Ascorbic acid supplementation effects during refeeding in musculature of pacus subjected to a fasting period

Abstract

In fishes, skeletal muscle comprises the major part of corporal mass. Muscle phenotype and development involve the activation or inhibition of signaling pathways, responsible for controlling anabolic and catabolic activities. The balance between these pathways is modulated by extrinsic and intrinsic factors as food availability. Fasting, besides stimulating muscle degradation, leaves to a physiological stress and reactive oxygen species (ROS) production, harmful to organisms. Compounds that act as antioxidants can help in damage prevention that occurs in this situation and, possibly, assist in muscle growth resumption on appropriate conditions. The ascorbic acid (AA) in addition to act as antioxidant operates in others important reactions in living organisms and, recently, in vitro studies suggests its actuation on muscle development. Therefore, to evaluate parameters that correlate AA supplementation effects in fishes, as well as the investigation of a possible mechanism by which this can happen are important aiming minimize the negative effects of physiological stress condition on muscle growth. The aim of this work is to evaluate the effects of refeeding with ascorbic acid supplementation and restriction after a fasting period in anabolism and catabolism of pacu juvenile's skeletal muscle. The parameters will be analyzed on groups Control (continuous feed with 200mg/kg of AA); Fasting (fasting period of 15 days) and three refeeding groups to 30 days after fasting: nutritional requirement (feed with 200mg/kg of AA), below requirement (feed with 100mg/kg of AA) and above requirement (feed with 400mg/kg of AA). Complementary analyses will be realized in myoblast cell culture of pacu to evaluate the direct effects of this protocol in muscle cells. The obtained data will be subject to appropriate statistical analyses. (AU)