Relationship between high salt intake and oxidative stress in essential hypertensive patients

2002 ◽  
Vol 15 (4) ◽  
pp. A128
Author(s):  
E BRAGULAT
2011 ◽  
Vol 301 (2) ◽  
pp. E281-E287 ◽  
Author(s):  
Rocío Perez-Abud ◽  
Isabel Rodríguez-Gómez ◽  
Ana Belén Villarejo ◽  
Juan Manuel Moreno ◽  
Rosemary Wangensteen ◽  
...  

This study assessed salt sensitivity, analyzing the effects of an increased saline intake on hemodynamic, morphological, and oxidative stress and renal variables in experimental thyroid disorders. Six groups of male Wistar rats were used: control, hypothyroid, hyperthyroid, and the same groups treated with salt (8% via food intake). Body weight, blood pressure (BP), and heart rate (HR) were recorded weekly for 6 wk. Finally, BP and HR were recorded directly, and morphological, metabolic, plasma, and renal variables were measured. High-salt intake increased BP in thyroxine-treated rats but not in control or hypothyroid rats. High-salt intake increased cardiac mass in all groups, with a greater increase in hyperthyroid rats. Urinary isoprostanes and H2O2 were higher in hyperthyroid rats and were augmented by high-salt intake in all groups, especially in hyperthyroid rats. High-salt intake reduced plasma thyroid hormone levels in hyperthyroid rats. Proteinuria was increased in hyperthyroid rats and aggravated by high-salt intake. Urinary levels of aminopeptidases (glutamyl-, alanyl-, aspartyl-, and cystinylaminopeptidase) were increased in hyperthyroid rats. All aminopeptidases were increased by salt intake in hyperthyroid rats but not in hypothyroid rats. In summary, hyperthyroid rats have enhanced salt sensitivity, and high-salt intake produces increased BP, cardiac hypertrophy, oxidative stress, and signs of renal injury. In contrast, hypothyroid rats are resistant to salt-induced BP elevation and renal injury signs. Urinary aminopeptidases are suitable biomarkers of renal injury.


2008 ◽  
Vol 31 (2) ◽  
pp. 62 ◽  
Author(s):  
Sowndramalingam Sankaralingam ◽  
Kaushik M Desai ◽  
Thomas W Wilson

Purpose: High salt intake causes hypertension and endothelial dysfunction in young Sprague-Dawley rats. Clofibrate (clof) prevents this salt induced hypertension. We asked whether clof can prevent salt-induced endothelial dysfunction, and if so, its mechanism. We also questioned whether high salt intake can induce endothelial dysfunction without hypertension in older animals. Methods: Young (Y, 5 weeks) and old (O, 53 weeks) male Sprague-Dawley rats were given either vehicle (Con, 20 mM Na2CO3) or 0.9% NaCl (Sal) to drink for three weeks. Some young rats received clof (80 mg/d) in their drinking fluid. After three weeks, we measured mean arterial pressure (MAP), endothelial function, by comparing hypotensive responses to acetylcholine (ACh, endothelium dependent) and sodium nitroprusside (SNP, endothelium independent), plasma total nitrite+nitrate levels (PNOx), by the Griess reaction, and aortic superoxide production by lucigenin chemiluminescence. Results: Carotid artery MAP did not change in O. Sal-Y developed hypertension: 133±3 vs. 114±2 mmHg, P < 0.001, which was prevented by clof: 105±2 mmHg. ACh induced a similar dose dependent hypotensive response in Con-O and Sal-O that was inhibited by L-NAME (100mg/kg i.v.). Responses to ACh were blunted in Sal-Y but not in Con-Y. Further, L-NAME inhibited ACh responses only in Con-Y. The response to SNP was similar in all animals. Importantly, the ACh-induced hypotensive response was potentiated in clof+Sal-Y, an effect which was attenuated by blocking calcium-activated potassium channels (KCa) with a combination of apamin (50 ug/kg i.v.) + charybdotoxin (50 ug/kg i.v.), but not by L-NAME. PNOx was reduced in Sal-Y compared to Con-Y (2.09±0.26 vs. 4.8±0.35 µM, P < 0.001), but not in Sal-O. Aortic superoxide production was higher (P < 0.001) in Sal-Y (2388±40 milliunits/mg/min) than Sal-O (1107±159 milliunits/mg/min), but was reduced by clof (1378±64 milliunits/mg/min; P < 0.001). Conclusions: High salt intake increases oxidative stress in young animals, leading to impaired nitric oxide activity and endothelial dysfunction. Clofibrate prevents endothelial dysfunction partly through reduced O2?- formation but mainly via selective activation of KCa channels. Older animals are resistant to both salt induced hypertension and oxidative stress.


2020 ◽  
Vol 33 (4) ◽  
pp. 371-371
Author(s):  
Hong-yi Wang ◽  
Yong-jie He ◽  
Wei Li ◽  
Fan Yang ◽  
Ning-ling Sun

Abstract Background To survey the relationship between salt intake and blood pressure in hypertensive patients in Beijing. Methods A cross-sectional survey was used. Essential hypertensive patients were enrolled and divided into three groups (low, medium, and high salt intake) according to their 24 h urinary sodium excretion, which was used to access the salt intake. Blood pressure was measured through office measurement and ambulatory blood pressure monitoring. Results A total of 2,241 patients were enrolled with a mean age of 59.5 ± 13.8 years, mean blood pressure of 141.1 ± 18.5/84.6 ± 12.7 mm Hg, and urinary sodium excretion of 163.9 (95% CI 160.3–167.4) mmol [equal to salt intake 9.59 (9.38–9.79) g/d]. There were 1,544 cases from tertiary hospitals and the other 697 cases from community hospitals. Patients from community hospitals took more salt than patients from tertiary hospitals. Patients with high salt intake were younger than patients with low and medium salt intake. There were more males in high salt intake group than in the other two groups. Ambulatory blood pressure monitoring showed that patients with high salt intake had higher mean blood pressure not only in daytime, but also at night. The diastolic blood pressure in patients with medium salt intake was higher than that in patients with low salt intake. Conclusions Higher salt intake was associated with higher ambulatory blood pressure in hypertensive patients. More effort should be made to lower salt intake to improve blood pressure control rate.


2015 ◽  
pp. 303-312 ◽  
Author(s):  
M. VOKURKOVÁ ◽  
H. RAUCHOVÁ ◽  
L. ŘEZÁČOVÁ ◽  
I. VANĚČKOVÁ ◽  
J. ZICHA

Enhanced production of superoxide radicals by nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase in the brain and/or kidney of salt hypertensive Dahl rats has been proposed to participate in the pathogenesis of this form of experimental hypertension. Most information was obtained in young Dahl salt-sensitive (DS) rats subjected to high salt intake prior to sexual maturation. Therefore, the aim of our study was to investigate whether salt hypertension induced in adult DS rats is also accompanied with a more pronounced oxidative stress in the brain or kidney as compared to Dahl salt-resistant (DR) controls. NADPH oxidase activity as well as the content of thiobarbituric acid-reactive substances (TBARS) and conjugated dienes (oxidative index), which indicate a degree of lipid peroxidation, were evaluated in two brain regions (containing either hypothalamic paraventricular nucleus or rostral ventrolateral medulla) as well as in renal medulla and cortex. High salt intake induced hypertension in DS rats but did not modify blood pressure in DR rats. DS and DR rats did not differ in NADPH oxidase-dependent production of ROS, TBARS content or oxidative index in either part of the brain. In addition, high-salt diet did not change significantly any of these brain parameters. In contrast, the enhanced NADPH oxidase-mediated ROS production (without significant signs of increased lipid peroxidation) was detected in the renal medulla of salt hypertensive DS rats. Our findings suggest that there are no signs of enhanced oxidative stress in the brain of adult Dahl rats with salt hypertension induced in adulthood.


2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Kouki Taniguchi ◽  
Satoshi Nagase ◽  
Shigehiro Karashima ◽  
Mitsuhiro Kometani ◽  
Daisuke Aono ◽  
...  

Abstract Salt intake is one of most important environmental factors responsible for triggering the onset of hypertension. Renin-angiotensin-aldosterone system (RAAS) plays a key role in adjusting sodium homeostasis and blood pressure. Recently, the potential role of the gut microbiome (GM) in altering the health of the host has drawn considerable attention. We investigated the impact of intestinal microflora and RAAS in hypertensive patients with low-salt or high-salt intake using an observational study. A total of 239 participants were enrolled and their GMs and clinical backgrounds examined, including the renin-angiotensin-aldosterone system and inflammatory cytokine levels. On the basis of enterotypes—determined by cluster analysis—and salt intake, the participants were classified into four groups, low salt/GM enterotype 1, low salt/GM enterotype 2, high salt/GM enterotype 1, and high salt/GM enterotype 2. The prevalence of hypertension was significantly lower in the low-salt intake (low salt/GM enterotype 1 = 47% vs low salt/GM enterotype 2 = 27%, p = 0.04) groups. No significant difference in the prevalence of hypertension was observed for the two GM enterotype groups with high-salt intake (GM enterotype 1 = 50%, GM enterotype 2 = 47%; p = 0.83). Plasma aldosterone concentration was significantly different among the four groups (p &lt; 0.01). Furthermore, the relative abundance of Blautia, Bifidobacterium, Escherichia-Shigella, Lachnoclostridium, and Clostridium sensu stricto was also significantly different among these enterotypes. This suggested in certain individuals (with specific gut bacteria composition) changing dietary habits—to low salt—would be ineffective for regulating hypertension through RAAS. Our findings provide a new strategy for controlling blood pressure and preventing the development of hypertension through restoring GM homeostasis.


2014 ◽  
Vol 15 (4) ◽  
pp. 498-504 ◽  
Author(s):  
Carol Kotliar ◽  
Pablo Kempny ◽  
Sergio Gonzalez ◽  
Carlos Castellaro ◽  
Pedro Forcada ◽  
...  

2019 ◽  
Vol 317 (6) ◽  
pp. F1623-F1636 ◽  
Author(s):  
Alissa A. Frame ◽  
Franco Puleo ◽  
Kiyoung Kim ◽  
Kathryn R. Walsh ◽  
Elizabeth Faudoa ◽  
...  

Salt sensitivity of blood pressure is characterized by inappropriate sympathoexcitation and renal Na+ reabsorption during high salt intake. In salt-resistant animal models, exogenous norepinephrine (NE) infusion promotes salt-sensitive hypertension and prevents dietary Na+-evoked suppression of the Na+-Cl− cotransporter (NCC). Studies of the adrenergic signaling pathways that modulate NCC activity during NE infusion have yielded conflicting results implicating α1- and/or β-adrenoceptors and a downstream kinase network that phosphorylates and activates NCC, including with no lysine kinases (WNKs), STE20/SPS1-related proline-alanine-rich kinase (SPAK), and oxidative stress response 1 (OxSR1). In the present study, we used selective adrenoceptor antagonism in NE-infused male Sprague-Dawley rats to investigate the differential roles of α1- and β-adrenoceptors in sympathetically mediated NCC regulation. NE infusion evoked salt-sensitive hypertension and prevented dietary Na+-evoked suppression of NCC mRNA, protein expression, phosphorylation, and in vivo activity. Impaired NCC suppression during high salt intake in NE-infused rats was paralleled by impaired suppression of WNK1 and OxSR1 expression and SPAK/OxSR1 phosphorylation and a failure to increase WNK4 expression. Antagonism of α1-adrenoceptors before high salt intake or after the establishment of salt-sensitive hypertension restored dietary Na+-evoked suppression of NCC, resulted in downregulation of WNK4, SPAK, and OxSR1, and abolished the salt-sensitive component of hypertension. In contrast, β-adrenoceptor antagonism attenuated NE-evoked hypertension independently of dietary Na+ intake and did not restore high salt-evoked suppression of NCC. These findings suggest that a selective, reversible, α1-adenoceptor-gated WNK/SPAK/OxSR1 NE-activated signaling pathway prevents dietary Na+-evoked NCC suppression, promoting the development and maintenance of salt-sensitive hypertension.


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