Enhanced angiotensin-converting enzyme activity and systemic reactivity to angiotensin II in normotensive rats exposed to a high-sodium diet

Sandra Crestani, Arquimedes Gasparotto Júnior, Maria C A Marques, Jennifer C Sullivan, R Clinton Webb, J. Eduardo Da Silva-Santos

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

A high salt diet is associated with reduced activity of the renin-angiotensin-aldosterone system (RAAS). However, normotensive rats exposed to high sodium do not show changes in systemic arterial pressure. We hypothesized that, despite the reduced circulating amounts of angiotensin II induced by a high salt diet, the cardiovascular system's reactivity to angiotensin II is increased in vivo, contributing to maintain arterial pressure at normal levels. Male Wistar rats received chow containing 0.27% (control), 2%, 4%, or 8% NaCl for six weeks. The high-sodium diet did not lead to changes in arterial pressure, although plasma levels of angiotensin II and aldosterone were reduced in the 4% and 8% NaCl groups. The 4% and 8% NaCl groups showed enhanced pressor responses to angiotensin I and II, accompanied by unchanged and increased angiotensin-converting enzyme activity, respectively. The 4% NaCl group showed increased expression of angiotensin II type 1 receptors and reduced expression of angiotensin II type 2 receptors in the aorta. In addition, the hypotensive effect of losartan was reduced in both 4% and 8% NaCl groups. In conclusion these results explain, at least in part, why the systemic arterial pressure is maintained at normal levels in non-salt sensitive and healthy rats exposed to a high salt diet, when the functionality of RAAS appears to be blunted, as well as suggest that angiotensin II has a crucial role in the vascular dysfunction associated with high salt intake, even in the absence of hypertension.

Original languageEnglish (US)
Pages (from-to)67-74
Number of pages8
JournalVascular Pharmacology
Volume60
Issue number2
DOIs
StatePublished - Feb 1 2014

Fingerprint

Peptidyl-Dipeptidase A
Angiotensin II
Sodium
Diet
Arterial Pressure
Salts
Renin-Angiotensin System
Angiotensin Type 2 Receptor
Angiotensin I
Angiotensin Type 1 Receptor
Losartan
Cardiovascular System
Aldosterone
Blood Vessels
Aorta
Wistar Rats
Hypertension

Keywords

  • Angiotensin II receptors
  • Arterial pressure
  • High salt
  • Losartan
  • Vascular reactivity

ASJC Scopus subject areas

  • Physiology
  • Molecular Medicine
  • Pharmacology

Cite this

Enhanced angiotensin-converting enzyme activity and systemic reactivity to angiotensin II in normotensive rats exposed to a high-sodium diet. / Crestani, Sandra; Gasparotto Júnior, Arquimedes; Marques, Maria C A; Sullivan, Jennifer C; Webb, R Clinton; Da Silva-Santos, J. Eduardo.

In: Vascular Pharmacology, Vol. 60, No. 2, 01.02.2014, p. 67-74.

Research output: Contribution to journalArticle

Crestani, Sandra ; Gasparotto Júnior, Arquimedes ; Marques, Maria C A ; Sullivan, Jennifer C ; Webb, R Clinton ; Da Silva-Santos, J. Eduardo. / Enhanced angiotensin-converting enzyme activity and systemic reactivity to angiotensin II in normotensive rats exposed to a high-sodium diet. In: Vascular Pharmacology. 2014 ; Vol. 60, No. 2. pp. 67-74.
@article{449661ed4bf24fbe8759ae1e36d1bc48,
title = "Enhanced angiotensin-converting enzyme activity and systemic reactivity to angiotensin II in normotensive rats exposed to a high-sodium diet",
abstract = "A high salt diet is associated with reduced activity of the renin-angiotensin-aldosterone system (RAAS). However, normotensive rats exposed to high sodium do not show changes in systemic arterial pressure. We hypothesized that, despite the reduced circulating amounts of angiotensin II induced by a high salt diet, the cardiovascular system's reactivity to angiotensin II is increased in vivo, contributing to maintain arterial pressure at normal levels. Male Wistar rats received chow containing 0.27{\%} (control), 2{\%}, 4{\%}, or 8{\%} NaCl for six weeks. The high-sodium diet did not lead to changes in arterial pressure, although plasma levels of angiotensin II and aldosterone were reduced in the 4{\%} and 8{\%} NaCl groups. The 4{\%} and 8{\%} NaCl groups showed enhanced pressor responses to angiotensin I and II, accompanied by unchanged and increased angiotensin-converting enzyme activity, respectively. The 4{\%} NaCl group showed increased expression of angiotensin II type 1 receptors and reduced expression of angiotensin II type 2 receptors in the aorta. In addition, the hypotensive effect of losartan was reduced in both 4{\%} and 8{\%} NaCl groups. In conclusion these results explain, at least in part, why the systemic arterial pressure is maintained at normal levels in non-salt sensitive and healthy rats exposed to a high salt diet, when the functionality of RAAS appears to be blunted, as well as suggest that angiotensin II has a crucial role in the vascular dysfunction associated with high salt intake, even in the absence of hypertension.",
keywords = "Angiotensin II receptors, Arterial pressure, High salt, Losartan, Vascular reactivity",
author = "Sandra Crestani and {Gasparotto J{\'u}nior}, Arquimedes and Marques, {Maria C A} and Sullivan, {Jennifer C} and Webb, {R Clinton} and {Da Silva-Santos}, {J. Eduardo}",
year = "2014",
month = "2",
day = "1",
doi = "10.1016/j.vph.2013.12.001",
language = "English (US)",
volume = "60",
pages = "67--74",
journal = "Vascular Pharmacology",
issn = "1537-1891",
publisher = "Elsevier Inc.",
number = "2",

}

TY - JOUR

T1 - Enhanced angiotensin-converting enzyme activity and systemic reactivity to angiotensin II in normotensive rats exposed to a high-sodium diet

AU - Crestani, Sandra

AU - Gasparotto Júnior, Arquimedes

AU - Marques, Maria C A

AU - Sullivan, Jennifer C

AU - Webb, R Clinton

AU - Da Silva-Santos, J. Eduardo

PY - 2014/2/1

Y1 - 2014/2/1

N2 - A high salt diet is associated with reduced activity of the renin-angiotensin-aldosterone system (RAAS). However, normotensive rats exposed to high sodium do not show changes in systemic arterial pressure. We hypothesized that, despite the reduced circulating amounts of angiotensin II induced by a high salt diet, the cardiovascular system's reactivity to angiotensin II is increased in vivo, contributing to maintain arterial pressure at normal levels. Male Wistar rats received chow containing 0.27% (control), 2%, 4%, or 8% NaCl for six weeks. The high-sodium diet did not lead to changes in arterial pressure, although plasma levels of angiotensin II and aldosterone were reduced in the 4% and 8% NaCl groups. The 4% and 8% NaCl groups showed enhanced pressor responses to angiotensin I and II, accompanied by unchanged and increased angiotensin-converting enzyme activity, respectively. The 4% NaCl group showed increased expression of angiotensin II type 1 receptors and reduced expression of angiotensin II type 2 receptors in the aorta. In addition, the hypotensive effect of losartan was reduced in both 4% and 8% NaCl groups. In conclusion these results explain, at least in part, why the systemic arterial pressure is maintained at normal levels in non-salt sensitive and healthy rats exposed to a high salt diet, when the functionality of RAAS appears to be blunted, as well as suggest that angiotensin II has a crucial role in the vascular dysfunction associated with high salt intake, even in the absence of hypertension.

AB - A high salt diet is associated with reduced activity of the renin-angiotensin-aldosterone system (RAAS). However, normotensive rats exposed to high sodium do not show changes in systemic arterial pressure. We hypothesized that, despite the reduced circulating amounts of angiotensin II induced by a high salt diet, the cardiovascular system's reactivity to angiotensin II is increased in vivo, contributing to maintain arterial pressure at normal levels. Male Wistar rats received chow containing 0.27% (control), 2%, 4%, or 8% NaCl for six weeks. The high-sodium diet did not lead to changes in arterial pressure, although plasma levels of angiotensin II and aldosterone were reduced in the 4% and 8% NaCl groups. The 4% and 8% NaCl groups showed enhanced pressor responses to angiotensin I and II, accompanied by unchanged and increased angiotensin-converting enzyme activity, respectively. The 4% NaCl group showed increased expression of angiotensin II type 1 receptors and reduced expression of angiotensin II type 2 receptors in the aorta. In addition, the hypotensive effect of losartan was reduced in both 4% and 8% NaCl groups. In conclusion these results explain, at least in part, why the systemic arterial pressure is maintained at normal levels in non-salt sensitive and healthy rats exposed to a high salt diet, when the functionality of RAAS appears to be blunted, as well as suggest that angiotensin II has a crucial role in the vascular dysfunction associated with high salt intake, even in the absence of hypertension.

KW - Angiotensin II receptors

KW - Arterial pressure

KW - High salt

KW - Losartan

KW - Vascular reactivity

UR - http://www.scopus.com/inward/record.url?scp=84893802958&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84893802958&partnerID=8YFLogxK

U2 - 10.1016/j.vph.2013.12.001

DO - 10.1016/j.vph.2013.12.001

M3 - Article

C2 - 24321189

AN - SCOPUS:84893802958

VL - 60

SP - 67

EP - 74

JO - Vascular Pharmacology

JF - Vascular Pharmacology

SN - 1537-1891

IS - 2

ER -