Abstract: Objective To observe the effect of aprotinin preconditioning on nitric oxide (NO), nitric oxide synthase (NOS) and oxyradical during spinal cord ischemia-reperfusion injury in rabbits.Methods 21 rabbits were randomly divided into the aprotinin treatment group (8 rabbits), control group (8 rabbits) and sham operative group (5 rabbits). The infrarenal segment in abdominal aorta was clamped for 60 min to construct the model of lumbosacral spinal cord ischemia in rabbits. Reperfusion was followed and kept on for 24 h until the blood flow regained normal. In the treatment group, aprotinin was given at 3×10⁷ IU/kg as a short time intravenous injection for 10 min before ischemia, and then was drilled with micro pump by 1×10⁷ IU/kg/h. Normal saline was used in the control group, the ischemia-reperfusion duration between aprotinin treatment group and control group remained same. The sham operative group was only exposured abdominal aorta and not clamped. The rabbits were killed before ischemia and 8 h, 24 h after ischemia-reperfusion, lumbar segment was harvested to detect content of NO, malondialdehyde (MDA), induced nitric oxide synthase (iNOS) and superoxide dismutase (SOD) of spinal cord.Results 8 h after spinal cord ischemia-reperfusion, compared with the control group, the content of NO, MDA and the activity of iNOS were less, and the activity of SOD was more in the aprotinin treatment group ( P<0.05).Conclusion Aprotinin pretreatment can reduce the content of NO, MDA and descend the activity of NOS. Moreover aprotinin pretreatment can ascend the activity of SOD and improve apoptosis of nerve cell.

Key words: aprotinin, spinal cord, ischemia-reperfusion, nitric oxid, nitric oxide synthase, malondialdehyde, superoxide dismutase