2. CHONDROITINASE ABC AND ACUTE ELECTRICAL STIMULATION ARE BENEFICIAL FOR MUSCLE REINNERVATION AFTER A SCIATIC NERVE TRANSECTION IN RAT

Abstract

Purpose: Nerve re-generation and functional recovery are often incomplete after a peripheral nerve lesion. The aim of this study was to determine if the injection of chondrotinase ABC at the lesion site, one hour of electrical stimulation, and the combination of these treatments at the time of repair are effective in promoting nerve regeneration and muscle re-innervation.

Method: A complete right sciatic nerve section was done on 32 female Sprague-Dawley rats. End-to-end microsuture repair was performed and fibrin glue was added. Five groups were studied:

1. Sutures and Fibrine glue (S+F),

2. S+F and chondrotinase ABC,

3. S+F and electrical stimulation,

4. S+F and chondrotinase and electrical stimulation,

5. uninjured nerve. Video kynematic, EMG, muscle strengh and axonal count were used to asses nerve recovery at 150 days post-repair.

Results: Side video kinematics was performed and a larger excursion of the hip-ankle-toe angle during walking was showed in groups 2, 3, and 4. (p< 0.05) At 150 days, in-vivo EMg activity and maximal muscle force were similar in group 2, 3, 4, 5 and all of them were higher compared to group 1 (p< 0.05). Histological study revealed equivalent number of axone in all group and pore correlation with nerve function.

Conclusion: In conclusion, five months after nerve transection, the recovery is incomplete when using suture and fibrine glue only. Moreover, an injection of chondrotinase ABC at the lesion site and/or one hour of electrical stimulation of the proximal nerve stump is beneficial in promoting nerve regeneration and functional muscle re-innervation.