Effect Of Dietary Sodium Chloride Research Articles

Novel Paradigms of Salt and Hypertension.

Salt resistance/sensitivity refers specifically to the effect of dietary sodium chloride (salt) intake on BP. Increased dietary salt intake promotes an early and uniform expansion of extracellular fluid volume and increased cardiac output. To compensate for these hemodynamic changes and maintain constant BP in salt resistance, renal and peripheral vascular resistance falls and is associated with an increase in production of nitric oxide. In contrast, the decline in peripheral vascular resistance and the increase in nitric oxide are impaired or absent in salt sensitivity, promoting an increase in BP in these individuals. Endothelial dysfunction may pose a particularly significant risk factor in the development of salt sensitivity and subsequent hypertension. Vulnerable salt-sensitive populations may have in common underlying endothelial dysfunction due to genetic or environmental influences. These individuals may be very sensitive to the hemodynamic stress of increased effective blood volume, setting in motion untoward molecular and biochemical events that lead to overproduction of TGF-β, oxidative stress, and limited bioavailable nitric oxide. Finally, chronic high-salt ingestion produces endothelial dysfunction, even in salt-resistant subjects. Thus, the complex syndrome of salt sensitivity may be a function of the endothelium, which is integrally involved in the vascular responses to high salt intake.

Supplementation of sodium chloride in diets to improve the meat quality of Pacific white shrimp,Litopenaeus vannamei, reared in low-salinity water

To investigate the effect of dietary sodium chloride (NaCl) on meat quality of white shrimp (Litopenaeus vannamei) reared in low-salinity (2 g L−1) water, shrimp were distributed into four groups (treatments T-1, T-2, T-3 and control) with three replicates. All shrimps were completely randomised stocked into 12 tanks at an initial density of 40 shrimps per tank. Diets for the control, T-1, T-2 and T-3 groups consisted of the basal diet supplemented with 0 g kg−1, 10 g kg−1, 20 g kg−1 and 40 g kg−1 of NaCl respectively. After 50 days, shrimps in T-3 showed significantly better (P < 0.05) moisture, crude protein and ash than those of the control and T-1. Higher muscle Na content was observed (P < 0.05) in T-3 than that of the control. Significant increases (P < 0.05) in contents of inosinic acid, total free amino acid (TFAA) and essential free amino acid (EFAA) were also found in T-3. Texture assays showed significant differences (P < 0.05) in hardness, adhesiveness and springiness between group T-3 as compared with those of T-1 and control. It indicated that dietary supplementation of NaCl appeared to be a promising practice to improve meat quality of white shrimp reared in low-salinity waters.

Corrigendum to “Effects of Dietary Sodium Chloride on Health Parameters in Mature Cats” [J Feline Med Surg 2009; 11: 435–441

Corrigendum to “Effects of Dietary Sodium Chloride on Health Parameters in Mature Cats” [J Feline Med Surg 2009; 11: 435–441

Modulation of adenosine receptor expression in the proximal tubule: a novel adaptive mechanism to regulate renal salt and water metabolism

about 180 liters of filtrate are produced by the human kidneys every day, with more than 99% of the filtered salt and water being subsequently reabsorbed along the nephron. In view of this high level of renal filtration, even slight alterations in the balance between filtration and reabsorption will

Effect of dietary sodium chloride on gastro-oesophageal reflux: A randomized controlled trial

Objective.It has been suggested that a high consumption of sodium chloride (NaCl) is associated with reflux symptoms. The objective of this study was to investigate the effect of increased dietary NaCl intake on gastro-oesophageal reflux and reflux mechanisms. Material and methods. In this double-blind, placebo-controlled, crossover study 10 healthy male subjects received 5 g NaCl or placebo in capsules per day for one week, after which concurrent manometric, pH and impedance monitoring was carried out for 4.5 h. Results. Oesophageal acid exposure time (pH < 4) was similar for placebo (median 11% (25th 3–75th 36)) and NaCl (9% (1–36)). No differences in the numbers of reflux episodes were found for NaCl (16 (13.5–22)) and placebo (23 (14.8–27)). Furthermore, similar numbers of liquid acid reflux episodes (placebo 12 (6.5–17.3); NaCl 10 (2.3–14.3)), liquid weakly acidic reflux episodes (placebo 5.5 (4–12.3); NaCl 6.5 (3–10.8)) and gaseous reflux episodes (placebo 1 (0–1.8); NaCl 2 (0–3)) were seen. In both conditions transient lower oesophageal sphincter relaxations (TLOSRs) were the most common reflux mechanism, followed by swallow-induced reflux. High salt intake lowered LOS pressure overall and in the first postprandial hour (p<0.01). Conclusions. High dietary sodium intake does not increase gastro-oesophageal reflux in healthy volunteers, despite a decrease in LOS pressure.

Review: Role of angiotensin in central regulation of sympathetic activity: effect of dietary sodium chloride.

Review: Role of angiotensin in central regulation of sympathetic activity: effect of dietary sodium chloride.

The effect of dietary sodium chloride on some osmoregulatory parameters of the teleost, Oreochromis niloticus, after transfer from freshwater to seawater.

The aim of this work was to determine the effects of supplemental dietary sodium chloride on salt water acclimation of tilapia Oreochromis niloticus. Fish were fed a basal diet supplemented with NaCl (8%) during three weeks in fresh water (FW) and then transferred to salt water (SW) at 15 and 20‰. Changes in plasma osmolality, chloride ion concentration (Cl−), plasma level of cortisol and gill Na+, K+-ATPase activity were measured at 6, 12, 24, 48, 72 and 168 h after transfer to 15‰SW, while the higher strength SW group (20‰) was only monitored up to 24 h. Morphological changes in the gill mitochondria-rich (MR) cells were examined in relation to environmental salinity. The changes associated with dietary NaCl were sporadic and of small magnitude. The plasma osmolality and Cl− increased immediately after transfer up to 12–24 h, but fish fed dietary salt (S) showed lower values than the control group (C). The S group showed higher plasma levels of cortisol than the control, which maintained its initial levels during the experiment. Gill Na+, K+-ATPase activity of the S group began to increase in the first hours after transfer, reaching maximum at 12 h and returned to basal level at 24 h, while the control group maintained basal levels. The differences between gill Na+, K+-ATPase activity of S and C fish were significant (p < 0.05) at 12 h. Transmission electron microscopy (TEM) revealed that MR cells in SW show more mitochondria and a more developed tubular system arising from the basolateral membrane. The MR cells of both groups frequently formed a multicellular complex in SW, consisting of a main MR and one or more accessory cells. Such complexes are rarely observed in FW. Some MR cells of fish fed supplemented dietary salt displayed convex apical membrane in FW.

Regulation of renal adenosine A 1 receptors: effect of dietary sodium chloride

The influence of dietary NaCl on the regulation of renal adenosine A 1 receptors was investigated in the rat. Renal membranes from rats fed on a diet low (0.04%) in NaCl showed a 46% increase in B max for the binding of [ 3H]-1,3-dipropyl-8-cyclopentylxanthine ([ 3H]DPCPX), a selective adenosine A 1 receptor antagonist, compared to membranes from rats fed on a normal diet (0.4% NaCl). Conversely, a high NaCl diet (4.0%) resulted in a 37% decrease in B max. Levels of renal adenosine A 1 receptor mRNA were 65% lower in rats on a high salt diet. Autoradiographic studies showed that, for the inner medullary collecting ducts, a low NaCl diet resulted in a 30% increase in [ 3H]DPCPX binding with a 39% decrease noted in rats maintained on a high salt diet. The results indicate that changes in adenosine A 1 receptor density may represent a novel mechanism whereby the kidneys adapt to changes in salt load.

Calciuric Effects of Short-Term Dietary Loading of Protein, Sodium Chloride and Potassium Citrate in Prepubescent Girls

Objective: Studies using adult human subjects indicate that dietary protein and sodium chloride have negative effects on the retention of calcium by increasing urinary calcium excretion, while alkaline potassium improves calcium retention along with decreasing urinary calcium losses. This study investigated the effect of these dietary factors on acute urinary calcium excretion in 14 prepubescent girls age 6.7 to 10.0 years.Methods: Subjects provided a fasting urine sample then consumed a meal containing one of five treatments: moderate protein (MP) providing 11.8 g protein, moderate protein plus 26 mmol sodium chloride (MP+Na), high protein (HP) providing 28.8 g protein, high protein plus 26 mmol sodium chloride (HP+Na), or high protein plus 32 mmol potassium as tripotassium citrate (HP+K). Urine was collected at 1.5 and 3.0 hours after the meal. Supplemental protein was given as 80:20 casein:lactalbumin. Test meals were isocaloric, and unless intentionally altered, components of interest except phosphate were equal between treatments. Each subject completed all five treatments.Results: Urinary calcium excretion rose after the meal, peaking at 1.5 hours. There were no significant differences in calcium excretion between treatments at any time point. The high protein treatments did not result in a significant increase in either net acid or sulfate excretion at 1.5 hours compared to moderate protein. Dietary sodium chloride had no effect on urinary sodium or calcium excretion over the 3 hours. After the potassium treatment, sodium excretion increased (p≤0.002) and net acid excretion decreased (p<0.001) compared to other treatments at 1.5 hours.Conclusions: In children, a simultaneous increase in protein and phosphorus due to increased milk protein intake did not increase acute urinary calcium excretion. An effect of dietary sodium chloride on acute urinary calcium excretion was not observed. Both these findings were similar to those of adult studies previously conducted in the same laboratory using similar format and treatments. Potassium citrate was not hypocalciuric in children, a response differing from that for adults, who have shown a decrease in acute urinary calcium excretion in response to alkaline potassium treatment. Further characterization of calciuric responses to dietary factors is required for children, who may differ from adults in many respects.

Effect of dietary sodium chloride on insulin receptor number and mRNA levels in rat kidney

Insulin has been postulated to play a role in the pathophysiology of essential hypertension via an antinatriuretic action. To further explain the sodium insulin interaction in the kidney, we studied effects of different salt intakes on insulin receptor binding and mRNA levels in tissues from rats maintained on 0.07%, 0.3%, or 7.5% NaCl for 14 days. Scatchard analysis of competition data from in situ autoradiography studies resulted in curvilinear profiles, indicating the presence of either two classes of receptors or a single class of receptors with a negative cooperative hormone-receptor interaction. When data were analyzed using the two-site model, binding capacity of the high-affinity receptor site was significantly less in high-salt-fed rats. No significant differences between dietary groups were observed in apparent dissociation constants of the two receptor sites or in maximal binding capacity of the low-affinity, high-capacity site. Analysis of insulin binding to glomeruli, cortex, outer medulla, and inner medulla indicated that the high-salt diet was associated with decreased receptor density in all regions studied. Insulin receptor mRNA, as quantified by Northern and slot blot analysis, was inversely related to salt intake in absence of a change in plasma glucose, insulin, and corticosterone levels. Both 7.2- and 9.4-kb transcripts were similarly affected by dietary sodium content. Plasma renin concentration and renal renin mRNA levels were decreased but blood pressure was not affected by high-salt diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of Dietary Sodium Chloride on Red Drum Juveniles in Waters of Various Salinities

Abstract Three 8-week feeding trials were conducted to determine the effects of supplemental dietary salts on growth and osmoregulation of juvenile red drums (Sciaenops ocellatus) at various water salinities. In each experiment, sodium chloride was added to a basal diet composed of semipurified and practical ingredients; the basal diet provided intrinsic levels of 0.80% Cl, 0.84% K, and 0.92% Na on a dry-matter basis. In fresh water, red drums fed the basal diet supplemented with NaCI at 2% had significantly (P < 0.05) greater weight gain and feed efficiency than fish given the basal diet alone. In brackish water (6‰ salinity), fish given the diet supplemented with NaCI at 2% had weight gains that were numerically but not significantly (P = 0.076) greater than gains offish fed the basal diet. In full-strength artificial seawater (35‰), fish fed diets supplemented with NaCI at 2 and 10% had weight gains not significantly (P = 0.23) different from those of fish fed the basal diet, and those fed the diet sup...

The interactive effects of dietary sodium chloride and calcium on cardiovascular stress responses

Blood pressure increases associated with salt loading in the spontaneously hypertensive rat (SHR) are attenuated with increased dietary calcium. To assess the cardiovascular effects of these nutrients during stress, blood pressure and sympathoadrenal responses to stress were compared in salt-sensitive SHRs fed diets containing normal (0.73%) or high (8.0%) NaCl combined with either low (0.2%) or high (2.0%) calcium. NaCl-loaded rats showed increased blood pressure and exaggerated plasma epinephrine changes during restraint stress. Elevated blood pressure responses to exogenous NE were also observed with high salt intake. Supplementary calcium reduced blood pressure and attenuated the hypertensive effect of NaCl during restraint stress. Animals fed the high calcium diets had lower plasma epinephrine levels while vascular reactivity was not affected. The results indicate that increased sympathoadrenal activity and vascular reactivity contribute to elevated blood pressure and exaggerated pressor responses produced by NaCl loading in the salt-sensitive SHR. However, the hypotensive effects of dietary calcium appear to be related to sympathoadrenal activity but not vascular reactivity.

Effect of dietary sodium chloride on growth, food intake and conversion efficiency in rainbow trout ( Salmo gairdneri Richardson)

The effect of increased dietary salt on growth and nutrition of rainbow trout was investigated using two types of salt-enriched diets: (a) commercial trout food reconstituted to contain 4.5%, 9.2% and 11.6% NaCl, (b) isonitrogenous and isocaloric diets containing similar salt levels, i.e. no nutrient dilution caused by salt addition. Food conversion efficiency of fish fed the isonitrogeous diets was not affected by the added salt, but both conversion efficiency and growth rate were adversely influenced by the salt-supplemented commercial food. The insignificant differences in protein efficiency ratio among fish fed on different levels of salt indicates that reduction in food conversion efficiency is probably the result of protein dilution rather than the added salt. Food intake and appetite were not affected by dietary salt, and feeding to satiation enhanced growth in all feeding treatments, but this feeding regime did not alter the differences in growth rate between normally fed fish and those fed on salty diets.

Effect of dietary sodium chloride and posture on plasma immunoreactive atrial natriuretic peptide concentrations in man.

The effect of changes of dietary sodium chloride intake and posture on plasma atrial natriuretic peptide concentration and renal function was studied in 11 normal human volunteers. Plasma atrial natriuretic peptide concentration was higher in the upright posture on a high than it was on a medium or low salt diet. On the medium and high but not on the low salt diet the concentration increased significantly on adoption of the supine posture. Creatinine, sodium, lithium and fractional lithium clearances, fractional distal sodium excretion and total distal water and sodium reabsorption, which were estimated by the lithium clearance technique, were significantly higher on the high than on the low salt diet. The medium salt intake gave intermediate values. Heart rate while upright was significantly higher on the low than on either the medium or the high salt diets. Systolic blood pressure was unaffected by salt intake. Diastolic blood pressure in the supine position was significantly higher on the low than on the medium or high salt diets. Both plasma noradrenaline concentrations and plasma renin activity were significantly higher on the low than on the high salt diet. Values on the medium salt intake were intermediate. Plasma concentrations of both hormones were higher in the upright than in the supine posture on all three salt intakes. The data are consistent with the hypothesis that atrial natriuretic peptide contributes to the cardiovascular and renal adjustments to changes in dietary sodium chloride, and the possible role of the peptide is discussed.

Effect of Dietary Sodium Chloride, Protein, and Strain Difference upon Water Consumption and Fecal Moisture Content of Broiler Breeder Males

Water consumption of birds and moisture content and water-holding capacity of feces were determined for caged immature broiler breeder males of Strains A and B. Both strains were fed a commercial type corn-soy diet containing 16% protein and .35% sodium chloride. The breeder males of Strain A were also fed different levels of dietary protein (12, 14, 16, and 18%) for 3 weeks and sodium chloride (0, .17, .35, and .70%) for 3 weeks to evaluate the effect on the criteria listed. A commercial type feeding and water restriction program was used.Strain A males consumed more water and had a significantly greater moisture content and a significantly reduced moisture-holding capacity of feces than did Strain B males when fed the same diet. The dietary levels of salt used had no effect on water consumption (off feed day), fecal moisture, or water holding capacity of the feces in strain A males. Water consumption on feed day significantly increased as dietary salt increased. Although decreasing dietary protein below 16% had no influence on water consumption, it did significantly decrease fecal moisture and increase the water-holding capacity of feces.It was concluded that strain differences in water consumption exist and that the large quantity of water consumed and high fecal moisture content of Strain A males was not related to dietary salt or protein.

Effect of sodium chloride on longevity in mice.

The effects of dietary sodium chloride on the longevity, body weight, and food consumption in a normotensive strain (A/J) of mice was studied. Four groups of 50 mice each were fed diets containing 0.5 (control group), 1.5, 2.5, and 4.5% sodium chloride. The mean life span was 115.2 wk in the control group, and 115.5, 110,5, and 116.1 wk for groups 2, 3, and 4, with no significant differences from the control group. No differences were present in food consumption, but a graded weight loss was present after the 20th wk, which persisted throughout the experiment. No significant effect of salt loading was demonstrable on the extravascular fluid movement in either acute experiments or in the long-term dietary sodium chloride groups.