Effects of glycine on electrical and histological properties of a rat peripheral nerve injury model.

BACKGROUND: Treatment of peripheral nerve injuries focuses on lesion type, from expectant to interfascicular repair. Many experiments have been undertaken using different factors to facilitate better or faster nerve stump growth: nerve growth factor (NGF), plaque growth factor (PGF), hyaluronic acid, leukemic inhibiting factor, and GABA, etc. Glycine is an inhibitory neurotransmitter in the brain stem and spinal cord, and it also plays a critical role as a modulator of NMDA receptors. We studied the potential regenerative effect of glycine administered for different periods of time and compared results with a control group. METHODS: The sciatic nerve of Wistar rats was exposed and the electrophysiology procedure was performed: the nerve was cut transversally and stitched back in place with four isolated cardinal 9/0 nylon stitches on each end. Study group rats were administered glycine 40 mM/kg daily for 15, 30, and 60 days, while control group rats were medicated with isotonic saline solution 0.9% for the same time periods. At the end of each study time period, the electrophysiological study was repeated. Animals were sacrificed on the 15th, 30th and 60th postoperative day and the sciatic nerve was exposed and prepared for histological studies. RESULTS: According to our results, glycine was effective in the morphologic regeneration and functional recovery of the sciatic nerve post-injury in Wistar rats with one month administration. CONCLUSION: We observed that nerve histology with glycine administration was more similar to that of normal nerves.