title: Cardiac ACE2/angiotensin 1-7/Mas receptor axis is activated in thyroid hormone-induced cardiac hypertrophy.
abstract: OBJECTIVE
  Thyroid hormone (TH) promotes marked effects on the cardiovascular system, including the development of cardiac hypertrophy. Some studies have demonstrated that the renin-angiotensin system (RAS) is a key mediator of the cardiac growth in response to elevated TH levels. Although some of the main RAS components are changed in cardiac tissue on hyperthyroid state, the potential modulation of the counter regulatory components of the RAS, such as angiotensin-converting enzyme type 2 (ACE2), angiotensin 1-7 (Ang 1-7) levels and Mas receptor induced by hyperthyroidism is unknown. The aim of this study was to investigate the effect of hyperthyroidism on cardiac Ang 1-7, ACE2 and Mas receptor levels.
  
  
  METHODS
  Hyperthyroidism was induced in Wistar rats by daily intraperitoneal injections of T4 for 14 days.
  
  
  RESULTS
  Although plasma Ang 1-7 levels were unchanged by hyperthyroidism, cardiac Ang 1-7 levels were increased in TH-induced cardiac hypertrophy. ACE2 enzymatic activity was significantly increased in hearts from hyperthyroid animals, which may be contributing to the higher Ang 1-7 levels observed in the T4 group. Furthermore, elevated cardiac levels of Ang 1-7 levels were accompanied by increased Mas receptor protein levels.
  
  
  CONCLUSIONS
  The counter-regulatory components of the RAS are activated in hyperthyroidism and may be contributing to modulate the cardiac hypertrophy in response to TH.
authors.affiliation: Department of Anatomy, Laboratory of Cell Biology and Functional Anatomy, University of São Paulo, Sao Paulo, Brazil.
authors.forename: Gabriela P
authors.initials: GP
authors.lastname: Diniz
authors.affiliation: Department of Anatomy, Laboratory of Cell Biology and Functional Anatomy, University of São Paulo, Sao Paulo, Brazil.
authors.forename: Nathalia
authors.initials: N
authors.lastname: Senger
authors.affiliation: Human and Natural Sciences Center, Federal University of ABC, São Paulo, Brazil.
authors.forename: Marcela S
authors.initials: MS
authors.lastname: Carneiro-Ramos
authors.affiliation: Department of Physiology and Biophysics, Biological Sciences Institute, Federal University of Minas Gerais, Belo Horizonte, BrazilCardiology Institute of Rio Grande do Sul, University Foundation of Cardiology.
authors.forename: Robson A S
authors.initials: RA
authors.lastname: Santos
authors.affiliation: Laboratory of Cellular Biology and Functional Anatomy, Department of Anatomy, Biomedical Sciences Institute, University of São Paulo, Av. Prof. Lineu Prestes 2415, Cidade Universitária, São Paulo, SP 05508-900, Brazil mchaves@usp.br.
authors.forename: Maria Luiza M
authors.initials: ML
authors.lastname: Barreto-Chaves
mesh_terms: D000803:Angiotensin I / Q000032:analysis* / Q000502:physiology; D000085962:Angiotensin-Converting Enzyme 2; D000818:Animals; D006332:Cardiomegaly / Q000209:etiology*; D006980:Hyperthyroidism / Q000150:complications*; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D010446:Peptide Fragments / Q000032:analysis* / Q000502:physiology; D007703:Peptidyl-Dipeptidase A / Q000032:analysis* / Q000502:physiology; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000032:analysis* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D043562:Receptors, G-Protein-Coupled / Q000032:analysis* / Q000502:physiology; D012084:Renin-Angiotensin System / Q000502:physiology
chemical_list: D010446:Peptide Fragments; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D043562:Receptors, G-Protein-Coupled; D000803:Angiotensin I; D007703:Peptidyl-Dipeptidase A; C000705307:ACE2 protein, human; C000705329:Ace2 protein, rat; D000085962:Angiotensin-Converting Enzyme 2; C118790:angiotensin I (1-7)
keywords: Mas receptor; angiotensin 1–7; angiotensin-converting enzyme type 2; thyroid hormone