Wirkung von rekombinantem Growth and Differentiation Factor 5 (rhGDF-5) auf die Regeneration nach peripherer Nervenschädigung im Rattenmodell

Introduction: Injuries of peripheral nerves are among the most common diagnosis at a center of hand, plastic and reconstructive surgery. Despite modern microsurgical suture techniques and/or primary reconstruction with autologous nerve transplantation the result is often unsatisfying. Goal of this study is, to determine the influence of rhGDF-5, a member of the Transforming Growth Factors (TGF-β) superfamily, on the ability of regeneration of the peripheral nerve system. RhGDF-5 is linked to have osteogenic as well as angio- and neurogenic properties. Material and Methods: In rats a sharp transection of the sciatic nerve was followed by reconstruction through a microsurgical epineural suture (group A and B), as well as the transplantation of a syngenic nerve graft after nerve resection (group C and D). In addition to the sutures fibrine-glue was used. In groups A and C rhGDF-5 was applied in the dosage of 2 µg. In groups A and B the period of examination was seven weeks, in groups C and D ten weeks. The degree of nerve regeneration was evaluated by functional tests such as the rotarod test, walking-track analysis and the electronic-von-Frey-test. Additionally the wet muscle weight was determined, the number of the damaged nerve fibers, and the thickness and amount of the regenerated axons and myelin sheaths were noted. Furthermore the g-ratio was determined. Results: Group C showed significant less damaged nerve fibers than control group D (p < 0.05). Between group A and B no significant difference was found. Groups A and C showed more regenerated nerve fibers than the corresponding control-groups. Between groups C and D a significant difference was found (p < 0.05). The tests of functional recovery showed no distinct predominance. Conclusion: In this study rhGDF-5 led to a histological and histomorphometrical improvement of peripheral nerve regeneration which could not be verified through clinical tests.