Objective
To determine the effect of functional electrical stimulation (FES) in the paralyzed muscles of rabbits with spinal cord injury (SCI). Method: Fifteen male New Zealand white rabbits were injured by spinal cord transection at the T6 level. We classified animals into a normal control group (n=3), and SCI without FES (n=3), SCI with 10 Hz FES (n=6) and SCI with 40 Hz FES (n=6) groups. FES was applied on both tibialis anterior (TA) muscles at two frequencies (10 Hz, 40 Hz) for 1 hour daily for 2 weeks. After treatment TA muscles were separated and apoptotic features were measured by in situ DNA nick-end labeling (TUNEL), DNA fragmentation assays and western blotting for Bcl-2 and Bax protein. Results: In TUNEL and DNA fragmentation assay results, the FES groups showed more fragmented myonuclei and DNA, and western blotting showed more Bax protein expression in FES groups than no FES group and control (higher in 40Hz group), whereas Bcl-2 protein expressions were similar in all groups. Conclusion: Apoptosis of paralyzed muscle was increased in FES group with higher Bax/Bcl-2 in 40 Hz than in 10 Hz. To evaluate the clinical significance of muscle apoptosis with FES in SCI, further study would be needed. (J Korean Acad Rehab Med 2007; 31: 85-91)