Selective increase of angiotensin(1-7) and its receptor in hearts of spontaneously hypertensive rats subjected to physical training.
In the present study we investigated the effects of physical training on plasma and cardiac angiotensin(1-7) [Ang(1-7)] levels. In addition, possible changes in expression of the Ang(1-7) Mas receptor in the heart were also evaluated. Normotensive Wistar rats and spontaneously hypertensive rats (SHR) were subjected to an 8 week period of 5% overload swimming training. Blood pressure was determined by a tail-cuff system. Heart and left ventricle weights and cardiomyocyte diameter were analysed to evaluate cardiac hypertrophy. Radioimmunoassay was used to measure angiotensin levels. Expression of Mas was determined by semi-quantitative polymerase chain reaction, immunofluorescence and Western blotting. Physical training induced cardiac hypertrophy in Wistar rats and SHR. A significant decrease of plasma angiotensin II (Ang II) levels in both strains was also observed. Strikingly, trained SHR, but not trained Wistar rats, showed a twofold increase in left ventricular Ang(1-7) levels. No significant changes were observed in plasma Ang(1-7) and left ventricular Ang II concentrations in either strain. Furthermore, Mas mRNA and protein expression in left ventricle were substantially increased in trained SHR. The physical training protocol used did not change blood pressure in either strain. These results suggest that the beneficial effects induced by swimming training in hypertensive rats might include an augmentation of Ang(1-7) and its receptor in the heart.
Filho
Ary Gomes
AG
Department of Physiology and Biophysics, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
Ferreira
Anderson J
AJ
Santos
Sérgio Henrique S
SH
Neves
Sílvia R S
SR
Silva Camargos
Elizabeth R
ER
Becker
Lenice K
LK
Belchior
Hindiael A
HA
Dias-Peixoto
Marco Fabricio
MF
Pinheiro
Sérgio V B
SV
Santos
Robson A S
RA
D000803:Angiotensin I / Q000097:blood / Q000378:metabolism*; D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D015153:Blotting, Western; D006332:Cardiomegaly / Q000473:pathology; D007150:Immunohistochemistry; D008297:Male; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism*; D010446:Peptide Fragments / Q000097:blood / Q000378:metabolism*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D011918:Rats, Inbred SHR; D017208:Rats, Wistar; D011945:Receptors, Angiotensin / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013550:Swimming / Q000502:physiology
D010446:Peptide Fragments; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D011945:Receptors, Angiotensin; D043562:Receptors, G-Protein-Coupled; D000803:Angiotensin I; C118790:angiotensin I (1-7)