MATERIAL and METHODS: Thirty-two adult male rats were equally randomized to Sham, Control, U100, and U500 groups. Sham rats received a sham operation by exposing the right sciatic nerve without transection, while those in the Control, U100, and U500 groups underwent right sciatic nerve transection followed by immediate primary anostomosis. Sham and Control groups received saline (0.9% NaCl) injections intraperitoneally (i.p.), while U100 and U500 groups received 100 mg/kg and 500 mg/kg uridine injections (i.p.), respectively, once a day for 7 days after the surgery. Rats in all the groups were sacrificed on the eighth day; sciatic nerve samples were analyzed for apoptosis by Western Blotting and for oxidation parameters including myeloperoxidase (MPO), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) by Enzyme-Linked Immunosorbent Assay (ELISA).

RESULTS: Uridine treatment at the dose of 500 mg/kg significantly decreased as apoptosis determined by Caspase-3/Actin ratio and exhibited significant anti-oxidant effects as determined by decreased levels of MPO and MDA as well as increased levels of SOD, GPx, and CAT compared to controls. Uridine at 100 mg/kg was only found to decrease the Caspase-3/Actin ratio, although it significantly decreased MDA and increased CAT levels compared to controls.

CONCLUSION: Treatment with uridine reduces apoptosis and oxidation in a rat model of sciatic nerve injury dose-dependently. Thus, uridine may be beneficial in peripheral nerve regeneration by exhibiting anti-apoptotic and anti-oxidant effects. Keywords : Peripheral nerve injury, Sciatic nerve, Uridine, Apoptosis, Anti-oxidant, Rat