Protection of hyperbaric oxygenation for acute ischemic spinal cord re-perfusion injury in rabbits

Objective Based on a change of histopathology,biochemistry and MRI in rabbit models of acute ischemic spinal cord re-perfusion injury,the spinal injuried mechanism and protection of hyperbaric oxygenation(HBO) on spinal ischemic injury were studied.Methods The rabbit models of spinal cord ischemic injury were formed by occlusion of abdominal aorta in rabbits.After 40 min of spinal ischemia and re-perfusion,the lipid peroxide(LPO) level and superoxide dismutase(SOD) activity were measured;the disappeared degrees of denervation function,histopathology and MRI(L4 centrically) were observed,too.Results At post-spinal cord ischemia of 40 min,all animals got paralysis in their hind limbs(muscle-force II);LPO level raised and SOD activity reduced obviously,when compared with the normal control group(P0.05).The changes were returned to normal after 24h of re-perfusion.The abnormal alterations of histopathology and MRI were found in spinal ischemia period,particularly in re-perfusion.These experimental rabbits were treated with HBO therapy(inhaled 99.5% O 2,0.2 MPa,40 min).Result showed that LPO level decreased and SOD activity enhanced,there was a marked difference(P0.05). Conclusion It suggests that LPO is a main mechanism of spinal cord ischemia and re-perfusion injury.HBO therapy may enhance the SOD activity and reduce the formation of free radicals.So HBO has a protection against the acute ischemic spinal cord re-perfusion injury.