Regional spinal cord and brain blood flows in the rat

Regional spinal cord blood flow and blood flow in different brain areas were measured in 18 rats by the microsphere technique. By the use of spheres labeled with two different isotopes injected 5 min apart, double determinations were made. The consistency of the results from the two injections was very good. Blood flow was highest in the lumbar part of the spinal cord, somewhat lower in the lower thoracic part, lowest in the upper thoracic part, and again higher in the cervical cord; the mean values of the two determinations were 0.98, 0.74, 0.42, and 0.48 ml X min-1 X g-1 tissue for these regions, respectively. The brain areas investigated were the brain stem, cerebellum, and right and left hemispheres; the respective mean values of the two blood flow determinations in these areas were 0.54, 0.58, 0.33, and 0.38 ml X min-1 X g-1 tissue.