Experimental Study on Rat Sciatic Nerve Defect Repaired with Acellular Allograft Combined with Extracellular ATP
|School||Zunyi Medical College,|
|Keywords||acellular nerve scaffold nerve defect ATP muscle atrophy|
Objective:To investigate the comprehensive therapeutic effect of acellular allograft combined with extracellular ATP in repairing 10 mm sciatic nerve defect in rat, providing theory for the therapy of nerve gap in clinic.Methods:Using chemical method of TritonX-100 and sodium deoxycholate to eliminate Schwann cells, myelin sheaths and axons of male adult SD rats, obviate evoking a conspicuous rejection. Sixty-four SPF female rats were randomly divided into 4 groups. Excepting normal group (Group D), three groups were respectively set up the animal model of right sciatic nerve gap of 10mm and treated as follow:Group A, experimental group, defects of nerve were repaired with extracted allografts. Postoperatively, a dosage of ATP, as a target muscle injection was given once a day to each rat in this group. Group B, control group I, gaps of sciatic nerve were bridged with autografts. Group C, control groupⅡ, gaps were left. Evaluation of therapeutic effect included gait analysis, electrophysiological test, mean area and density of regenerated nerve axon by toluidine blue stain, ultrastructural, target muscle wet weight, MEP examination by AchE stain at postoperative 3 and 6 months.Results:Observation of functional regain:rats of groupA、B and C performed trophesy appearances postoperatively, Group C was obvious, Group A was similar to Group B. The function of Group A and B make a recovery partially, and are not better than that of Group D at 6 months after operation, although they are much better than themselves at 3 months postoperatively. There is no any functional recovery in Group C until 6 months after operation. The nerve of Group A、B and D resembled each other in shape, while Group C looked vacant. There is no significant difference in SFI and wet weight of gastrocnemius muscle between Group A and B at 3 and 6 months postoperatively, and they are significantly superior to that of Group C and inferior to that of Group D. Mean area of axon of Group A is superior to Group B, but the density of axon is opposite. There is no significant difference in density of axon between Group A and D. NCV in Group B is better than in Group A and worse than in Group D at 3 months, but at 6 months, there is no significant difference between Group A and B. There is no any evidence of nerve regeneration can be observed in Group C.Conclusion:The acellular allograft introduces the regeneration of axons, not be repulsed by the recipient after transplanted. Extracellular ATP delays the atrophy process of target muscle. The scaffold combined with extracellular ATP can be applied in the restoration of peripheral nerve defect alternatively. The effect of combination in repairing nerve gap would be more satisfied.