Comparison of the effect of mexiletine and methylprednisolone on neural function and histopathological damage after transient spinal cord ischemia in rabbits.

AIM The purpose of this study was to investigate the effect of mexiletine on the neural function and histopathological changes after ischemic spinal cord injury in rabbits. We also compared the effect of mexiletine to that of methylprednisolone. MATERIAL AND METHODS Twenty six male New Zealand white rabbits were randomly divided into six groups. Group 1; sham operated group (n=3) underwent only the surgical exposure of infrarenal aorta. Group 2 (n=4) received neither intravenous (iv) nor intraperitoneal medication but the infrarenal aorta was cross-clamped. Group 3 (n=5) received intravenous infusion of 20 ml/kg/h normal saline. Group 4 (n=5) received 30 mg/kg intravenous methylprednisolone. Group 5 (n=3) received intraperitoneal 20mg/kg/h normal saline. Group 6 (n=6) received 50mg/kg mexiletine intraperitoneally. Temporary spinal cord ishemia was induced by infrarenal aortic occlusion for 25 minutes and followed by reperfusion. The neural status was scored using the Tarlov criteria at 24 hours after reperfusion. Immediately after the neurological scoring, the spinal cords of all animals were removed for histopathological study. RESULTS Histopathological examination scores were significantly higher in group 6 compared to group 2 (p < 0.05). CONCLUSION Mexiletine can significantly ameloriate the neural function and prevent histopathological damage after transient spinal cord ischemia in rabbits. This is the first research that investigates the neuron=protective effect of mexiletine in a spinal cord ischemia model.