[The rate of blood flow in the cerebral microvessels of rats with an elevated blood leukocyte count].

The effect of additional administration of leucocytes into the vascular bed upon average velocities of the blood flow in the brain cortex microvessels with the erythrocyte flow diameter 5-15 mu, was studied by means of cine-TV-technique in rats. The 25-55% increase of the leucocytes concentration did not change the average blood flow velocity in the vascular net equal to 1186 +/- 306.8 and 1152 +/- 280.0 mu, resp., neither did it change arterial pressure equal to 113 +/- 10 mm Hg. The leucocyte load, however, decelerated the blood flow velocity by 100-600 mu/sec in 45% of the vessels, accelerated it by 100-400 mu/sec in 36% and did not affect it in 19%. The data obtained suggest that the leucocyte load did not affect the resistance against blood flow in resistive vessels which control the blood flow in microvascular bed, but it led to a redistribution of the blood flow in the brain microcirculation system.