The effects of carnosine on SERCA activity

• Grant number: 16/18901-2
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: December 01, 2016
• End date: March 31, 2017
• Field of knowledge: Health Sciences - Physical Education
• Principal Investigator: Hamilton Augusto Roschel da Silva
• Grantee: Diogo Bassinello Bonoli do Carmo
• Supervisor: Craig Sale
• Host Institution: Escola de Educação Física e Esporte (EEFE). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Nottingham Trent University, England
• Associated to the scholarship: 15/23072-2 - Effects of b-alanine supplementation on strength performance, BP.IC

Abstract

Carnosine is cytoplasmic dipeptide abundantly found in the skeletal muscle. Obtained from the diet, carnosine is not directly absorbed by the skeletal muscle as it is rapidly hydrolyzed into its constituent amino acids, beta-alanine and histidine. Importantly, beta-alanine availability has been demonstrated to be the rate-limiting factor for muscle carnosine synthesis. Hence, beta-alanine supplementation effectively increases muscle carnosine concentrations. Carnosine may play several physiological roles; however, its action as an intracellular buffer has been argued as incontestable. As such, an increased muscle carnosine content via beta-alanine supplementation has been shown to improve high-intensity intermittent exercise performance. Additionally, recent studies have demonstrated that carnosine may also act as an intracellular calcium metabolism regulator, enhancing its release from the sarcoplasmic reticulum and/or its sensitivity at the contractile apparatus, helping to explain a possible effect of beta-alanine supplementation on strength performance. In this respect, the main aim of the present investigation is to evaluate the effects of carnosine treatment on sarcoplasmic reticulum Ca2+-ATPase (SERCA) pump activity. For this purpose, rat muscle samples will be obtained and analyzed in-vitro, after carnosine treatment for: 1) SERCA pump activity by calorimetric and spectrophotometric assays; 2) calcium uptake by fluorescence assay; 3) free amino acids concentration by high-performance liquid chromatography and; 4) protein content within each subcellular fraction, which will be quantified by BCA colorimetric assay. Data will be analyzed using a mixed-model for repeated measures procedure, and a Tukey post-hoc test will be employed for multiple comparisons (p < 0.05). (AU)