Pressure-flow relation of erythrocyte suspension in perfusion of bullfrog’s hind limb and marginal zone theory

The pressure-flow relationship of erythrocyte suspension in the bullfrog’s hind limb was studied by the perfusion method in which the rate of flow: pressure characteristic consists of a smooth curve convex to the pressure axis, tending to a straight line at a high rate of flow. This asymptotic line was found to have a negative intercept on the flow axis, which is independent of the haematocrit of the sample, and depended only on the radius of the vascular tube. In the light of the marginal zone theory, our finding appears appropriate.