The Experimental Study To Promote Nerve Regeneration By Joint Use Between CNTF And IGF In Rats

1 Objective:The purpose of this study is locally use exogenous nerve growth factor ciliary neurotrophic factor (CNTF), insulin-like growth factor (IGF) and joint use of them, comparing the function of Peripheral nerve regeneration after injury each other,to find a better way to promote nerve regeneration .2 Method : A total of 48 wistar rats were randomly divided into four groups that group A IGF + CNTF, Group B IGF, Group C CNTF, group D blank control group. We established a model of sciatic nerve injury and a small room for nerver regeneration, and injected different drugs into the small room ,group A IGF + CNTF + chitosan , group B IGF + chitosan , group C CNTF + chitosan and group D chitosan + saline. Then after established model we measured and observed the sciatic nerve index (SFI) in 2, 4, 6, 8 weeks, taking Speed and amplitude of operated side sciatic nerve action potential in 4, 8 weeks , and finally killed all of the rats after 8 weeks taking out of regenerated nerve in small room for histological observed (light microscopy, electron microscopy). Using image analysis software Image-proplus to measure the average diameter of axons, the number of regenerated axons and the percentage area ratio in per unit area. All the results of the observation target was analyzed the main effect of IGF and CNTF and interactive effects by variance analysis of factorial design, IGF group and CNTF group was analyzed by two sample t-test, the test Standard isα= 0.05.3 Results1 Sciatic nerve index (SFI) :the variance analysis of factorial design for SFI proved that IGF and CNTF main effects and interactions were both significant, P<0.05,Combined with the mean comparative, that there is synergy between the two. IGF group compared with CNTF group by Two sample t- test, in 2,4 weeks with no significant difference between them,P>0.05, but in 6,8 weeks there was significant difference between the two, P<0.05,that is CNTF was superior to IGF,Combined with the mean comparative.2 Speed and amplitude of action potential:the variance analysis of factorial design for Speed and amplitude of Action potential proved that IGF and CNTF main effects and interactions were both significant,P<0.05, Combined with the mean comparative that there is synergy between the two. IGF group compared with CNTF group by Two sample t- test, in 4 weeks with no significant difference between them,P>0.05, but in 8 weeks there was significant difference between the two, P<0.05,that is CNTF was superior to IGF,Combined with the mean comparative.3 Histological observation: we found that all chitosan in the small room was absorbed and regenerated nerve of each group all growed across the nerve chamber. Under optical microscope the group A nerve fibers of arrangement and thickness is better than group B,C,D ,group B,C than the group D. There was no significant difference between groups B and C. Under Electron microscopy, the group A axon of swelling Degree , lamellar structure Condition and shape Condition are better than group B,C,D, group B,C was better than group D, There was no significant difference between B and C. the variance analysis of factorial design for average diameter of axons, the number of regenerated axons and the percentage area ratio of axons per unit area proved that IGF and CNTF had significant main effect and interaction effect,P<0.05, Combined with the mean comparative that there is synergy between the two. It had been proved that there was no distinct difference by Two sample t- test between group IGF and CNTF, Combined with the mean comparative P>0.05.4 Conclusion1 locally use exogenous nerve growth factor(IGF) ciliary neurotrophic factor(CNTF) can promote the nerve regeneration.2Insulin-like growth factor (IGF) and ciliary neurotrophic factor (CNTF) has synergistic effect.3For Insulin-like growth factor (IGF) and ciliary neurotrophic factor (CNTF) , there is no significant difference between the effect to promote t nerve growth in early period .