Effect of different doses and application intervals of low-level laser therapy (660 nm) in cytochrome c-oxidase activity in different types of muscle fibers of skeletal muscle in rats

• Grant number: 11/21149-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2012
• End date: February 28, 2013
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Ernesto Cesar Pinto Leal Junior
• Grantee: Claudia Oliveira Caires
• Host Institution: Universidade Nove de Julho (UNINOVE). Campus Vergueiro. São Paulo , SP, Brazil

Abstract

Across the year's modulation of cytochrome, c-oxidase has been pointed to as a key mechanism in the interaction between LASER radiation with different biological tissues. More recently, a study demonstrated that cytochrome c-oxidase activity is increased by phototherapy in different types of skeletal muscle fibers of rats. Recent studies of our research group with phototherapy have shown positive results in delaying skeletal muscle fatigue and improving the status of biochemical markers related to skeletal muscle recovery when these therapies were applied before exercise. We think that cytochrome c-oxidase activity can play a key role in low-level laser therapy (LLLT) effects in delaying skeletal muscle fatigue. With these perspectives in mind, this research project aims to evaluate the effects of different LLLT doses in cytochrome c-oxidase activity in different types of skeletal muscle fibers, as well as to determine the time interval that occurs at peak of activity of cytochrome c-oxidase in different types of skeletal muscle fibers. For such, we will perform an animal experiment. In this experiment tibialis, anterior muscle of rats will be irradiated with different LLLT doses (1, 3, and 10 J), 660 nm wavelength, with 50 mW power output. After irradiation muscles will be removed at different experimental times (5, 10, 30 minutes, 1, 2, 12, and 24 hours) and stored for further analysis. Analysis of cytochrome c-oxidase activity in different types of muscular fiber will be performed through immunohistochemical analysis, analysis of histological images, and Western Blotting.(AU)