Morphological and molecular features in skeletal muscle (fibers and extracellular matrix), in pacus with ascorbic acid supplementation: in vivo and in vitro studies

Abstract

The skeletal muscle is responsible for locomotion and protein reserve in several organisms. The environment which the animal lives impacts directly in morphological and molecular features of this tissue. Fasting periods are common in fishes, in natural environment, as in captivity, and the nutrients restriction, besides being responsible for muscle degradation, promotes the excessive reactive oxygen species (ROS) production. As an alternative to minimize the effects of this process, compounds that act as antioxidants can be supplemented in the diet. Thus, the ascorbic acid (AA) is a compound that assists in ROS neutralization and, as observed on in vitro studies, can act in muscle growth. Considering this, the aim of this study is to evaluate the AA in signaling pathways and extracellular matrix in skeletal muscle of pacus after fasting and refeeding periods, in vivo and in vitro studies. Pacus juvenile (20g) were divided on groups: Control (continuous feeding - 200 mg/kg AA), Fasting (fishes subjected to 15 days of fasting) and refeeding for 15 days after the fasting period, applying different levels of AA, Standard (200 mg/kg AA) and Supplemented (400 mg/kg de AA). Our preliminary results show beneficial effects of AA supplementation in muscle growth. To achieve a deeper understanding of this effects, it will be evaluated the expression of genes related to mitochondrial biogenesis, extracellular matrix (ECM) compounds, synthesis and degradation processes, besides analysis of the skeletal muscle ECM morphological parameters. Also, in vitro analyses will be conducted to evaluate the direct effects of AA on muscle cells.