Immunohistochemical expression of intrarenal renin angiotensin system components in response to tempol in rats fed a high salt diet.

Aim: To determine the effect of tempol in normal rats fed high salt on arterial pressure and the balance between antagonist components of the renal renin-angiotensin system.

Methods: Sprague-Dawley rats were fed with 8% NaCl high-salt (HS) or 0.4% NaCl (normal-salt, NS) diet for 3 wk, with or without tempol (T) (1 mmol/L, administered in drinking water).

Reduction of eNOS in Vascular Smooth Muscle by Salt Independently of Hypertension.

Background: Endothelial nitric oxide synthase (eNOS) is known to be expressed in endothelium and smooth muscle cells of arteries. The aim of this study was to investigate the expression of eNOS in intimal and medial layer of aorta from rats fed with a high salt diet and its modulation by losartan and tempol.

Methods: Rats were fed during three weeks with: normal salt diet (NS, 0.

Renal overexpression of atrial natriuretic peptide and hypoxia inducible factor-1α as adaptive response to a high salt diet.

In the kidney, a high salt intake favors oxidative stress and hypoxia and causes the development of fibrosis. Both atrial natriuretic peptide (ANP) and hypoxia inducible factor (HIF-1α) exert cytoprotective effects. We tested the hypothesis that renal expression of ANP and HIF-1α is involved in a mechanism responding to the oxidative stress produced in the kidneys of rats chronically fed a high sodium diet.

Salt-induced downregulation of renal aquaporins is prevented by losartan.

Aims: The purpose of this study was to investigate the expression of aquaporin-1 (AQP-1) and aquaporin-2 (AQP-2) in the renal tubule of rats fed with a high-salt diet and its modulation by the AT1 receptor blocker losartan.

Main Methods: The experiments were performed in four groups of rats fed for 3 weeks with the following diets: regular rat chow (NS); high-salt (8% NaCl) chow (HS), NS plus losartan (NS-L) and HS plus losartan (HS-L). Losartan (40 mg x kg(-1)) was administered in the drinking water.

High-sodium diet promotes a profibrogenic reaction in normal rat kidneys: effects of Tempol administration.

Background: Studies carried out in vitro have recently shown that salt loading induces an increasing mechanical stretch and a flow-induced superoxide production in the thick ascending limb of Henle's loop. In this regard, we hypothesized that the oxidative stress induced by salt overload could stimulate inflammatory and fibrogenic signaling pathways in normal rats.

Methods: Sprague Dawley rats were fed with an 8% NaCl high- (HS) or 0.

Different protective actions of losartan and tempol on the renal inflammatory response to acute sodium overload.

The aim of this work was to study the role of local intrarenal angiotensin II (Ang II) and the oxidative stress in the up-regulation of pro-inflammatory cytokines expression observed in rats submitted to an acute sodium overload. Sprague-Dawley rats were infused for 2 h with isotonic saline solution (Control group) and with hypertonic saline solution alone (Na group), plus the AT1 receptor antagonist losartan (10 mg kg(-1) in bolus) (Na-Los group), or plus the superoxide dismutase mimetic tempol (0.5 mg min(-1) kg(-1)) (Na-Temp group).

Renal protective role of atrial natriuretic peptide in acute sodium overload-induced inflammatory response.

Background: The present study was performed to explore the effect of exogenous infusions of atrial natriuretic peptide (ANP) on the early inflammatory response during acute sodium overload in normal rats.

Methods: Sprague Dawley rats were exposed to acute sodium overload (Na 1.5 M).