Protective effects of aprotinin pretreatment on ischemia reperfusion injury to spinal cord of rabbits

Aim: The aprotinin has the function of protecting the blood platelet, decreasing lysis of fibrin, etc., which has applied to the operation on extracorporeal circulation vessels of heart. The aim of this paper is to observe the protective effect of aprotinin on spinal cord ischemia-reperfusion injury in rabbits. Methods: Twenty-seven domestic rabbits were randomly divided into aprotinin treatment group, ischemia groupand sham operation group with 9 rabbits in each group. The infrarenal segment in abdomial aorta was clamped for 30 minutes to build the model of ischemia of lumbosacral spinal cord in rabbits. Reperfusion was performed after the blood stream regained normal for 48 hours. Aprotinin was given 3 × 10⁷ IU/kg as a short intravenous injection for 10 minutes before ischemia, and then microhydrargyrum was injected by 1 × 10⁷ IU/kg per hour. The saline was used in ischemia group, and the occlusion and reperfusion time were the same as those of aprotinin treatment group. The animals of sham operation group were performed with midline laparotomy without aortic occlusion. The animals were monitored with somatosensory evoked potential (SEP) before ischemia, during ischemia and at 60 minutes after reperfusion. Their motor functions were scored. The animals were killed at 48 hours after reperfusion, and their spinal cords were tested with histopathological examination. Results: There was no obvious change of SEP in sham operation group, and all animals were recovered. The waves of ischemia group disappeared at 30 minutes of ischemia, and the waves of aprotinin treatment group reduced to 30%. After 60-minute reperfusion, the waves of aprotinin treatment and ischemia groups gradually increased to 72% and 53% of the initial amplitude (P < 0.01). The latencies of N1 and P1 of SEP were (28.5 ± 1.8) ms and (56.8 ± 2.9) ms, respectively at 60 minutes after reperfusion. There were significant differences compared with that before ischemia and saline groups (P < 0.05) . The neurological function score in aprotinin treatment group was significantly higher than that in ischemia group at 24 hours and 48 hours after reperfusion (P < 0.05). The count of normal nerve cells of spinal cord anterior horn in aprotinin treatment group was significantly higher than that in ischemia roup at 48 hours after reperfusion (P < 0.05). Conclusion: The aprotinin has the function of reducing spinal cord ischemia-reperfusion injury in rabbits and protecting the neurological function.