LLLT actives MMP-2 and increases muscle mechanical resistance after nerve sciatic rat regeneration

Author(s)

Carvalho Andraus, Rodrigo Antonio ; Maia, Luciana Prado ; de Souza Lino, Anderson Diogo ; Parron Fernandes, Karen Barron ; de Matos Gomes, Marcos Vinicius ; de Jesus Guirro, Rinaldo Roberto ; Barbieri, Claudio Henrique

• Document type: Journal article
• Source: Lasers in Medical Science; v. 32, n. 4, p. 771-778, MAY 2017.
• Web of Science Citations: 2

Abstract

The purpose of this study was to analyze the lowlevel laser therapy (LLLT) on metalloproteinase expression and the mechanical strength of skeletal muscle regeneration after peripheral nerve injury. Rats were subjected to crush injury of the right sciatic nerve, followed by LLLT (830 nm, 35, 70, 140, and 280 J/cm(2)) for 21 consecutive days. Functional gait analysis was performed at weekly intervals and the animals were sacrificed after the last evaluation at day 21 for collection of the gastrocnemius muscles, which were submitted to analysis of resistance, and the tibialis anterior, for evaluation of metalloproteinase-2 (MMP-2). The results were statistically analyzed at a significance level of 5%. The irradiated groups showed a significant decrease in the sciatic functional index and a significant increase in the mechanical strength when compared to the injured group with no treatment (p < 0.05), with no significant difference among the energy densities used. While no difference among groups was observed for the activity of MMP-2 in pro-active band, at the intermediate band, the activity was significantly higher (p < 0.05) for the groups irradiated with 35, 70, and 140 J/ cm2, and at the active band, the activity was significantly more intense in the group irradiated with 280 J/cm(2). The present study demonstrated that injury of the sciatic nerve, with consequent muscle denervation, are benefited by the laser therapy, which restores neuromuscular function, active MMP-2 and increases the maximum breaking strength. (AU)

• FAPESP's process: 11/09069-8 - Study of the dose-dependence of the laser of low power, in the regeneration of sciatic nerve of rats after injury for crushing
• Grantee: Rodrigo Antonio Carvalho Andraus
• Support Opportunities: Scholarships in Brazil - Doctorate