Analysis of dose-response patterns of low-level laser therapy with different wavelengths in skeletal muscle fatigue in rats

• Grant number: 12/04295-2
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2013
• End date: December 31, 2013
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Ernesto Cesar Pinto Leal Junior
• Grantee: Larissa Aline Santos
• Host Institution: Universidade Nove de Julho (UNINOVE). Campus Vergueiro. São Paulo , SP, Brazil

Abstract

Skeletal muscle fatigue and recovery are novel areas of research in Low-Level Laser Therapy (LLLT). Recent studies of our research group with phototherapy have shown positive results delaying skeletal muscle fatigue and improving the status of biochemical markers related to skeletal muscle recovery when these therapies were applied before exercise. However, several factors still remain unknown such as: optimal doses and treatment parameters, mechanisms of action, effects in mild and long-term, and "therapeutic windows" that radiation with different wavelengths could have. With these factors in mind, the aims of this project are: to evaluate the effects of LLLT in skeletal muscle fatigue; to evaluate the effects of LLLT in muscular activity-induced skeletal muscle damage; and to identify dose-response patterns establishing the optimal doses of 660 nm, 830 nm and 905 nm LLLT previously to muscular activity. For such, we will perform an animal experiment. In this animal experiment we will employ a tetanic contractions protocol to induce skeletal muscle fatigue in tibialis anterior muscle of animals. Previously to protocol animals will be irradiated with 660 nm, 830 nm or 905 nm LLLT (both with 50 mW) at one of 3 different doses (1.0 J; 3.0 J; or 10.0 J). We will evaluate outcomes related to skeletal muscle performance (force peak, time to decay 50% of peak force, and muscular work), morphology of skeletal muscle (histology), and biochemical markers related to skeletal muscle damage (Creatine Kinase - CK).

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SANTOS, LARISSA ALINE; MARCOS, RODRIGO LABAT; TOMAZONI, SHAIANE SILVA; VANIN, ADRIANE AVER; ANTONIALLI, FERNANDA COLELLA; GRANDINETTI, VANESSA DOS SANTOS; ALBUQUERQUE-PONTES, GIANNA MOES; VICENTE DE PAIVA, PAULO ROBERTO; BRANDAO LOPES-MARTINS, RODRIGO ALVARO; CAMILLO DE CARVALHO, PAULO DE TARSO; et al. Effects of pre-irradiation of low-level laser therapy with different doses and wavelengths in skeletal muscle performance, fatigue, and skeletal muscle damage induced by tetanic contractions in rats. Lasers in Medical Science, v. 29, n. 5, p. 1617-1626, SEP 2014. (12/06832-5, 10/52404-0, 12/04295-2)