Effects of low-level laser on tibialis anterior muscle in induced sepsis model by cecal ligation and puncture

• Grant number: 13/25622-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): April 01, 2014
• Effective date (End): December 31, 2014
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Ana Claudia Muniz Renno
• Grantee: Aya Hoshikawa Hirai
• Host Institution: Instituto de Saúde e Sociedade (ISS). Universidade Federal de São Paulo (UNIFESP). Campus Baixada Santista. Santos , SP, Brazil

Abstract

Sepsis is the major cause of morbimortality in hospitalized patients and is defined as an infection with systemic manifestations. It leads to the release of large amounts of inflammatory mediators and the subsequent release of secondary mediators which further aggravates inflammation. One effect of sepsis is the inhibition of the synthesis of myofibrillar and sarcoplasmic proteins, preferably in muscles composed of fast twitch fibers resulting in decreased muscle strength. The low-level laser therapy (LLLT) is a complementary, noninvasive technique used for therapeutic purposes as safe and effective treatment for a number of pathological conditions. Studies show that LLLT reduces inflammatory cells and the enzymes responsible for the release of chemotactic factors at the initial stage of inflammation. It also inhibit the synthesis of prostaglandins and cytokines and increases levels of antioxidant enzymes in various models of inflammation. The objective of this study is to evaluate and describe the effects of treatment with LLLT on the inflammatory response and musculoskeletal changes in the model of chronic sepsis induced in rats by the technique of cecal ligation and puncture (CLP). 56 Wistar male rats (three months old and mean weight of 300 g) will compose seven groups: control (C), sepsis 24h (S24), sepsis 48h (S48), sepsis 72h (S72), sepsis 24 and LLLT (S24L), sepsis 48 and LLLT (S48L) and sepsis 72 and LLLT (S72L). Irradiation will start immediately after surgery in the following points: tibialis anterior, gastrocnemius and diaphragm bilaterally. Morphological and morphometric analysis of the tibialis anterior muscle and immunohistochemistry of muscle atrophy (Murf-1 and atrogina-1) will be made.