title: T3 and T4 decrease ROS levels and increase endothelial nitric oxide synthase expression in the myocardium of infarcted rats.
abstract: Myocardial infarction leads to a reduction in nitric oxide (NO) bioavailability and an increase in reactive oxygen species (ROS) levels. This scenario has been shown to be detrimental to the heart. Recent studies have shown that thyroid hormone (TH) administration presents positive effects after ischaemic injury. Based on this, the aim of this study was to evaluate the effect of TH on NO bioavailability as well as on endothelial nitric oxide synthase (eNOS) expression after myocardial infarction. Male Wistar rats were divided into three groups: Sham-operated (SHAM), infarcted (AMI) and infarcted + TH (AMIT). During 26 days, the AMIT group received T3 and T4 (2 and 8 µg/100 g/day, respectively) by gavage, while SHAM and AMI rats received saline. After this, the rats underwent echocardiographic analysis were sacrificed, and the left ventricle was collected for biochemical and molecular analysis.
  
  
  METHODS
  one-way ANOVA with Student-Newman-Keuls post test. AMI rats presented a 38% increase in ROS levels. TH administration prevented these alterations in AMIT rats. The AMIT group presented an increase in eNOS expression, in NOS activity and in nitrite levels. TH administration also increased PGC-1α expression in the AMIT group. In conclusion, TH effects seem to involve a modulation of eNOS expression and an improvement in NO bioavailability in the infarcted heart.
authors.affiliation: Laboratório de Fisiologia Cardiovascular, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, sala 01, Porto Alegre, RS, CEP 90050170, Brazil.
authors.forename: Alexandre Luz
authors.initials: AL
authors.lastname: de Castro
authors.affiliation: Laboratório de Fisiologia Cardiovascular, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, sala 01, Porto Alegre, RS, CEP 90050170, Brazil.
authors.forename: Angela Vicente
authors.initials: AV
authors.lastname: Tavares
authors.affiliation: Laboratório de Fisiologia Cardiovascular, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, sala 01, Porto Alegre, RS, CEP 90050170, Brazil.
authors.forename: Rafael Oliveira
authors.initials: RO
authors.lastname: Fernandes
authors.affiliation: Laboratório de Fisiologia Cardiovascular, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, sala 01, Porto Alegre, RS, CEP 90050170, Brazil.
authors.forename: Cristina
authors.initials: C
authors.lastname: Campos
authors.affiliation: Laboratório de Fisiologia Cardiovascular, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, sala 01, Porto Alegre, RS, CEP 90050170, Brazil.
authors.forename: Adriana
authors.initials: A
authors.lastname: Conzatti
authors.affiliation: Laboratório de Fisiologia Cardiovascular, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, sala 01, Porto Alegre, RS, CEP 90050170, Brazil.
authors.forename: Rafaela
authors.initials: R
authors.lastname: Siqueira
authors.affiliation: Laboratório de Fisiologia Cardiovascular, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, sala 01, Porto Alegre, RS, CEP 90050170, Brazil.
authors.forename: Tânia Regina G
authors.initials: TR
authors.lastname: Fernandes
authors.affiliation: Departamento de Fisiologia e Farmacologia, Universidade Federal de Pelotas, Campus Universitário Capão do Leão, Pelotas, RS, CEP 96900010, Brazil.
authors.forename: Paulo Cavalheiro
authors.initials: PC
authors.lastname: Schenkel
authors.affiliation: Laboratório de Fisiologia Cardiovascular, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, sala 01, Porto Alegre, RS, CEP 90050170, Brazil.
authors.forename: Carmem L
authors.initials: CL
authors.lastname: Sartório
authors.affiliation: Universidad de Buenos Aires, C1053ABJ, Buenos Aires, Argentina.
authors.forename: Susana
authors.initials: S
authors.lastname: Llesuy
authors.affiliation: Laboratório de Fisiologia Cardiovascular, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, sala 01, Porto Alegre, RS, CEP 90050170, Brazil.
authors.forename: Adriane
authors.initials: A
authors.lastname: Belló-Klein
authors.affiliation: Laboratório de Fisiologia Cardiovascular, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, sala 01, Porto Alegre, RS, CEP 90050170, Brazil. alsanderaraujo@hotmail.com.
authors.forename: Alex Sander
authors.initials: AS
authors.lastname: da Rosa Araujo
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D006352:Heart Ventricles / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D009569:Nitric Oxide / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D013974:Thyroxine / Q000008:administration & dosage* / Q000494:pharmacology; D014284:Triiodothyronine / Q000008:administration & dosage* / Q000494:pharmacology
chemical_list: D017382:Reactive Oxygen Species; D014284:Triiodothyronine; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D013974:Thyroxine
keywords: Heart failure; Nitric oxide; Oxidative stress; Thyroid hormones