Importance of Proximal Tubular Fluid Output in Regulating Long-Term Urinary Sodium Excretion in Health and Disease

Observations have been made regarding the effects of long-term exercise training on blood pressure, renal sodium handling and renal renin–angiotensin–aldosterone (RAS) intracellular pathways in conscious, trained Okamoto–Aoki spontaneously hypertensive rats (SHR) and Wistar Kyoto (WKy) normotensive rats, compared with appropriate age-matched sedentary SHR and WKy. To evaluate the influence of exercise training on renal function and RAS, receptors and intracellular angiotensin II (AngII) pathway compounds were used respectively, and lithium clearance and western blot methods were utilised. The current study demonstrated that increased blood pressure in SHR was blunted and significantly reduced by long-term swim training between the ages of 6 and 16 weeks. Additionally, the investigators observed an increased fractional urinary sodium excretion in trained SHR (SHRT) rats, compared with sedentary SHR (SHRS), despite a significantly decreased creatinine clearance (CCr). Furthermore, immunoblotting analysis demonstrated a decreased expression of AT1R in the entire kidney of TSHR rats, compared with SSHR. Conversely, the expression of the AT2R, in both sedentary and trained SHR, was unchanged. The present study may indicate that, in the kidney, long-term exercise exerts a modulating effect on AngII receptor expression. In fact, the present study indicates an association of increasing natriuresis, reciprocal changes in renal AngII receptors and intracellular pathway proteins with the fall in blood pressure levels observed in TSHR rats compared with age-matched SSHR rats.

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Proximal tubule response in aldosterone escape

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1989.256.1.r86 ◽

1989 ◽

Vol 256 (1) ◽

pp. R86-R90 ◽

Cited By ~ 3

Author(s):

J. M. Gonzalez-Campoy ◽

J. Kachelski ◽

J. C. Burnett ◽

J. C. Romero ◽

J. P. Granger ◽

...

Keyword(s):

Proximal Tubule ◽

Sodium Excretion ◽

Plasma Renin ◽

Fractional Excretion ◽

Urinary Sodium Excretion ◽

Urinary Sodium ◽

Sodium Reabsorption ◽

Hormonal Changes ◽

Proximal Tubular ◽

Temporal Profiles

The response of the proximal tubule to chronic aldosterone administration (15 micrograms.kg-1.day-1) was evaluated in eight conscious female mongrel dogs. Temporal profiles between hemodynamic and hormonal changes and the fractional excretions of sodium and lithium were established. Aldosterone infusion resulted in a significant decrease in urinary sodium excretion from 9.2 +/- 1.3 to 5.8 +/- 0.9 meq/h after 1 day, returning to normal by the 5th day. These changes in urinary sodium excretion were associated with significant elevations of the mean arterial pressure (MAP) from 105 +/- 5 to 111 +/- 6 mmHg and plasma atrial natriuretic factor concentrations (ANF) from 30 +/- 2 to 57 +/- 7 pg/ml beginning the 1st day of infusion. Plasma renin activity (PRA), on the other hand, was depressed by aldosterone, falling below the level of detectability. The fractional excretion of lithium increased significantly by day 2 of aldosterone infusion (from 29 +/- 3 to 44 +/- 6%), reflecting the proximal tubular response to the above changes. We conclude that the proximal tubule responds to increases in MAP and ANF and decreases in PRA during aldosterone infusion by decreasing sodium reabsorption. Subsequent nephron segments must also respond to the volume expansion produced by aldosterone, since the sustained proximal tubule natriuretic response is insufficient to explain all of escape.

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Short-Term Effects of Salt Restriction via Home Dishes Do Not Persist in the Long Term: A Randomized Control Study

Nutrients ◽

10.3390/nu12103034 ◽

2020 ◽

Vol 12 (10) ◽

pp. 3034

Author(s):

Sachiko Maruya ◽

Ribeka Takachi ◽

Maki Kanda ◽

Misako Nakadate ◽

Junko Ishihara

Keyword(s):

Salt Concentration ◽

Sodium Excretion ◽

Salt Intake ◽

Controlled Trial ◽

Urinary Sodium Excretion ◽

Urinary Sodium ◽

Long Term Effects ◽

Low Sodium ◽

Short And Long Term

Salt intake reduction is crucial to prevent non-communicable diseases (NCDs) globally. This study aimed to investigate the short- and long-term effects of monitoring salt concentration in homemade dishes on reducing salt intake in a Japanese population. A double-blind randomized controlled trial using a 2 × 2 factorial design with two interventions was conducted in 195 participants; they were assigned to both interventions for a group monitoring salt concentration in soups (control: no monitoring) and a group using low-sodium seasoning (control: regular seasoning). We evaluated 24-hour urinary sodium excretions at baseline and after a three-month intervention for the changes as major outcomes, at six- and twelve-months after baseline as long-term follow-up surveys. Urinary sodium excretion decreased in both intervention and control groups after the intervention. However, differences in the change for both monitoring and low-sodium seasoning interventions were statistically non-significant (p = 0.29 and 0.52, respectively). Urinary sodium excretion returned to the baseline level after twelve-months for all groups. Monitoring of salt concentration is ineffective in reducing salt intake for short- and long-term among the people studied in this cohort.

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Faculty Opinions recommendation of Urinary sodium excretion, blood pressure, cardiovascular disease, and mortality: a community-level prospective epidemiological cohort study.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.733790826.793552587 ◽

2018 ◽

Author(s):

Carmine Zoccali ◽

Davide Bolignano

Keyword(s):

Blood Pressure ◽

Cardiovascular Disease ◽

Cohort Study ◽

Sodium Excretion ◽

Urinary Sodium Excretion ◽

Urinary Sodium ◽

Community Level ◽

Epidemiological Cohort

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Multiple, random spot urine sampling for estimating urinary sodium excretion

European Journal of Pediatrics ◽

10.1007/s00431-021-04170-4 ◽

2021 ◽

Author(s):

Gianluigi Ardissino ◽

Antonio Vergori ◽

Cesare Vergori ◽

Laura Martelli ◽

Valeria Daccò ◽

...

Keyword(s):

Sodium Excretion ◽

Urinary Sodium Excretion ◽

Urinary Sodium ◽

Spot Urine ◽

Urine Sampling

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Association between 24-h urinary sodium and potassium excretion and blood pressure among Chinese adults aged 18–69 years

Scientific Reports ◽

10.1038/s41598-021-83049-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Xiaofu Du ◽

Le Fang ◽

Jianwei Xu ◽

Xiangyu Chen ◽

Yamin Bai ◽

...

Keyword(s):

Blood Pressure ◽

Sodium Excretion ◽

Sodium Intake ◽

Urinary Sodium Excretion ◽

Urinary Sodium ◽

Inverse Association ◽

Potassium Excretion ◽

Chinese Adults ◽

Potassium Intake ◽

Sodium And Potassium

AbstractThe direction and magnitude of the association between sodium and potassium excretion and blood pressure (BP) may differ depending on the characteristics of the study participant or the intake assessment method. Our objective was to assess the relationship between BP, hypertension and 24-h urinary sodium and potassium excretion among Chinese adults. A total of 1424 provincially representative Chinese residents aged 18 to 69 years participated in a cross-sectional survey in 2017 that included demographic data, physical measurements and 24-h urine collection. In this study, the average 24-h urinary sodium and potassium excretion and sodium-to-potassium ratio were 3811.4 mg/day, 1449.3 mg/day, and 4.9, respectively. After multivariable adjustment, each 1000 mg difference in 24-h urinary sodium excretion was significantly associated with systolic BP (0.64 mm Hg; 95% confidence interval [CI] 0.05–1.24) and diastolic BP (0.45 mm Hg; 95% CI 0.08–0.81), and each 1000 mg difference in 24-h urinary potassium excretion was inversely associated with systolic BP (− 3.07 mm Hg; 95% CI − 4.57 to − 1.57) and diastolic BP (− 0.94 mm Hg; 95% CI − 1.87 to − 0.02). The sodium-to-potassium ratio was significantly associated with systolic BP (0.78 mm Hg; 95% CI 0.42–1.13) and diastolic BP (0.31 mm Hg; 95% CI 0.10–0.53) per 1-unit increase. These associations were mainly driven by the hypertensive group. Those with a sodium intake above about 4900 mg/24 h or with a potassium intake below about 1000 mg/24 h had a higher risk of hypertension. At higher but not lower levels of 24-h urinary sodium excretion, potassium can better blunt the sodium-BP relationship. The adjusted odds ratios (ORs) of hypertension in the highest quartile compared with the lowest quartile of excretion were 0.54 (95% CI 0.35–0.84) for potassium and 1.71 (95% CI 1.16–2.51) for the sodium-to-potassium ratio, while the corresponding OR for sodium was not significant (OR, 1.28; 95% CI 0.83–1.98). Our results showed that the sodium intake was significantly associated with BP among hypertensive patients and the inverse association between potassium intake and BP was stronger and involved a larger fraction of the population, especially those with a potassium intake below 1000 mg/24 h should probably increase their potassium intake.

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Association of a Tobacco-specific Nitrosamine Carcinogen with Urinary Cotinine, Urinary Sodium Excretion, and Total Energy Intake in Adolescents and Children

Current Medical Science ◽

10.1007/s11596-021-2343-0 ◽

2021 ◽

Vol 41 (2) ◽

pp. 270-278

Author(s):

Jong Weon Choi ◽

Tatsuyoshi Fujii ◽

Noriyoshi Fujii

Keyword(s):

Total Energy ◽

Energy Intake ◽

Sodium Excretion ◽

Urinary Sodium Excretion ◽

Total Energy Intake ◽

Urinary Sodium ◽

Urinary Cotinine

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Urinary sodium excretion and the risk of cardiovascular disease: A community-based cohort study in Taiwan

British Journal Of Nutrition ◽

10.1017/s0007114521001768 ◽

2021 ◽

pp. 1-42

Author(s):

Yi-Jie Wang ◽

Kuo-Lioug Chien ◽

Hsiu-Ching Hsu ◽

Hung-Ju Lin ◽

Ta-Chen Su ◽

...

Keyword(s):

Blood Pressure ◽

Metabolic Syndrome ◽

Systolic Blood Pressure ◽

Sodium Excretion ◽

Urinary Sodium Excretion ◽

Salt Sensitivity ◽

Urinary Sodium ◽

Mediating Effect ◽

Cvd Risk ◽

Media Thickness

Abstract Urinary sodium excretion is a potential risk factor for cardiovascular diseases (CVD). However, the underlying biological mechanisms and effects of salt sensitivity are unclear. The purpose of this study was to characterize the relative contribution of biological factors to the sodium-CVD association. A total of 2112 participants were enrolled in this study. Structured questionnaires and blood and urine samples were obtained. Twenty-four-hour sodium excretion was estimated using a single overnight urine sample. Hypertension, metabolic syndrome, and overweight status were considered to indicate salt sensitivity. Cox proportional hazard models were used to investigate the effects of salt sensitivity on urinary sodium excretion and CVD risk. The traditional mediation approach was used to calculate the proportion of mediation. The mean age (standard deviation) of the 2112 participants was 54.5 (12.2) years, and they were followed up for a mean of 14.1 [8.1] years. Compared with those in the lowest quartile, the highest baseline urinary sodium excretion (>4.2g/24 hours) was associated with a 43% higher CVD risk (hazard ratio, 1.43; 95% confidence interval, 1.02-1.99). Participants with high urinary sodium excretion, hypertension, or metabolic syndrome had a significantly high risk of CVD. The carotid intima-media thickness had the largest mediating effect (accounting for 35% of the sodium-CVD association), followed by systolic blood pressure (33%), left ventricular mass (28%), and diastolic blood pressure (14%). Higher urinary sodium excretion increased the risk of CVD, which was explained largely by carotid media-thickness and systolic blood pressure.

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