Biogênese mitocondrial e marcadores de estresse oxidativo em ratos treinados e suplementados com L-Arginina

• Ano de defesa: 2014
• Autor(a) principal: Silva, Carmem Peres Valgas da [UNESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Nutrition; Nutrição; Vida - Origem; Antioxidantes; Enzimas; Mitocondria; Stress oxidativo; Arginina
• Link de acesso: http://hdl.handle.net/11449/108755

The mitochondrion is an organelle which plays an important role in energy metabolism. It is known that both nitric oxide and exercise alone promote mitochondrial biogenesis, increasing its key transcription cofactors, among these, the peroxisome proliferator-activated receptor- coactivator (PGC)-1 (PGC-1α) and mitochondrial transcription factor A (mtTFA). However no study has evaluated the association L-arginine and exercise on mitochondrial biomarkers. The objectives of this study were to assess exercise tolerance, the redox state and mitochondrial biomarkers in trained rats supplemented with L-arginine. Methods: Wistar rats were divided into four groups: sedentary without and with L-arginine (SD; SDLA) and trained groups: with and without supplementation (TR; TRLA). Aerobic exercise was conducted in sessions of 60 min. 5 days a week for 8 weeks. L-arginine was administered orally by gavage (62.5 mg / ml / day / rat). Test of exercise tolerance with incremental speed until exhaustion was performed in the 8th week of physical training. The gastrocnemius muscle was isolated and protein expressions of mtTFA, ATP synthase subunit c, cytocrome c oxidase (COXIV), AMP-activated protein kinase (AMPK), the superoxide dismutase subtypes: Cu/Zn-SOD and Mn-SOD and neuronal nitric oxide synthase and endothelial (eNOS and nNOS) were measured in the cytoplasm and extract enriched in mitochondria by Western Blott. Fasting glucose, lipid profile, nitrite and nitrate (NOx) and MDA were also analyzed. Results: Physical training with or without L-arginine caused a reduction in blood glucose levels (approximately 8%) and plasma triglycerides (approximately 39%). While supplemented with L-arg. led to a reduction in total cholesterol (15%) compared to the SD and TR group. A significant increase in exercise tolerance in the last test in the trained animals (TR: 175% e TRLA: 229%) compared with sedentary groups. While the TRLA group presented enhanced exercise...