微小循環系の血流計測

ラット腸間膜の微小血管における圧-流量特性

抄録

Pressure-flow relationships in the microvasculature of the rat mesentery have been studied by the intravital microscopic technique in order to obtain fundamental hemodynamic data as the basis of microcirculatory mass transfer studies. Two-channel sample hold system for analyzing blood velocity on the monitor TV screen of microscopic images was newly developed.
Forty eight microvessels of 11 rats ranging from 4 to 24 micra in diameter were subjected to the measurement of blood velocity. Results showed that considerably good linear correlation existed between the blood velocity and arterial pressure. The pressure-flow relationships thus obtained from all microvessels were found to be classified into three major groups. Vessels of the first group showed 40 to 50 mmHg of aparent critical closing pressure (CCP). In these microvessels to-and-fro movement of blood flow was observed. The second group showed 5 to 20 mmHg of CCP, as is the case with most true capillaries. The third one showed negative CCP corresponding to the precapillaries or postcapillaries. These findings seem interesting since they suggest that close correlation exists between the functional flow behavior and the morphological dimensions of the microvessels.