The action of resistance exercise associated with low level laser therapy in knee osteoarthritis induced by transection of the anterior cruciate ligament in rats

• Grant number: 14/13704-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2014
• End date: August 31, 2016
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Ana Claudia Muniz Renno
• Grantee: Vitória dos Santos Claudino
• Host Institution: Instituto de Saúde e Sociedade (ISS). Universidade Federal de São Paulo (UNIFESP). Campus Baixada Santista. Santos , SP, Brazil

Abstract

Osteoarthritis (OA) is a degenerative joint disease, with a major knee. Exercise and low-level laser therapy (LLLT) are therapeutic strategies that help reduce the changes of articular cartilage resulting from OA knee, however the mechanisms activated by these resources remain uncertain. The objective of this study is to evaluate the effects of resistance exercise associated with LLLT on the articular cartilage of rats subjected to an experimental model of OA induced by section of the anterior cruciate ligament (ACLT). 30 Wistar rats, males, separated into 3 groups (n = 10) will be used: osteoarthritic (GO); osteoarthritic and resistance exercise (Goer); osteoarthritic resistance exercise and irradiated with LLLT (GOERL). A laser GaAlAs 3 times per week will be used in two points of the left hind paw (medial and lateral joint line). Treatments will begin four weeks after surgery. The resistance exercise protocol consist of jumps in liquid medium at 32 ° C: 4 sets of 10 jumps each, with intervals of 30 seconds between sets 3 days a week for 8 weeks, with loads ranging from 50-70% of body mass of the animal. A laser GaAlAs will be used (continuous; » = 808 nm, P = 50 mW, beam area = 0.028 cm2 , t = 28 s, D = 50 J/ cm2, E = 1.4 J; irradiance = 17.8 mW/ cm2 ), 3 times per week and / or after training sessions at 2 points of the left hind leg (medial and lateral joint line). To evaluate and compare the effects of training morphological and morphometric analyzes of cartilage (cellularity, thickness, density of chondrocytes and proteoglycan content) and protein expression of IL-1² will be held. It is expected that the results of this project will bring significant contribution in elucidating the mechanisms of action triggered by resistance exercise, thus optimizing their use in the rehabilitation of degenerative disorders. (AU)