MATERIAL and METHODS: Male Sprague-Dawley rats were randomized to receive sham surgery plus saline (Sham group), right sciatic nerve transection and primary repair plus saline (Control group), right sciatic nerve transection, and primary repair plus 500 mg/kg uridine (Uridine group). Saline or uridine was injected intraperitoneally (i.p.) for seven days, and the rats were monitored for 12 weeks after surgery. We evaluated electrophysiological and functional recovery using electromyography (EMG) and sciatic functional index (SFI) at six and 12 weeks, respectively. At 12 weeks, rats were decapitated and their right sciatic nerves were examined in macroscopic and histomorphologic manners.

RESULTS: Functional evaluation by SFI and sciatic nerve conduction velocity analyzed by EMG both decreased in the Control group but recovered in the Uridine group 12 weeks after surgery. Additionally, upon experiment completion, Uridine treatment was observed to enhance nerve adherence, separability scores, and the number of myelinated axons.

CONCLUSION: These results reveal that short-term Uridine treatment provides morphological and electrophysiological benefits, which are represented by long-term functional improvement in a rat model of sciatic nerve injury. These findings validate and extend our knowledge on Uridine?s regenerative effects in peripheral nerve injuries. Keywords : Electrophysiology, Peripheral nerve regeneration, Sciatic functional index, Sciatic nerve injury, Uridine, Rat