Neuroprotective Effect of Ulinastatin on Spinal Cord Ischemia-Reperfusion Injury in Rabbits

Ulinastatin (UTI), a trypsin inhibitor, is isolated and purified from human urine and has been shown to exert protective effect on myocardial ischemia reperfusion injury in patients. The present study was aimed at investigating the effect of ulinastatin on neurologic functions after spinal cord ischemia reperfusion injury and the underlying mechanism. The spinal cord IR model was achieved by occluding the aorta just caudal to the left renal artery with a bulldog clamp. The drugs were administered immediately after the clamp was removed. The animals were terminated 48 hours after reperfusion. Neuronal function was evaluated with the Tarlov Scoring System. Spinal cord segments between L-2 and L-5 were harvested for pathological and biochemical analysis. Ulinastatin administration significantly improved postischemic neurologic function with concomitant reduction of apoptotic cell death. In addition, ulinastatin treatment increased SOD activity and decreased MDA content in the spinal cord tissue. Also, ulinastatin treatment suppressed the protein expressions of Bax and caspase-3 but enhanced Bcl-2 protein expression. These results suggest that ulinastatin significantly attenuates spinal cord ischemia-reperfusion injury and improves postischemic neuronal function and that this protection might be attributable to its antioxidant and antiapoptotic properties.