Up-regulation of angiotensin-converting enzyme and angiotensin II type 1 receptor in irradiated rats.
OBJECTIVE
To investigate changes in cardiac functional parameters and the cardiac expression of angiotensin-converting enzyme (ACE), angiotensin II type 1 receptor (AT1), procollagen type I (proc-I) and transforming growth factor-ß1 (TGF-ß1) in rats irradiated at heart.


METHODS
Male Wistar rats were irradiated with a single dose of radiation (0, 5, 10 and 15 Gray [Gy]) delivered directly to the heart and the molecular evaluations were performed at various times post-irradiation (two days, 15 days and four months). The expression of ACE, AT1, proc-I and TGF-ß1 were analysed using Real Time-Polymerase Chain Reaction (RT-PCR) and/or Western blotting. Cardiac structural and functional alterations were investigated at the four-month time point by echocardiography and by quantitative methods (stereology).


RESULTS
Rats irradiated with 15 Gy showed a modest reduction in the ejection fraction. Cardiac proc-I, TGF-ß1, ACE and AT1 were also measurably increased.


CONCLUSIONS
Irradiated rat hearts show simultaneous elevations in renin-angiotensin system components AT1 and ACE and cardiac remodeling markers proc-I and TGF-ß1.
Ferreira-Machado
Samara Cristina
SC
Departamento de Biologia Geral – GBG, UFF, Niterói, Rio de Janeiro, Brazil. samararossatti@gmail.com
Rocha
Nazareth De Novaes
Nde N
Mencalha
André Luiz
AL
De Melo
Luiz Dione Barbosa
LD
Salata
Camila
C
Ribeiro
Andréia Fortes
AF
Torres
Thiago Da Silva
Tda S
Mandarim-De-Lacerda
Carlos Alberto
CA
Canary
Paulo César
PC
Peregrino
Antônio Augusto De Freitas
AA
Magalhães
Luís Alexandre Gonçalves
LA
Cabral-Neto
Januário Bispo
JB
Dealmeida
Carlos Eduardo
CE
D000818:Animals; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism; D004307:Dose-Response Relationship, Radiation; D006321:Heart / Q000502:physiology / Q000528:radiation effects; D008297:Male; D032383:Myocytes, Cardiac / Q000166:cytology / Q000528:radiation effects; D007703:Peptidyl-Dipeptidase A / Q000235:genetics* / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D044140:Receptor, Angiotensin, Type 1 / Q000235:genetics* / Q000378:metabolism*; D012084:Renin-Angiotensin System / Q000528:radiation effects; D053773:Transforming Growth Factor beta1 / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation / Q000528:radiation effects*
D024042:Collagen Type I; D044140:Receptor, Angiotensin, Type 1; D053773:Transforming Growth Factor beta1; D007703:Peptidyl-Dipeptidase A