Effect of dexamethasone on preventing tibial nerve conduction velocity loss in tourniquet neuropathic rat

Introduction: Ischemic-reperfusion nerve injury has been suggested as the mechanism for post-tourniquet limb paralysis. Dexamethasone (Dex) has been known to prevent ischemic-reperfusion side effects in some tissues, we here evaluated its possible preventing effect on tourniquet induced nerve injury. Methods: 36 male Wistar rats (200-250 g) were divided randomly into 6 equal groups named as Sham Operated, Vehicle, Control and treatments (Dex1, Dex2 and Dex3). Tourniquet was applied to the right hind limb of all Animals except of Sham and Vehicle groups for 3 hours. Animals of Control and Vehicle groups were received 1 ml of vehicle (Normal saline containing 4% ethanol). Animals of Dex1, Dex2 and Dex3 groups were respectively received 1 mg/kg, 2 mg/kg and 3 mg/kg of Dex 30 min before fastening tourniquet, 30 min after releasing tourniquet and daily during the week of experiment. Motor nerve conduction velocity (MNCV) of tibial nerve in response to nerve stimulation was measured one week after releasing the tourniquet. Results: Application of the tourniquet for 3 h significantly decreased MNCV in all animals (p<0.001). Dexamethasone administration in doses of 2 and 3 mg/kg (Dex2 and Dex3 groups) resulted in a significant improvement of MNCV (p<0.001) in comparison to control group. Conclusion: These data indicated that dexamethasone administration in doses of 2mg/kg and 3mg/kg could prevent nerve conduction velocity loss in tourniquet neuropathic rat.