CILIARY NEUROTROPHIC FACTOR ENHANCES PERIPHERAL-NERVE REGENERATION

Background: Adjunctive measures to enhance nerve repair have focused o n a variety of trophic factors that alter the physiologic response to nerve injury through Schwann cell-axonal interactions. Objective: To e valuate the effects of two trophic factors, ciliary neurotrophic facto r and nerve growth factor, on axonal response to injury. Design: A pro spective, randomized, blinded animal study with a placebo control usin g lactated Ringer's solution. Interventions: Rat sciatic nerves were t ransected and repaired as a model of injury following which experiment al factors were delivered in vivo through an implantable osmotic pump. Outcome Measures: Functional nerve recovery, muscle mass, and gene ex pression in the three experimental groups were evaluated. Results: The ciliary neurotrophic factor group (n=6) showed a higher sciatic funct ional recovery (P=.003) and preservation of affected muscle mass (P=.0 3) compared with the nerve growth factor (n=8) and control (n=8) group s. Molecular analysis of injured nerves showed no difference in expres sion of ciliary neurotrophic factor, myelin basic protein, or low-affi nity neurotrophin receptor messenger RNA among the three groups. Concl usion: These data suggest that ciliary neurotrophic factor may serve a s an important neurocytokine for axonal regrowth during peripheral ner ve regeneration.