Abstract

It has been shown that nitric oxide(NO) is a mediator of nerve injury or the physiological response to injury. The present study was conducted to determine whether NO synthase(NOS) inhibitor enhances functional recovery after nerve injury or not. Under pentobarbital anesthesia, male Sprague-Dawley rats were subjected to one of four different types of sciatic nerve injury (crush, cut, ligation, and sham injury models). The rats received i.p. injections of N^ω-nitro- L-arginine methyl ester(L-NAME), a NOS inhibitor, for ten days from the day of surgery. Twenty five days after injury, the rats were anaesthetized with urethane and the compound muscle action potentials(CMAPs) were recorded following sciatic nerve stimulation. L-NAME significantly shortened the latencies of the CMAPs in crush injury model compared to the vehicle treated rats. In the case of cut or ligation injury model, L-NAME tended to shorten the latencies but the differences between L-NAME and vehicle treated rats were not statistically significant. These results suggest that L-NAME facilitates functional recovery after sciatic nerve injury.