressure gradient was maintained. It was found that parallel increases in arterial and venous pressures result in a reduction in resistance to blood flow. A similar change in resistance is observed when more homogeneous perfusates are employed. Therefore, under the conditions of these experiments, the reduction in resistance with elevation of intni vascular pressure must be ascribed principally to passive clistention of the vascular bed.