Regional spinal cord blood flow in the rabbit, cat and monkey

Regional blood flow in the spinal cord was measured in rabbits, cats and monkeys with radioactively labelled microspheres. The reproducibility of the method was tested in rabbits by 3 consecutive determinations with differently labelled microspheres within the different cord regions, and was found to be good. In all 3 species, the blood flow was higher in the lumbar part of the cord than in the thoracic part, and in rabbits and monkeys it was also higher in the cervical than in the thoracic part. The flow values for the cervical, lower thoracic and lumbar parts of the cord in rabbits were 33.3, 24.7, and 27.3 ml X min-1 X 100 g-1, respectively, and in monkeys the respective figures were 14.9, 10.5 and 19.7 ml X min-1 X 100 g-1. Corresponding values for cats were only obtained during moderate hyperventilation, and were 12.2, 10.6, and 15.4 ml X min-1 X 100 g-1, respectively. The results are in good accordance with those of previous studies of the blood flow in the spinal cord in which other techniques have been employed.