IQUIFIB   02644
INSTITUTO DE QUIMICA Y FISICOQUIMICA BIOLOGICAS "PROF. ALEJANDRO C. PALADINI"
Unidad Ejecutora - UE
capítulos de libros
Título:
Central effects of angiotensin-(1-7)
Autor/es:
GIRONACCI MM, PEÑA C
Libro:
Function of Neuropeptides at Central Nervous System
Editorial:
Research Signpost
Referencias:
Año: 2008;
Resumen:
Angiotensin
(Ang) (1-7) constitutes an important functional end-product of the
renin-angiotensin system endogenously formed from Ang I or Ang II through the
catalytic activity of angiotensin-converting enzyme (ACE) 2, prolyl
endopeptidase, thimet oligopeptidase or neutral endopeptidase 24.11. Ang-(1-7)
lacks the pressor, dipsogenic or stimulatory effect on aldosterone release
characteristic of Ang II. In contrast, it produces vasodilation, natriuresis
and diuresis and inhibits angiogenesis and cell growth.
At the
central level, Ang-(1-7) acts in sites involved in the control of
cardiovascular function, thus contributing to blood pressure regulation. For
instance, in contrast to Ang II, intracerebroventricular infusion of Ang-(1-7)
has been shown to improve the baroreflex control of heart rate. In fact,
endogenous Ang-(1-7) is involved in the improvement of baroreflex sensitivity
observed in spontaneously hypertensive rats during central ACE inhibition
suggesting that it may contribute to the beneficial effects of ACE inhibitors.
In addition, Ang-(1-7) caused blood pressure reduction when it was injected
into the nucleus tractus solitarii, caudal ventrolateral medulla,
paraventricular nucleus and anterior hypothalamic area, while an increase in
blood pressure was observed when the peptide was injected into the rostral
ventrolateral medulla. The lowering blood pressure effect caused by Ang-(1-7)
at the central level may result from its inhibitory activity on norepinephrine
release.
Taken
together, these findings suggest that Ang-(1-7), acting at peripheral and
central sites, plays an important role in the regulation of cardiovascular and
renal function and in the pathophysiology of hypertension.