Protective axis of the renin-angiotensin system in the brain

Clin Sci (Lond). 2014 Sep;127(5):295-306. doi: 10.1042/CS20130450.

Abstract

The RAS (renin-angiotensin system) is composed of two arms: the pressor arm containing AngII (angiotensin II)/ACE (angiotensin-converting enzyme)/AT1Rs (AngII type 1 receptors), and the depressor arm represented by Ang-(1-7) [angiotensin-(1-7)]/ACE2/Mas receptors. All of the components of the RAS are present in the brain. Within the brain, Ang-(1-7) contributes to the regulation of BP (blood pressure) by acting at regions that control cardiovascular function such that, when Ang-(1-7) is injected into the nucleus of the solitary tract, caudal ventrolateral medulla, paraventricular nucleus or anterior hypothalamic area, a reduction in BP occurs; however, when injected into the rostral ventrolateral medulla, Ang-(1-7) stimulates an increase in BP. In contrast with AngII, Ang-(1-7) improves baroreflex sensitivity and has an inhibitory neuromodulatory role in hypothalamic noradrenergic neurotransmission. Ang-(1-7) not only exerts effects related to BP regulation, but also acts as a cerebroprotective component of the RAS by reducing cerebral infarct size and neuronal apoptosis. In the present review, we provide an overview of effects elicited by Ang-(1-7) in the brain, which suggest a potential role for Ang-(1-7) in controlling the central development of hypertension.

Publication types

  • Review

MeSH terms

  • Angiotensin I / metabolism
  • Angiotensin II / physiology
  • Angiotensin-Converting Enzyme 2
  • Animals
  • Baroreflex / drug effects
  • Blood Pressure / drug effects
  • Brain / metabolism
  • Brain / physiology*
  • Neurotransmitter Agents / metabolism
  • Peptide Fragments / metabolism
  • Peptidyl-Dipeptidase A / physiology
  • Proto-Oncogene Mas
  • Proto-Oncogene Proteins / physiology
  • Rats
  • Receptor, Angiotensin, Type 1 / physiology
  • Receptors, G-Protein-Coupled / physiology
  • Renin-Angiotensin System / physiology*
  • Signal Transduction / physiology

Substances

  • Neurotransmitter Agents
  • Peptide Fragments
  • Proto-Oncogene Mas
  • Proto-Oncogene Proteins
  • Receptor, Angiotensin, Type 1
  • Receptors, G-Protein-Coupled
  • Angiotensin II
  • Angiotensin I
  • Peptidyl-Dipeptidase A
  • Ace2 protein, rat
  • Angiotensin-Converting Enzyme 2
  • angiotensin I (1-7)