Central endogenous angiotensin-(1-7) protects against aldosterone/NaCl-induced hypertension in female rats

Baojian Xue, Zhongming Zhang, Ralph F. Johnson, Fang Guo, Meredith Hay, Alan Kim Johnson

Research output: Contribution to journalArticle

21 Scopus citations

Abstract

In comparison to male rodents, females are protected against angiotensin (ANG) II- and aldosterone (Aldo)-induced hypertension. However, the mechanisms underlying this protective effect are not well understood. ANG-(1-7) is formed from ANG II by angiotensin-converting enzyme 2 (ACE2) and has an antihypertensive effect in the central nervous system (CNS). The present study tested the hypothesis that central ANG-(1-7) plays an important protective role in attenuating the development of Aldo/NaCl-hypertension in female rats. Systemic infusion of Aldo into intact female rats with 1% NaCl as their sole drinking fluid resulted in a slight increase in blood pressure (BP). Intracerebroventricular (icv) infusion of A-779, an ANG-(1-7) receptor (Mas-R) antagonist, significantly augmented the pressor effects of Aldo/NaCl. In contrast, systemic Aldo/NaCl induced a significant increase in BP in ovariectomized (OVX) female rats, and central infusion of ANG-(1-7) significantly attenuated this Aldo/NaCl pressor effect. The inhibitory effect of ANG-(1-7) on the Aldo/NaCl pressor effect was abolished by concurrent infusion of A-779. RT-PCR analyses showed that there was a corresponding change in mRNA expression of several renin-angiotensin system components, estrogen receptors and an NADPH oxidase subunit in the lamina terminalis. Taken together these results suggest that female sex hormones regulate an antihypertensive axis of the brain renin-angiotensin system involving ACE2/ANG-(1-7)/Mas-R that plays an important counterregulatory role in protecting against the development of Aldo/NaCl-induced hypertension.

Original languageEnglish (US)
Pages (from-to)H699-H705
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume305
Issue number5
DOIs
StatePublished - Sep 1 2013

Keywords

  • Aldosterone
  • Angiotensin-(1-7)
  • Blood pressure
  • Central nervous system

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

Fingerprint Dive into the research topics of 'Central endogenous angiotensin-(1-7) protects against aldosterone/NaCl-induced hypertension in female rats'. Together they form a unique fingerprint.

  • Cite this