The effects of hypertonic saline on spinal cord blood flow following compression injury

7.5% hypertonic saline was administered following spinal cord injury to tes t its effect on spinal cord blood flow. Four different groups of rats under went 10 minutes of spinal cord compression (45g) at the C3 to C5 levels. A fifth group was not injured, but received hypertonic saline (5 ml/kg) at 5, 15 and 60 minutes following injury. Somatosensory evoked potentials and sp inal cord blood flow were measured prior to and for 4 hours following the i njury. The administration of hypertonic saline caused a significant increas e in flow when administered 5 minutes following injury. Topical nitroprussi de administration did not cause any increase in spinal cord blood flow duri ng this time period. Hypertonic saline administration at the later time per iods did not increase spinal cord blood how. The group of animals which wer e not injured, but received hypertonic saline also showed no significant ch ange in flow. The somatosensory evoked response of the treated animals was maintained for 4 hours after the injury where as the untreated animals bega n to lose their evoked responses 3 hours after injury.