Cardiovascular effects produced by micro-injection of angiotensin-(1-7) on vasopressor and vasodepressor sites of the ventrolateral medulla.
In this study, we determined the cardiovascular effects produced by micro-injection of the heptapeptide Angiotensin-(1-7) [Ang-(1-7)] into the rat ventrolateral medulla (VLM). Micro-injection of Ang-(1-7) into the rostral VLM and the caudal pressor area of the VLM produced significant increases in arterial pressure, comparable to that observed with micro-injection of Ang II. The changes in arterial pressure were associated with more variable changes in heart rate (HR) (usually tachycardia). On the other hand, micro-injection of Ang-(1-7) into the caudal depressor area induced decreases in arterial pressure and HR. The results suggest that, besides Ang II, Ang-(1-7) is involved in the mediation of the cardiovascular actions of the renin-angiotensin system in the VLM.
Silva
L C
LC
Departamento de Fisiologia e Biofísica, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
Fontes
M A
MA
Campagnole-Santos
M J
MJ
Khosla
M C
MC
Campos
R R
RR
Guertzenstein
P G
PG
Santos
R A
RA
D000803:Angiotensin I; D000804:Angiotensin II / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects*; D008297:Male; D008526:Medulla Oblongata / Q000187:drug effects / Q000502:physiology*; D008845:Microinjections; D009928:Organ Specificity; D010446:Peptide Fragments / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012084:Renin-Angiotensin System / Q000187:drug effects
D010446:Peptide Fragments; D000804:Angiotensin II; D000803:Angiotensin I; C118790:angiotensin I (1-7)