Role of adrenaline in the protein metabolism regulation in cardiac muscle of rats

• Grant number: 19/22446-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2020
• End date: February 28, 2021
• Field of knowledge: Biological Sciences - Biochemistry - Metabolism and Bioenergetics
• Principal Investigator: Isis Do Carmo Kettelhut
• Grantee: Leticia Andrade Costa
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 18/10089-2 - Neural, hormonal and nutritional control of autophagy, AP.TEM

Abstract

The mechanisms that control the cardiac muscle mass are extremely important for the proper functioning of the heart, and the sympathetic nervous system is one of the main regulators of this process. The maintenance of muscle mass is essentially performed by the balance between synthesis and protein degradation. Stimuli such as insulin and IGF-1 induce anabolic pathways activating AKT and mTOR, which promote protein synthesis and increase muscle mass. On the other hand, energy deficit situations lead to activation of catabolic pathways, which promote protein degradation in order to provide amino acids for glucose synthesis by gluconeogenesis to maintain blood glucose and normal cellular functioning. There are two major intracellular processes of protein breakdown, autophagy and the ubiquitin- proteasome systems. Several studies have shown the influence of the sympathetic nervous system (SNS) on the control of skeletal muscle mass. It has been observed that the activation of the SNS in vivo or catecholamines in vitro have an inhibitory tonus on the proteolytic pathways and a stimulatory effect on protein synthesis, protecting the skeletal muscle from excessive mass loss during, for example, food restriction. Since the maintenance of cardiacmass is essential for the normal functioning of the cardio-respiratory system, this project aims to investigate if adrenaline can also protect the heart muscle mass during catabolic situations such as fasting. (AU)