Cardiovascular effects of angiotensin II and angiotensin-(1-7) at the RVLM of trained normotensive rats.
We evaluated the effect of physical training on the cardiovascular responses produced by angiotensin peptides at the rostroventrolateral medulla (RVLM) of non-anesthetized normotensive rats. The RVLM pressor effect induced by Ang II was significantly greater in trained rats, while, in contrast, the Ang-(1-7) pressor effect was significantly smaller in trained in comparison to sedentary rats. In addition, the RVLM microinjection of Losartan (AT1 Ang II receptor antagonist) or A-779 (Ang-(1-7) receptor antagonist) induced opposite effect in trained rats. These results show that exercise training induces a differential RVLM responsiveness to Ang peptides, which was corroborated by the selective antagonists, indicating that the RVLM is a site in the central nervous system involved in the adaptive mechanisms triggered during exercise training.
Becker
Lenice K
LK
Department Physiology and Biophysics, Federal University of Minas Gerais, Avenue Antônio Carlos, 6627-ICB, 31270-901 Belo Horizonte, MG, Brazil.
Santos
Robson A S
RA
Campagnole-Santos
Maria José
MJ
D000803:Angiotensin I; D000804:Angiotensin II / Q000008:administration & dosage*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D006339:Heart Rate / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008526:Medulla Oblongata / Q000187:drug effects* / Q000502:physiology; D008845:Microinjections; D010446:Peptide Fragments / Q000008:administration & dosage*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar
D010446:Peptide Fragments; D000804:Angiotensin II; D000803:Angiotensin I; C118790:angiotensin I (1-7)