Effects Of Lidocaine On Leukocytic Inflammation And Free Radical Reaction After Acute Spinal Cord Injury

There is a series of pathological and physiological changes after acute spinal cord injury (ASCI) in which neutrophils play a great role in it. Neutropils exist mainly in tissues which are bleeding or necrotic after ASCI. After ASCI, a great quantity of leucocytes exfiltrate and micro blood vessels spasm which can induce ischemic perfusion. If it continues, the structures of blood vessels'wall( VW) would be destroyed and much more leukocytes were exfiltrated, releasing active materials and various kinds of organized enzyme which can dissolve spinal cord tissues, so the function of antiinflammation can reduce the necrotic tissues. It is of great significance to inhibit inflammation after ASCI which can contribute to the spinal cord function recovery. In the same time, the free radical reaction is also play a role in the second injury after ASCI. Several studies report that lidocaine can protect the blood vessel, and some studies also show that lidocaine can inhibit the delivery of leukocyte to the contused brain tissues. However, there is no studies on whether lidocaine has the same functions on contused spinal cord tissues after ASCI.ObjectiveLidocain is injected into abdominal cavity after ASCI once a day. AT 6hours,3 days , 7days after ASCI, the specimen of the contused spinal cord were removed for analysis. We compare MPO value and SOD value between the control - group and the treated - group. Meanwhile the functional scores of the rats are recorded to approach the functions of lidocaine in the local leucocytic inflammation and the free radical reaction of contused spinal cord tissue.Methods36 animal models of acute spinal cord injury were established through free - fall impacting( modified Aliens method). The animals were separated into two groups by random. In the treated - group, 18 animals were subjected to the peritoneal injection of lidocaine (1. 5mg/kg) once a day. All animals were sacrificed and spinal cord removed for analysis after 6 ~8hours,3days,7days respectively. The MPO method was taken to testify the number of leucocytes of contused spinal cord and SOD method was taken to testify the products of free radical reaction. In the same time, the functional sores were recorded, then all the data were analysis by SPSS.Results1. The MPO value of treated - group is lower than that of control - group in each time point which is verified by t test. That is , there is more obvious leuco-cytic inflammation in control group than in lidocaine - treated group.2. The SOD value of treated - group is higher than that of control - group in each time point which is verified by t test. That is , there is less products of free radical reaction in the treated -group.3. Functional scores of rats in treated group is higher than contol group and it is testified by t test. That is, the function of treated - group is recovered better.4. Through correlational test, MPO value is not related with SOD value and MPO value is related significantly with functional score in each group.Conclusion1. We discovered that lidocaine can inhibit the delivery of leukocyte to the contused spinal cord tissues , and the function of lidocaine has linear correlation with functional score. We testify the protect function of lidocain in the secondinjury of ASCI.2. Lidocaine can inhibit the free radical reaction after ASCI.3. The function of preventing leucocytic inflammation has no relationship with the function of preventing free radical reaction, so the two functions of lido-caine are acting repeclively.