Study Of Inducible Nitric Oxide Synthase Inhibitor Aminoguanidine In Ischemia Reperfusion Injury Of Spinal Cord In Rabbits

Objective To study the protective effect of inducible nitric oxide synthase inhibitor aminoguanidine in ischemia reperfusion injury of spinal cord in rabbits.Methods Ischemia reperfusion model was established by clamping the aorta of rabbits just distal to the left renal artery for 30min followed by a reperfusion period of 24h.18 New Zealand white rabbits were randomly divided into sham-operated group(group A,n=4),control group(group B,n=7)and AG treated group(group C,n=7). Animals were treated with 100mg/kg AG(iNOS inhibitor) intravenously before the occlusion of aorta and intramusculy again 8h after the reperfusion in group C.The locomotor scores of hindlimbs in rabbits were evaluated after 24h of reperfusion and then all rabbits were sacrificed.The content of NO and activity of NOS in spinal cord were measured and the neuropathology changes of spinal cord were observed by light microscopy and electron microscopy.The apoptotic index of neurons in spinal cord was detected by TUNEL method and the expression of Bax and Bcl-2 proteins was examined by immunohistochemistry method.Result Compared with group A,the hindlimbs of rabbits were paralysed in group B after 24h reperfusion.The level of NO and the activity of NOS in spinal cord increased obviously.The apoptotic index of the spinal cord cells increased significantly.The expression of Bax protein increased obviously while the expression of Bcl-2 protein increased slightly.The pathology injury resulted from spinal cord ischemia reperfusion was seriously.Compared with group B,the locomotor scores of hindlimbs of rabbits were obviously elevated in group C.The level of NO and the activity of NOS in spinal cord in group C were lower than those in the group B.The apoptotic index of the spinal cord cells was decreased significantly.The expression of Bax protein was decreased and the expression of Bcl-2 protein was increased significantly.The pathology injury of the spinal cord was alleviated in group C.The differences between each group have statistics meanings(P<0.05).Conclusion Inducible nitric oxide synthase play a important role in ischemia reperfusion injury of spinal cord in rabbits.Inducible nitric oxide synthase inhibitor (aminoguanidine) could relieve spinal cord injury induced by ischemia reperfusion in rabbits.