Effect of the association between the low-level laser and the purified protein from natural latex (Hevea brasiliensis) on the crush injured sciatic nerve in wistar rats: functional, sensorial, morphometric and ultrastructural study

Abstract

The treatment of lesions that affect peripheral nerves is still a medical challenge and non-surgical procedures have added in their therapeutics. In this context the low level laser-therapy (LLLT) and the natural latex protein (Hevea brasiliensis, F1 protein) have shown positive effects. The aim of this study is to analyze the effects of the LLLT associated with F1 protein in crush injuries of the sciatic nerve (15 kgf, 5.2 MPa, 10') in rats, by means of morphologic, morphometric, sensorial and functional approaches. Male Wistar rats (200 - 250g) will be divided into 6 groups (n = 24 per group) : CG - control; EG - exposed nerve; GLe - untreated injured nerve; GL - injured nerve irradiated with LLLT ( 15J/cm2, 780nm) ; GF1 - injured nerve with the application of F1 (0.1 %); and GL & F1 - injured nerve that will receive the F1 protein (0.1 %) associated with LLLT (15J/cm2, 780nm). After 1, 8, 14, 28, 56 and 180 days after nerve injury the sensorial and functional analyzes will be performed using the following techniques: 1. Von Frey monofilaments 2. Paw pressure test 3. Test grip strength test and 4. Gait analysis. After 2, 15, 57 and 181 days of nerve injury, the animals of each subgroup (n = 6) will be anesthetized and euthanized by cardiac perfusion (2.5% glutaraldehyde in sodium cacodylate buffer 0.1M, pH 7.2).Right and left sciatic nerves will be processed and analyzed by light and transmission electron microscopy for the histological, morphometric and ultrastructural analysis of the proximal, middle (injury itself) and distal sciatic nerve segments. This project aims to contribute to the understanding of the functional and structural changes resulting from crush injuries of peripheral nerves and propose alternatives in the treatment of these types of lesions. (AU)