Evaluation of the comparative effects of infrared and red laser photobiomodulation therapy on skeletal muscle atrophy in an immobilization model in rats

Introduction: Skeletal muscle atrophy leads to a reduction in muscle strength, functionality, and the quality of life of individuals. Objective: To explore the effects of two different wavelengths (red and infrared) of laser PBMT on muscle atrophy and its active ingredients on skeletal muscle atrophy using an in vivo model of muscle atrophy. Methods: Thirty-two Wistar rats were randomly divided into four experimental groups: control (CG) animals were not immobilized and did not receive any type of treatment; immobilized animals with no treatment (ImC); immobilized animals submitted to red laser with wavelength of 660 nm (ImR) and near-infrared laser with wavelength of 808 nm (ImIR) treatments. The treatments were applied daily, at 2 points in the right gastrocnemius muscle (cranial and caudal), through the punctual contact technique, for 9 sessions, with the first application immediately after removing the cast. Results: The histological results demonstrated that in both treated groups (red and infrared wavelengths) a reduction of the inflammatory infiltrate and less connective tissue thickening when compared to the ImC. However, only infrared light was observed regenerating muscle fibers and an increase in the number of oxidative fibers (type I). Conclusion: These results suggest that red and infrared wavelength laser PBMT were able to promote changes in the morphology of the gastrocnemius muscle submitted to atrophy in an experimental immobilization model, reducing the inflammatory infiltrate and the formation of intramuscular connective tissue. However, infrared laser PBMT promoted more evident positive effects by increasing regenerating muscle fibers and the number of oxidative fibers.

Fibrin biopolymer sealant and aquatic exercise association for calcaneal tendon repair

ABSTRACT Purpose The aim of this work was to analyze the effect of fibrin biopolymer sealant (FS) associated or not to aquatic exercise (AE) on the calcaneal tendon repair. Methods Forty-four female Wistar rats were randomly divided into four experimental groups: Lesion control (L), Lesion and FS (LS), Lesion and AE (LE) and Lesion and FS associated to AE (LSE). The edema volume (EV), collagen ratio, and histopathological analysis were evaluated after 7, 14, and 21 days of partial tendon transection. Results The EV was statistically reduced for all treatment groups after 7 and 21 days when compared to L group. The LS and LSE had the highest EV reduction after 21 days of treatment. The FS group didn't induce tissue necrosis or infections on the histopathological analysis. It was observed tenocytes proliferation, granulation tissue and collagen formation in the tendon partial transection area in the FS group. The LSE demonstrated higher amount of granulation tissue and increased the collagen deposition at the injury site. Conclusions Our data suggests that the therapeutic potential of the association of heterologous fibrin biopolymer sealant with aquatic exercise program should be further explored as it may stimulate the regeneration phase and optimize calcaneal tendon recovery.

Verification of the Effects of Red Light-emitting Diode Therapy on Acute Lung Injury in a Sepsis Model in Rats

Abstract The aim of this study was to evaluate the in vivo response of red light-emitting diode (LED) on acute lung injury (ALI) in a sepsis model in rats. Twenty rats were randomly allocated into two experimental groups (n=10): Control Sepsis Group (CS); sepsis and red LED group (SRL). The anterior region of the trachea and ventral regions of the chest (below the ribs), bilaterally were irradiated daily for two consecutive days, starting immediately after the surgery using red (630 nm) LED. The histological results showed that in red LED treated group presented a modulation of the lung inflammatory process, less intense alveolar septum thickening and decrease of the inflammatory cells. Moreover, LED significantly reduced the lung injury score and increased interleukin type 10 (IL-10) protein expression compared SG. These results suggest that LED was efficient in attenuating ALI in a sepsis model in rats by reducing inflammatory cells into lung tissue and enhancing the anti-inflammatory cytokine production.