Experimental Study On Nerve Regeneration And Recovery In Repairing The Non-fresh Injury Of The Rat Sciatic Nerve Through Co-application Of Ngf And Gm₁

Objective 1.To explore the feasibility of repairing the non-fresh injury by using the xenogeneic acellular nerve scaffold graft.2.To study the effect of the co-application of NGF and GM1 on nerve regeneration and recovery after repairing the non-fresh injury by using the xenogeneic acellular.Methods 24 healthy adult Sprague-Dawley rats were randomly divided into 2 groups: the experimental group and the normal saline control group. Right sciatic nerve of adult SD rat was transected at the mid-thigh level to form a defective model (10mm) .After two weeks, the rats were repaired by xenogeneic acellular nerve scaffold graft that have been dipped in NS,NGF and GM1 solution respectively. After the second operation, the rats were injected with 0.1 ml of NS, NGF and GM1 solution respectively once a day for two weeks. The rats survived for 8W and 14W respectively with a group of 6 rats living in each time span. General observation was taken in each group the eighth and fourteenth week after the second operation. A series of measurement such as the recovery rate of the motor nerve conduction velocities (MNCV%) , the compound muscular action potential (CMAP%) in the hind limbs ,horseradish peroxidase (HRP) retrograde trace, the recovery rate of wet weight of triceps surae muscle and mean cross sectional area of gastrocnemius were utilized to evaluate the nerve repair effects during the experiment. Such activities were also carried out in this period as grafting part and its proximal and distal parts as well as stoma nerve fibers of the proximal part and distal part were taken histomorphologic observation and fluorescence immunohistochemical staining for the presence of nerve fibers S-100 and NF. Results In the same time span, the recovery rate of the motor nerve conduction velocities (MNCV%) , the compound muscular action potential (CMAP%) in the hind limbs, L3～L5 the dorsal root ganglion, the recovery rate of wet weight of triceps and mean cross sectional area of gastrocnemius in the experimental group were superior to those in normal saline group (P﹤0.05) . Through morphological observation we found that nerve grafts were in normal size with considerable blood vessels growing around and the nerve slightly connected to peripheral tissue. The regenerated nerve fibers arranged more densely and orderly, Schwann cells proliferated in larger quantity in grafting part.Conclusions 1 .Xenogeneic acellular nerve scaffold can successfully repairs the non-fresh injury in peripheral nerve. 2. Co-application of NGF and GM1 enhances peripheral nerve regenerate and recovery after repairing the non-fresh injury with xenogeneic acellular nerve scaffold.