In aortas of spontaneously hypertensive rats (SHRs), excessive dietary salt causes down-regulation of soluble guanylate cyclase (sGC) followed by decreased cyclic GMP production, which leads to impairment of the vascular relaxation response to nitric oxide (NO). The present study aimed to elucidate whether this impaired NO/cyclic GMP system results secondarily ...

To determine the influence of chronic ANG II infusion on urinary, plasma, and renal tissue levels of immunoreactive endothelin (ET), ANG II (65 ng/min) or saline vehicle was delivered via osmotic minipump in male Sprague-Dawley rats given either a high-salt diet (10% NaCl) or normal-salt diet (0.8% NaCl). High-salt diet ...

BACKGROUND: This study compared directly the renal effects of two selective cyclooxygenase (COX)-2 inhibitors (rofecoxib and celecoxib) with naproxen (dual COX-1/COX-2 inhibitor) and placebo in healthy elderly subjects on a sodium-replete diet. METHODS: A total of 67 elderly subjects stabilized in the clinic for weight and urinary sodium on a ...

The elevation of renal sympathetic nervous activity (SNA) is a possible cause of blood pressure (BP) elevation. Although a high-fat diet (FAT) often induces BP elevation in animals, the effect of FAT on renal SNA in animals is not consistent between studies. Thus, we compared the basal levels of efferent ...

Hypertension is associated with impaired fibrinolysis. Both angiotensin receptor blockers (ARB) and the DASH (Dietary Approaches to Stop Hypertension) diet effectively lower blood pressure in hypertensive patients. Some evidence suggests that treatment with ARBs could increase fibrinolysis, however, data is conflicting. The impact of the DASH diet on fibrinolytic parameters ...

The effect of dietary sodium restriction on insulin, lipids, and blood pressure has been controversial. Evidence suggests that adverse short-term effects in response to very low-salt diets do not persist long-term with modest sodium restriction. In this study, the effects of modest dietary sodium restriction (60 and 120 mmol sodium) ...

The amount of sodium chloride in the diet of industrialized nations far exceeds physiological requirements. The impact of abundant dietary salt on skeletal health has yet to be established, but is potentially detrimental through increased urinary calcium losses. We examined the effect of increased dietary sodium chloride on urine calcium ...

The aim of the present study was to investigate whether plasma concentration of proANP(1-30), the N-terminal fragment of the atrial natriuretic peptide prohormone, or 24-hour urinary excretion of urodilatin reflects the degree of salt sensitivity in hypertension-prone individuals. Plasma concentration of proANP(1-30) and urinary urodilatin excretion were determined at baseline, ...

OBJECTIVE: Diabetic subjects have a high prevalence of hypertension, increased total body exchangeable sodium levels, and an impaired ability to excrete a sodium load. This study assessed the effect of dietary sodium restriction on the efficacy of losartan in hypertensive subjects with type 2 diabetes and albumin excretion rates of ...

Clinical disorders of extracellular fluid (ECF) volume regulation are often associated with changes in plasma urea concentration. To investigate possible renal causes, we measured the relative abundance of the urea transporters UT-A1, UT-A2, and UT-A3 in renal medulla of rats with aldosterone-induced NaCl retention. ECF volume-expanded rats received aldosterone by ...

Weight gain by adult cat fleas, Ctenocephalidesfelis (Bouché), was influenced primarily by the concentrations of protein and sodium chloride in the feeding solution. After 48 h of feeding, fleas fed whole blood weighed almost twice as much as fleas fed plasma or hemolyzed blood and 1.25 times as much as ...

To determine the extent to which dietary sodium modulates aldosterone-induced cardiovascular damage, and to determine whether increased dietary potassium can prevent this damage, we used the Nomega-nitro-L-arginine methyl ester (L-NAME)/angiotensin II (Ang II) rat model of cardiac injury. This model is dependent on the presence of aldosterone for the occurrence ...

Atrial natriuretic peptide (ANP) has negative modulatory effects on a variety of pathophysiological mechanisms; i.e., it inhibits hypoxia-induced pulmonary vasoconstriction and vascular remodeling and facilitates natriuresis and vasorelaxation in NaCl-supplemented subjects. We have previously demonstrated organ-selective potentiation of ANP in the pulmonary circulation of hypoxia-adapted animals by local downregulation of ...

To determine the role of endothelin-1 (ET-1) and its receptors in salt-sensitive hypertension induced by sensory nerve degeneration, selective ET(A) antagonist (ABT-627) and ET(B) antagonist (A-192621) were used. Newborn Wistar rats were given vehicle or 50 mg/kg capsaicin subcutaneously on the first and second days of life. After the weaning ...

We report the case of a 14-year-old boy with instantaneous orthostatic hypotension (INOH) with symptoms of orthostatic intolerance. We investigated the effect of high sodium intake on hemodynamics and circulatory responses to orthostatic stress using Portapres. Moreover, a multifrequency bioelectrical impedance method was used to confirm increased plasma volume. Although ...

In rats maintained on a high salt diet (H/S) to suppress basal renal angiotensinogen levels, angiotensin II (Ang II) infusion for 13 days increased renal angiotensinogen mRNA and protein, thus providing a mechanism for further augmentation of intrarenal Ang II levels. The present study tested the hypothesis that enhanced intrarenal ...

OBJECTIVES: We investigated the influence of hyperhomocysteinemia and high salt intake on sodium handling, oxidative state, vascular endothelial function and blood pressure in a rat model. METHODS: Eight-week-old male Sprague-Dawley rats were divided into subgroups and maintained for 4 weeks prior to experimentation on either control chow containing 0.36% methionine ...

Increasing renal pelvic pressure increases afferent renal nerve activity (ARNA) by a prostaglandin E2 (PGE2)-mediated release of substance P (SP) from renal pelvic sensory nerves. We examined whether the ARNA responses were modulated by high- and low-sodium diets. Increasing renal pelvic pressure resulted in greater ARNA responses in rats fed ...

In the Dahl salt-sensitive hypertensive rat, a diet containing L-arginine, the natural substrate for nitric oxide synthase, abrogates the hypertension. We postulated that nitric oxide synthase inhibition might induce a salt-sensitive form of hypertension and that this salt sensitivity might be linked to a loss of the regulatory effect of ...

Hyponatremia, defined as a serum sodium < 135 mmol/l, is one of the most commonly encountered and serious electrolyte disorders of clinical medicine. The predominant cause of hyponatremia is an inappropriate elevation of circulating vasopressin levels relative to serum osmolality or the 'syndrome of inappropriate antidiuretic hormone secretion' (SIADH). Fortunately, ...

BACKGROUND: A basolateral Ba(2+)-sensitive KCl cotransporter has previously been proposed as participating in basolateral K+ recycling and transepithelial NaCl reabsorption in the thick ascending limb of Henle's loop (TAL). The aim of the present study was to answer the question as to whether this cotransporter plays a role in transepithelial ...

OBJECTIVE: To determine the relationship between angiotensinogen (ANG) genotype and blood pressure response to the dietary patterns of the Dietary Approaches to Stop Hypertension (DASH) trial. The angiotensin converting enzyme (ACE) gene was also tested. DESIGN: The DASH trial was a randomized outpatient feeding study comparing the effects on blood ...

Epidemiological and experimental studies have suggested that dietary salt may play a role in airway responsiveness. We have previously shown that a low salt diet improves and a high salt diet exacerbates post-exercise pulmonary function in individuals with exercise-induced asthma. The aim of this study was to determine the influence ...

Two pen trials were conducted in Utah, altitude 1,630 m, with Large White female turkey poults to evaluate effects of dietary Na and chloride (Cl) concentrations on live performance and deaths caused by spontaneous cardiomyopathy (STC, "round heart") from 0 to 35 d of age. A randomized block 2 x ...

To define the role of the renin-angiotensin-aldosterone system in a novel salt-sensitive model, neonatal Wistar rats were given capsaicin (50 mg/kg sc) on the first and second days of life. After weaning, male rats were divided into the following six groups and treated for 3 wk with: control + normal ...

Although the role of sodium in hypertension has been documented extensively, its effect on large arteries has not been well documented. We examined the effect of high-sodium (8%) diet and the diuretic indapamide (IND) on systemic hemodynamics and aortic wall structure and composition in collagen, elastin, and hyaluronan. Four groups ...

1. Cyclic guanosine monophosphate (cyclic GMP)-mediated mechanism plays an important role in vasodilatation and blood pressure regulation. We investigated the effects of high salt intake on the nitric oxide (NO) - cyclic GMP signal transduction pathway regulating relaxation in aortas of spontaneously hypertensive rats (SHR). 2. Four-week-old SHR and normotensive ...

Theoretically, we humans should be better adapted physiologically to the diet our ancestors were exposed to during millions of years of hominid evolution than to the diet we have been eating since the agricultural revolution a mere 10,000 years ago, and since industrialization only 200 years ago. Among the many ...

OBJECTIVE: To define the role of the type 1 angiotensin II (AT1) and type II (AT2) receptors in the development of salt-sensitive hypertension induced by sensory nerve degeneration. DESIGN AND METHODS: Neonatal Wistar rats were given capsaicin 50 mg/kg s.c. on the first and second days of life. After weaning, ...

We investigated the antihypertensive effect of Brand's Essence of Chicken (BEC), a popular chicken extract used as a traditional remedy, using deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Animals were unilaterally nephrectomized, and then separated into a sham-operated group (sham group) and a DOCA-salt-treated group. The latter was further separated into a ...

Cyclosporine use is highly associated with the development of salt-sensitive hypertension. We hypothesized that subtle renal injury induced by cyclosporine could lead to salt sensitivity. Cyclosporine nephropathy was induced by treatment for 4 weeks with cyclosporine (15 mg/kg/day) on a low sodium (0.05%) diet, followed by stopping cyclosporine and placement ...

BACKGROUND: Previously, we reported that elevated extracellular potassium concentration in vitro inhibited proliferation and migration of vascular smooth muscle cells, formation of free radical compounds by macrophages, and reduced platelet sensitivity to agonists. More recently, we described a reduction in neointimal proliferation after balloon angioplasty injury in the carotid arteries ...

While the debate regarding the effectiveness of dietary sodium restriction raged, the Dietary Approaches to Stop Hypertension (DASH) research group showed that a diet rich in fruits, vegetables, and low-fat dairy products can reduce blood pressure in the general population and people with Stage I hypertension. The original DASH diet ...

Rats fed a high-fructose diet represent an animal model for insulin resistance and hypertension. We recently showed that a high-fructose diet containing vegetable oil but a normal sodium/potassium ratio induced mild insulin resistance with decreased insulin receptor substrate-1 tyrosine phosphorylation in the liver and muscle of normal rats. In the ...

Sodium restriction is often used as an adjunct in the treatment of conditions characterized by endothelial dysfunction, such as hypertension and heart or kidney disease. However, the effect of sodium restriction on endothelial function is not known. Therefore, male Wistar rats were studied after a fixed salt diet had been ...

Two studies were performed to determine the quantitative relationship between salt intake and urinary volume (U(v)) in humans. In study 1, 104 untreated hypertensives were studied on the fifth day of a high- and a low-salt diet. The 24-hour U(v) was 2.2 L (urinary sodium [U(Na)] 277 mmol) on the ...

Intravenous (iv) infusion of the angiotensin II (ANG II) receptor blocker saralasin in resting conscious dogs during physiological pertubations, such as hypotension and prolonged hypoxia, indicates the presence of an ANG II drive to increase respiration and decrease the arterial partial pressure of CO2 (PaCO2). In contrast, in eupneic resting ...

This study aimed to assess the impact of cyclooxygenase-2 (COX-2) on the secretion and expression of renin in the kidney cortex. For this purpose renocortical COX-2 expression was moderately stimulated by a low-salt diet or strongly stimulated (increase in mRNA about fivefold) by the combination of a low-salt diet and ...

1. Nitric oxide synthase (NOS)-inhibited genetically hypertensive (GH) rats on normal and low-sodium diets were additionally given valsartan or felodipine to establish whether low-Na intake would have extra beneficial effects on blood pressure and cardiovascular structure. 2. Male GH rats on normal or low-Na diets were treated with the NOS ...

The pathogenesis of salt-sensitive hypertension remains poorly defined, but a role for nitric oxide (NO) has been suggested. The Dahl/Rapp salt-sensitive rat possesses a defect in NO synthesis that is overcome by supplementation with L-arginine, which increases NO and cGMP production and prevents salt-sensitive hypertension. An S714P mutation of inducible ...

The beta-adrenergic receptor (betaAR) kinase (betaARK1) is a G protein-coupled receptor kinase (GRK) that controls cardiac betaAR signaling via receptor phosphorylation, leading to desensitization. We have observed in mice that chronic isoproterenol administration results in increased myocardial levels of betaARK1 activity, suggesting that adrenergic activation can regulate cardiac betaARK1 expression. ...

The tachycardic, pressor, and renal sympathoexcitatory responses produced by administration of the gamma-aminobutyric acid antagonist bicuculline into the paraventricular nucleus of the rat are attenuated by the administration of losartan, an angiotensin II type 1 receptor antagonist, into the ipsilateral rostroventrolateral medulla. Therefore, excitatory synaptic inputs to pressor neurons in ...

OBJECTIVE: The aim of this study was to evaluate the role of the renal nerves in the regulation of renin synthesis in normotensive rats at different sodium balance. METHODS: Forty-eight male Sprague-Dawley rats were divided in six experimental groups, combining three diets at different NaCl content (normal 0.4%, low 0.04% ...

OBJECTIVE: To compare the volumes of renomedullary interstitial cell (RMIC) lipid droplets (putative source of vasodepressor substance) in spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats on high and low salt diets as an indication of whether the renomedullary vasodepressor system of the SHR is defective. METHODS: Ten-week-old male SHR and ...

The aim of the present study was to determine the molecular responses of the main salt-reabsorbing systems in the distal nephron to changes of salt load of the organism. For this purpose we analysed messenger ribonucleic acid (mRNA) levels for the bumetanide-sensitive Na+K+2Cl- cotransporter (BSC1), the thiazide-sensitive Na+Cl- cotransporter (TSC), ...

Dahl salt-sensitive (DS) rats fed high-salt diet exert compensated left ventricular (LV) hypertrophy and eventually develop heart failure. Oxidative stress has been shown to be involved in myocardial remodeling and failure and thus might play an important role in this transition from hypertrophy to failure. We measured the amount of ...

The purpose of this study was to evaluate an intracellular solution with polyethylene glycol (PEG, molecular weight 20,000) as an impermeant, compared with University of Wisconsin (UW) and Euro-Collins (EC) solutions, after a 48-h cold storage (CS). The normothermic isolated perfused rat kidney (IPK) technique was used to assess renal ...

Dietary recalls and urine assays provide different metrics for assessing sodium and potassium intakes. Means, variances, and correlations of data obtained from these two modes of measurement differ. Pooling of these data is not straightforward, and results from studies employing the different modes may not be comparable. To explore differences ...

OBJECTIVES: The objective was to determine whether or not dietary salt intake affects the relative bioavailability of oral quinine. Salt intake has been shown to alter quinidine bioavailability. METHODS: The pharmacokinetic properties of oral quinine sulphate (600 mg salt) were investigated in seven healthy Caucasian volunteers, in a randomised, crossover ...

BACKGROUND: There are conflicting reports regarding the effect of salt sensitivity on the calciuric response to salt, perhaps because of gender differences and different modes of salt administration. We tested the hypothesis that the calciuric response to dietary salt would not differ for male Dahl salt-sensitive (S) and salt-resistant (R) ...