Change of local spinal cord blood flow in acute ischaemia.

The local blood flow of the spinal cord was recorded by the hydrogen polarographic method with platinum electrodes. The blood flow and its changes were measured during acute ischaemia caused by compression of the thoracic aorta, and also after release of compression. Ten cats were included in these experiments, and more than 100 measurements were made in the lumbar region of the spinal cord. In the grey matter a high flow was observed in every case, resembling that in the cerebral cortex. Reduction of the lumen of the thoracic aorta by one half resulted in a 23%, and by three quarters in a 60-70% decrease in blood flow. With total occlusion there was practically entire cessation of flow. Rapid restitution of blood supply in the grey matter of the spinal cord caused a 65%, and in the white matter a 170% increase in blood flow due to reactive hyperaemia. Normal flow rates returned within 2-2.5 minutes.