CHEMICAL METHOD FOR THE DETERMINATION OF URINARY ALDOSTERONE

1957 ◽  
Vol 35 (6) ◽  
pp. 425-443 ◽  
Author(s):  
Wojciech Nowaczynski ◽  
Erich Koiw ◽  
Jacques Genest

A new method of purification of crude neutral extracts of urine for the isolation and determination of aldosterone is presented. The specificity and accuracy of the method depend upon the high degree of purity of the aldosterone isolated. The assertion that the substance isolated is aldosterone is based on the mobilities in the three chromatographic systems used, on the typical ultraviolet absorption curve, on the satisfactory agreement between the values obtained by ultraviolet absorption and by blue tetrazolium reaction, and by the typical chromogen spectra in concentrated sulphuric acid and in 100% phosphoric acid. Values obtained in nine normal subjects on ordinary diets vary from 2.2 to 10 μg. per day with a mean of 5.1. Illustrations of results obtained during pregnancy, anxiety state, and periods of high potassium and combined high sodium and potassium intake are presented.

1957 ◽  
Vol 35 (1) ◽  
pp. 425-443 ◽  
Author(s):  
Wojciech Nowaczynski ◽  
Erich Koiw ◽  
Jacques Genest

A new method of purification of crude neutral extracts of urine for the isolation and determination of aldosterone is presented. The specificity and accuracy of the method depend upon the high degree of purity of the aldosterone isolated. The assertion that the substance isolated is aldosterone is based on the mobilities in the three chromatographic systems used, on the typical ultraviolet absorption curve, on the satisfactory agreement between the values obtained by ultraviolet absorption and by blue tetrazolium reaction, and by the typical chromogen spectra in concentrated sulphuric acid and in 100% phosphoric acid. Values obtained in nine normal subjects on ordinary diets vary from 2.2 to 10 μg. per day with a mean of 5.1. Illustrations of results obtained during pregnancy, anxiety state, and periods of high potassium and combined high sodium and potassium intake are presented.


1968 ◽  
Vol 58 (1) ◽  
pp. 27-37 ◽  
Author(s):  
Jürg Müller

ABSTRACT Three groups of rats received respectively the following drinking fluids for two weeks: sucrose 5%; NaCl 0.154 m + sucrose; KCl 0.154 m+ sucrose. Aldosterone biosynthesis by quartered adrenal glands of these animals was studied under various in vitro conditions. Adrenals from rats drinking sucrose alone produced significantly more aldosterone under all conditions of incubation than adrenals from rats drinking NaCl, which produced more corticosterone and deoxycorticosterone. Tissue from animals drinking NaCl converted less unlabelled progesterone, 11β-hydroxyprogesterone, deoxycorticosterone and corticosterone to aldosterone and incorporated less tritiated pregnenolone, progesterone, deoxycorticosterone and corticosterone into aldosterone. Adrenals from rats drinking KCl produced less aldosterone than adrenals from rats drinking sucrose under basal conditions but not under stimulation by ACTH or potassium ions. In both groups, the production of corticosterone and of deoxycorticosterone was the same under various test conditions. These results indicate that a high sodium intake inactivates one or both enzymes essential for the conversion of corticosterone to aldosterone, whereas a high potassium intake has no significant effect on these later steps of aldosterone biosynthesis.


BMJ ◽  
2019 ◽  
pp. l772 ◽  
Author(s):  
Martin O’Donnell ◽  
Andrew Mente ◽  
Sumathy Rangarajan ◽  
Matthew J McQueen ◽  
Neil O’Leary ◽  
...  

AbstractObjectiveTo evaluate the joint association of sodium and potassium urinary excretion (as surrogate measures of intake) with cardiovascular events and mortality, in the context of current World Health Organization recommendations for daily intake (<2.0 g sodium, >3.5 g potassium) in adults.DesignInternational prospective cohort study.Setting18 high, middle, and low income countries, sampled from urban and rural communities.Participants103 570 people who provided morning fasting urine samples.Main outcome measuresAssociation of estimated 24 hour urinary sodium and potassium excretion (surrogates for intake) with all cause mortality and major cardiovascular events, using multivariable Cox regression. A six category variable for joint sodium and potassium was generated: sodium excretion (low (<3 g/day), moderate (3-5 g/day), and high (>5 g/day) sodium intakes) by potassium excretion (greater/equal or less than median 2.1 g/day).ResultsMean estimated sodium and potassium urinary excretion were 4.93 g/day and 2.12 g/day, respectively. After a median follow-up of 8.2 years, 7884 (6.1%) participants had died or experienced a major cardiovascular event. Increasing urinary sodium excretion was positively associated with increasing potassium excretion (unadjusted r=0.34), and only 0.002% had a concomitant urinary excretion of <2.0 g/day of sodium and >3.5 g/day of potassium. A J-shaped association was observed of sodium excretion and inverse association of potassium excretion with death and cardiovascular events. For joint sodium and potassium excretion categories, the lowest risk of death and cardiovascular events occurred in the group with moderate sodium excretion (3-5 g/day) and higher potassium excretion (21.9% of cohort). Compared with this reference group, the combinations of low potassium with low sodium excretion (hazard ratio 1.23, 1.11 to 1.37; 7.4% of cohort) and low potassium with high sodium excretion (1.21, 1.11 to 1.32; 13.8% of cohort) were associated with the highest risk, followed by low sodium excretion (1.19, 1.02 to 1.38; 3.3% of cohort) and high sodium excretion (1.10, 1.02 to 1.18; 29.6% of cohort) among those with potassium excretion greater than the median. Higher potassium excretion attenuated the increased cardiovascular risk associated with high sodium excretion (P for interaction=0.007).ConclusionsThese findings suggest that the simultaneous target of low sodium intake (<2 g/day) with high potassium intake (>3.5 g/day) is extremely uncommon. Combined moderate sodium intake (3-5 g/day) with high potassium intake is associated with the lowest risk of mortality and cardiovascular events.


1980 ◽  
Vol 58 (1) ◽  
pp. 77-82 ◽  
Author(s):  
N. S. Oates ◽  
C. M. Perkins ◽  
M. R. Lee

1. Five normal subjects were studied under metabolic conditions on a controlled sodium and potassium intake. 2. Plasma and urine free dopamine concentrations were measured in these subjects before, during and after 5 days administration of fludrocortisone (0·2 mg twice daily). 3. Urine free dopamine showed a tendency to fall during the early phase of fludrocortisone administration and then rose towards normal. 4. In a patient with primary hyperaldosteronism there was no evidence of increased renal production of dopamine. Urine dopamine fell when plasma renin activity rose as a result of spironolactone administration (200 mg three times a day for 5 days). 5. If renal dopamine has a role in mineralocorticoid ‘escape’ then it may be permissive only. The mechanisms of control of dopamine production could include tubular sodium concentration, tubular chloride concentration and intrarenal renin activity.


PEDIATRICS ◽  
1971 ◽  
Vol 47 (3) ◽  
pp. 587-593
Author(s):  
George T. Bryan

Aldosterone secretion rate (ASR) was measured in 17 children during low, normal, and high dietary sodium intakes. Their ages varied from 3 months to 16 years; there were eight girls and nine boys. The average ASR with low, normal, and high sodium intakes were 236, 77, and 18 µg/ day respectively. The independent contribution of patient age, sex, sodium and potassium intake, and duration of fixed sodium intake was tested by least squares multiple regression analysis. The most important independent variable was sodium intake, although the sex and age of the patient were statistically significant variables. From this study it seems unlikely that precise control of all nutrients is necessary for evaluation of ASR if careful attention is paid to sodium intake.


2005 ◽  
Vol 56 (5) ◽  
pp. 427 ◽  
Author(s):  
David G. Masters ◽  
Allan J. Rintoul ◽  
Robyn A. Dynes ◽  
Kelly L. Pearce ◽  
Hayley C. Norman

Salinity is a problem facing many crop and livestock producers in southern Australia. One management option is to revegetate with salt-tolerant plants suitable for animal production. These plants are often halophytic shrubs containing up to 30% ash, predominantly as sodium, potassium, or chloride. This experiment examines the consequences of a high intake of sodium and potassium separately or together on feed intake, digestibility, liveweight change, and wool growth. Twelve groups of 6 weaner wethers were allocated to treatments according to a balanced 3 × 4 factorial design with 3 levels of added potassium (0, 0.38, and 0.77 mol/kg DM equivalent to 0, 15, and 30 g/kg DM) and 4 levels of added sodium (0, 0.87, 2.18, and 3.48 mol/kg DM, equivalent to 0, 20, 50, and 80 g/kg DM) as the chloride salts. The treatment diets were fed to sheep for 6 weeks. Increasing sodium in the diet significantly decreased feed intake, digestibility, liveweight gain, and wool growth either as a main effect or through an interaction with potassium. Organic matter intake was reduced from 1.35 kg at the lowest levels of sodium and potassium to 0.67 kg at the highest levels. Comparing the same 2 groups, liveweight gain was reduced from 144 to 0 g/day, organic matter digestibility from 59.1% to 57.3%, and wool growth from 1.21 to 1.04 mg/cm2.day. The response surfaces indicate that production was depressed even at the lower levels of sodium, whereas high potassium depressed intake, digestibility, and liveweight gain at high levels of sodium only. The interaction between sodium and potassium was always negative at high levels of sodium, indicating that manipulation of the proportions of the 2 elements is unlikely to provide benefits for animal production when total salt levels are high. Although wool growth was depressed at high sodium and potassium, the efficiency of wool growth increased from 10.0 to 15.4 g/kg organic matter intake when the lowest and highest levels of the sodium and potassium were compared. This result may present significant opportunities for the use of saline land to grow fine wool.


Nutrients ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3275 ◽  
Author(s):  
Bigina N.R. Ginos ◽  
Rik H.G. Olde Engberink

Globally, average dietary sodium intake is double the recommended amount, whereas potassium is often consumed in suboptimal amounts. High sodium diets are associated with increased cardiovascular and renal disease risk, while potassium may have protective properties. Consequently, patients at risk of cardiovascular and renal disease are urged to follow these recommendations, but dietary adherence is often low due to high sodium and low potassium content in processed foods. Adequate monitoring of intake is essential to guide dietary advice in clinical practice and can be used to investigate the relationship between intake and health outcomes. Daily sodium and potassium intake is often estimated with 24-h sodium and potassium excretion, but long-term balance studies demonstrate that this method lacks accuracy on an individual level. Dietary assessment tools and spot urine collections also exhibit poor performance when estimating individual sodium and potassium intake. Collection of multiple consecutive 24-h urines increases accuracy, but also patient burden. In this narrative review, we discuss current approaches to estimating dietary sodium and potassium intake. Additionally, we explore alternative methods that may improve test accuracy without increasing burden.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Paula Moliterno ◽  
Ramón Álvarez-Vaz ◽  
Matias Pécora ◽  
Leonella Luzardo ◽  
Luciana Borgarello ◽  
...  

Many public health policies in Latin America target an optimized sodium and potassium intake. The aims of this study were to assess the sodium and potassium intake using 24-hour urinary analysis and to study their association with blood pressure in a Uruguayan population cohort using cluster analysis. A total of 149 participants (aged 20–85 years) were included in the study, and office blood pressure, anthropometric measurements, biochemical parameters in the blood, and 24-hour urine samples were obtained. The overall mean sodium and potassium excretion was 152.9 ± 57.3 mmol/day (8.9 ± 3.4 g/day of salt) and 55.4 ± 19.6 mmol/day, respectively. The average office systolic/diastolic blood pressure was 124.6 ± 16.7/79.3 ± 9.9 mmHg. Three compact spherical clusters were defined in untreated participants based on predetermined attributes, including blood pressure, age, and sodium and potassium excretion. The major characteristics of the three clusters were (1) high systolic blood pressure and moderate sodium excretion, (2) moderate systolic blood pressure and very high sodium excretion, and (3) low systolic blood pressure and low sodium excretion. Participants in cluster three had systolic blood pressure values that were 23.9 mmHg (95% confidence interval: −29.5 to −1.84) lower than those in cluster one. Participants in cluster two had blood pressure levels similar to those in cluster one (P = 0.32) and worse metabolic profiles than those in cluster one and three (P < 0.05). None of the clusters showed high blood pressure levels and high sodium excretion. No linear association was found between blood pressure and urinary sodium excretion (r < 0.14; P > 0.47). An effect of sodium and potassium intake on blood pressure levels was not found at the population level using regression or cluster analysis.


Author(s):  
Conor Judge ◽  
Martin J O’Donnell ◽  
Graeme J Hankey ◽  
Sumathy Rangarajan ◽  
Siu Lim Chin ◽  
...  

Abstract Background Although low sodium intake (&lt;2g/day) and high potassium intake (&gt;3·5g/day) are proposed as public health interventions to reduce stroke risk, there is uncertainty about the benefit and feasibility of this combined recommendation on prevention of stroke and its subtypes. Methods We obtained random urine samples from 9,275 cases of acute first stroke and 9,726 matched controls (8,761 matched pairs for conditional analysis) from 27 countries and estimated the 24-hour sodium and potassium excretion, a surrogate for intake, using the Tanaka formula. Using multivariable conditional logistic regression, we determined the associations of estimated 24-hour urinary sodium and potassium excretion with stroke and its subtypes. Results The mean estimated 24-hour sodium and potassium urinary excretion was 3·29g/day and 1·57g/day, with 0·01% of participants having both low sodium (&lt;2·0g/day) and high potassium excretion (&gt;3·5g/day). There was a moderate positive correlation between sodium and potassium excretion (r=0·4435, P&lt;0.001) and between sodium excretion and blood pressure (P&lt;0.001). Compared with an estimated urinary sodium excretion of 2·8-3·5g/day (second quartile, reference), higher (&gt;4·26g/day) (OR 1.81;95%CI,1.65-2.00) and lower (&lt;2·8g/day) sodium excretion (OR 1.39;95%CI,1.26-1.53) were significantly associated with increased risk of stroke. The stroke risk associated with the highest quartile of sodium intake (sodium excretion &gt;4·26g/day) was significantly greater (P&lt;0.001) for intracerebral haemorrhage (ICH) (OR 2.38;95%CI,1.93-2.92) than for ischemic stroke (OR 1.67;95%CI,1.50-1.87), and greater for large vessel and small vessel ischemic stroke than for cardioembolic ischemic stroke. Urinary potassium was inversely and linearly associated with risk of stroke, and stronger for ischemic stroke than ICH (P=0.026). In an analysis of combined sodium and potassium excretion, the combination of high potassium intake (&gt;1·58g/day) and moderate sodium intake (2.8-3.5 g/day) was associated with the lowest risk of stroke. Conclusion The association of sodium intake and stroke is J-shaped, with high sodium intake a stronger risk factor for intracerebral haemorrhage than ischemic stroke. Our data suggest that moderate sodium intake – rather than low sodium intake – combined with high potassium intake may be associated with the lowest risk of stroke and expected to be a more feasible combined dietary target.


Author(s):  
T. A. Welton

An ultimate design goal for an improved electron microscope, aimed at biological applications, is the determination of the structure of complex bio-molecules. As a prototype of this class of problems, we propose to examine the possibility of reading DNA sequence by an imaginable instrument design. This problem ideally combines absolute importance and relative simplicity, in as much as the problem of enzyme structure seems to be a much more difficult one.The proposed technique involves the deposition on a thin graphite lamina of intact double helical DNA rods. If the structure can be maintained under vacuum conditions, we can then make use of the high degree of order to greatly reduce the work involved in discriminating between the four possible purine-pyrimidine arrangements in each base plane. The phosphorus atoms of the back bone form in projection (the helical axis being necessarily parallel to the substrate surface) two intertwined sinusoids. If these phosphorus atoms have been located up to a certain point on the molecule, we have available excellent information on the orientation of the base plane at that point, and can then locate in projection the key atoms for discrimination of the four alternatives.


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