25
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

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

      Read this article at

      ScienceOpenPublisherPubMed
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          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.

          Related collections

          Author and article information

          Journal
          Vascul. Pharmacol.
          Vascular pharmacology
          1879-3649
          1537-1891
          Feb 2014
          : 60
          : 2
          Affiliations
          [1 ] Department of Pharmacology, Universidade Federal do Paraná, Curitiba, PR, Brazil; Department of Physiology, Georgia Health Sciences University, Augusta, GA, USA.
          [2 ] Institute of Biological Sciences, Medical and Health, Universidade Paranaense, Umuarama, PR, Brazil.
          [3 ] Department of Pharmacology, Universidade Federal do Paraná, Curitiba, PR, Brazil.
          [4 ] Department of Medicine, Georgia Health Sciences University, Augusta, GA, USA.
          [5 ] Department of Physiology, Georgia Health Sciences University, Augusta, GA, USA.
          [6 ] Department of Pharmacology, Universidade Federal do Paraná, Curitiba, PR, Brazil; Laboratory of Cardiovascular Pharmacology, Department of Pharmacology, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil. Electronic address: j.e.silva.santos@ufsc.br.
          Article
          S1537-1891(13)00140-7
          10.1016/j.vph.2013.12.001
          24321189
          39107b7a-b159-4ffb-9ddc-fc0cefe1ae8a
          Copyright © 2013 Elsevier Inc. All rights reserved.
          History

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

          Comments

          Comment on this article