Ischemia/Reperfusion After Spinal Cord Injury

Backgroundspinal cord injury has a high incidence, resulting in serious consequences, not only bring physical and psychological problems, but also bring many family and society problems. The mechanism and the process of spinal cord injury has been gradually revealed, and the development of drug treatment has achieved some success, but we still need some effective and inexpensive drugs.A number of mechanisms happened in spinal cord injury and ischemia/reperfusion injury is particularly concerned. I/R injury plays an important role both in the spinal cord injury and other iatrogenic injuries. MP and GM-1 were recommended as a treatment after spinal cord injury, but their application in clinical often bring many potential complications. According to the pharmacological characteristics and economic costs of MP, combined with extensive effect of vitamin C in the body, the co-application may be a good choice, and to avoid potential complications. And some patients (1.5% -3%) can occur with unexplained loss of spinal function after received spinal decompression surgery, some researchers hold the opinion that it was caused by I/R injury happened in decompression tissue. Compare the efficacy of MP alone with co-application of vitamin C combined with MP, investigate I/R injury after decompression of chronic spinal cord compression, discuss the injury mechanism.Objective1 To investigate the protection of co-application of low dose MP and ascorbic acid in I/R model.2 To investigate I/R injury after spinal cord decompression.Materials and methodsPart 1 The protection of co-application MP and ascorbic acid in acute spinal cord I/R injury modelSpinal cord ischemia model was induced by clamping the infrarenal aortic for 25 min. 144 New Zealand white rabbits were randomized as follows: A(negative control group),B(I/R group),C(low-dose MP),D(Vc),E(high-dose MP group),F(MP+Vc).Each group was given the corresponding disposal. The neurological score,MDA,SOD,CAT,GDH-Px levels were detected at different time point;H&E and Tunel stains were observed at 48h.Part 2 Ischemia / reperfusion injury after decompression in chronic spinal cord compression96 New Zealand white rabbits were randomized as follows: A (negative control group), B(I/R group), C(Decompression group). MDA,SOD,CAT,GDH-Px were detected at 0h, 30min, 6h, 12h, 24h, 48h. Apoptosis cell numbers were analysis at 0h and 48h.Results Part 1: MDA,SOD,CAT,GDH-Px levels in groupA,E,F at different time were significantly decreased. but there were no significant difference among group A,E,F;Tarlov scores of group E,F show significantly increase compared with group C and D;And H&E and Tunel stains show group E and F have the similar injury extent during I/R compared with group B,C and D.Part 2: MDA,SOD,CAT and GSH-Px levels in group B were significantly increased compared with group A at 30min, 6h, 12h, 24h, the levels in Group C were significantly increased compared with group A at each time point, and there were no difference in group C; Tunel stain shows the apoptosis cell number has no significant difference between 0h and 48h in group C.Conclusions1 The co-application of low dose MP and ascorbic acid shows the same therapeutic effect to spinal cord ischemia-reperfusion compared with large dose MP.2 There were no significant I/R injury after spinal cord decompression, I/R injury was not the cause of disfunction after spinal cord decompression.