Analyses of the neuromuscular junctions and associated proteins with focus on morphofunctional recovery: a comparative use of fibrin sealant and suture.

Abstract

Peripheral nerves are often affected by injuries that lead to nerve impulse interruption. Functional recovery is usually late and considered a challenge for medical practice. Thus, we suggest that this type of response is associated with failures in the reinnervation of the neuromuscular junction (NMJ), accompanied by alterations in its structural proteins, causing a defect in the muscular eletric activation capacity. This project aims to compare the use of fibrin sealant and suture after sciatic nerve injury with focus on the NMJ and associated proteins. Fifty adult male Wistar rats will be used, divided into five experimental groups: Control-Sham (CS) and Control-dennervated (CD); Suture Injury (SI); Fibrin Sealant Injury (FI) and Suture Injury + Fibrin Sealant (FSI). The animals (preoperative) of CS will be submitted to a superficial incision of the skin after the catwalk anlysis. The right sciatic nerve neurotmesis will be performed in the CD, SI, FI and FSI groups.It will be associated with proximal and distal stump fixation in the adjacent muscles. After 7 days it will be done the reconnection of the stumps with fibrin sealant (CEVAP) in the FI and with suture in the SI and both procedures in the FSI. At 15, 30 and 60 days the animals will undergo a catwalk test again and they will be euthanized at the end of the experiment (60 days). The right ischiatic nerves will be removed and analyzed for morphologic and morphometric parameters. The right soleus muscles will be processed to analyse NMJ morphology, ultrastructure and morphometry; nAChRs morphometry and nerve terminals morphology by confocal microscopy; morphology and morphometry of muscle fibers (HE), I and II fibers types frequency, and Protein quantification of nAChRs, Agrina, Musk MMP3 and Schwann cells. (AU)