Neuregulins 1-alpha e 1-beta on the regeneration the sciatic nerves of (C57BL/6J) isogenic mice using the tubulization technique

OBJETIVO: avaliar o efeito das neuregulinas 1-alfa e 1-beta na regeneração de nervos ciáticos de camundongos C57BL/6J, adultos, machos, através da técnica de tubulização. MÉTODOS: Utilizaram-se 18 animais, divididos em 3 grupos, implantando-se prótese de polietileno em falhas de 4,0 mm no nervo ciático esquerdo: grupo 1 contendo apenas colágeno purificado (Vitrogen®); grupo 2, colágeno associado a neuregulina 1-alfa; grupo 3 com colágeno e neuregulina 1-beta. O grupo controle foi formado por 6 segmentos de nervos ciáticos direitos. Após 4 semanas, os animais foram sacrificados; extraiu-se segmento do ponto médio do nervo regenerado no interior das próteses, padronizaram-se cortes histológicos e confecção das lâminas para análise histomorfométrica. Confrontaram-se os resultados estatisticamente. RESULTADOS: Os animais tratados com neuregulinas tiveram maior número de axônios mielinizados, com diferença estatisticamente significante quando comparados ao grupo colágeno. Não houve diferença estatística entre os grupos de neuregulinas 1-alfa e 1-beta. CONCLUSÃO: a adição de neuregulinas proporcionou aumento significativo do número de fibras mielinizadas.PURPOSE: To evaluate the effect of neuregulins 1-alpha and 1-beta on the regeneration the sciatic nerves of male adult C57BL/6J mice, using the tubulization technique. METHODS: Eighteen animals were used, divided into three groups. A polyethylene prosthesis was implanted in a 4.0 mm defect of the left sciatic nerve, as follows: group 1 containing only purified collagen (Vitrogen®); group 2, collagen with neuregulin 1-alpha; group 3, collagen with neuregulin 1-beta. The control group was formed by six segments of right sciatic nerves. Four weeks later, the animals were sacrificed. A segment from the midpoint of the nerve regenerated inside the prostheses was extracted, histological sections were standardized and slides were made up for histomorphometric analysis. The results were statistically compared using the Tukey multiple comparisons test and Students t test. RESULTS: The animals treated with neuregulins had greater numbers of myelinized axons, with a statistically significant difference in relation to the collagen-only group. There was no statistical difference between the neuregulin 1-alpha and 1- beta groups. CONCLUSION: It was concluded that the addition of neuregulins provided a significant increase in the number of myelinized fibers