Angiotensin II and Not Sodium Status is the Major Determinant of the Agonistic/Antagonistic Balance of Saralasin's Actions

1980 ◽  
Vol 59 (s6) ◽  
pp. 75s-78s ◽  
Author(s):  
R. Fagard ◽  
A. Amery ◽  
P. Lijnen
Keyword(s):  
Angiotensin Ii ◽  
Sodium Excretion ◽  
Sodium Intake ◽  
Plasma Renin ◽  
Urinary Sodium Excretion ◽  
Urinary Sodium ◽  
Plasma Angiotensin ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

1. To study which factors determine the balance between the antagonistic and agonistic effects of the angiotensin II analogue [Sar1,Ala8]-angiotensin II (saralasin) in man, saralasin was infused in subjects on a ‘normal’ sodium intake (group 1) during sodium restriction with appropriately elevated plasma angiotensin II levels (group 2) and in sodium-restricted subjects in whom plasma angiotensin II was suppressed by converting enzyme inhibition with captopril (group 3). 2. The action of saralasin was agonistic in group 3, antagonistic in group 2 and variable in group 1. 3. For groups 1 and 2 together the saralasin-induced changes of arterial pressure, of plasma aldosterone and of plasma renin were significantly related to control plasma angiotensin II but also to the 24 h urinary sodium excretion. When group 3 was included the changes remained significantly related to plasma angiotensin II but not to the urinary sodium excretion. 4. The results indicate that angiotensin II and not sodium status determines the agonistic/antagonistic balance of saralasin's actions.

Angiotensin II and Sodium as Determinants of the Agonistic-Antagonistic Balance of Saralasin's Actions

1981 ◽  
Vol 60 (4) ◽  
pp. 377-385 ◽  
Author(s):  
R. Fagard ◽  
A. Amery ◽  
P. Lijnen
Keyword(s):  
Angiotensin Ii ◽  
Arterial Pressure ◽  
Plasma Renin Activity ◽  
Plasma Renin ◽  
Plasma Aldosterone ◽  
Sodium Restriction ◽  
Plasma Angiotensin ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

1. To study which factors determine the balance between the antagonistic and agonistic effects of the angiotensin II analogue [Sar1,Ala8]angiotensin II (saralasin) in man, saralasin was infused in subjects on a ‘normal’ sodium intake (group 1) and during sodium restriction with appropriately elevated plasma angiotensin II levels (group 2), and in sodium-restricted subjects in whom plasma angiotensin II was suppressed by converting-enzyme inhibition with captopril (group 3). 2. The saralasin-induced increase of plasma aldosterone concentration in group 1 was different (P<0.005) from the decrease in group 2, whereas saralasin produced a significant increase of plasma aldosterone in group 3. For the three groups combined the changes of plasma aldosterone were significantly related to control angiotensin II levels, but not to the 24 h urinary sodium excretion. The data suggest that it is the rise of angiotensin II in response to the sodium restriction and not the sodium restriction per se that is associated with the antagonistic action of saralasin on the adrenal receptors. 3. On average mean intra-arterial pressure at 30 min was not affected by saralasin in group 1, had decreased in group 2 and increased (P<0.001) by 4.4 mmHg in group 3. Overall the changes of arterial pressure were significantly related to control angiotensin II, but not to the 24 h sodium excretion, suggesting that the angiotensin II levels predominantly determine the agonistic-antagonistic balance of saralasin's actions on arterial pressure. 4. Although saralasin did not affect plasma renin activity in group 1, plasma renin rose in group 2 and was reduced by 40% (P<0.001) in group 3. For the three groups together the changes of plasma renin activity were significantly related to the changes of mean arterial pressure both on single and multiple regression analyses. The changes of pressure ‘explain’, however, only a fraction of the changes of plasma renin; it is suggested that saralasin has an agonistic effect on the renal receptors involved in the direct suppression of renin by angiotensin II in low-sodium, low-angiotensin conditions and that an antagonistic effect may contribute to the saralasin-induced rise of renin during sodium restriction with appropriate angiotensin II levels.

Plasma Renin, Urinary Sodium Excretion and Vascular Disease

1974 ◽  
Vol 48 (s2) ◽  
pp. 127s-129s
Author(s):  
A. E. Doyle ◽  
K. G. Chua ◽  
S. Duffy ◽  
W. J. Louis
Keyword(s):  
Plasma Renin Activity ◽  
Urinary Excretion ◽  
Vascular Disease ◽  
Sodium Excretion ◽  
Mild Hypertension ◽  
Sodium Intake ◽  
Plasma Renin ◽  
Urinary Sodium Excretion ◽  
Urinary Sodium ◽  
Renin Activity

1. Urinary sodium excretion and plasma renin activity have been measured in a group of persons with untreated mild hypertension and in a control normotensive group. 2. Preliminary analyses of the data indicate that the daily sodium excretion was significantly higher in the hypertensive group but the plasma renin activity did not correlate significantly with the urinary excretion of sodium. 3. These findings suggest that sodium intake was significantly greater in a population with mild hypertension than in a comparable normotensive group.

Forebrain-mediated adaptations to myocardial infarction in the rat

2002 ◽  
Vol 282 (5) ◽  
pp. H1898-H1906 ◽  
Author(s):  
Joseph Francis ◽  
Shun-Guang Wei ◽  
Robert M. Weiss ◽  
Terry Beltz ◽  
Alan Kim Johnson ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Sodium Excretion ◽  
Sodium Intake ◽  
Third Ventricle ◽  
Critical Role ◽  
Urine Volume ◽  
Plasma Renin ◽  
Urinary Sodium Excretion ◽  
Urinary Sodium ◽  
Neurohumoral Regulation

Recent studies suggest that the forebrain contributes to the circulatory derangements leading to heart failure after myocardial injury. We tested that hypothesis by examining the effect of myocardial infarction (MI) or sham MI (MI-s) on neurohumoral regulation in rats with prior anteroventral (AV) third ventricle lesion (AV3V-x) or sham lesion (AV3V-s). AV3V-s/MI rats had higher sodium intake, lower urine volume, and lower urinary sodium excretion than AV3V-s/MI-s rats. AV3V-x/MI rats had lower sodium intake and higher urine volume than AV3V-s/MI or AV3V-s/MI-s rats and urinary sodium excretion comparable to AV3V-s/MI-s rats. AV3V-x had no effect on baseline plasma renin activity (PRA). One week after MI, PRA had increased in AV3V-s but decreased in AV3V-x rats. AV3V-x reduced renal sympathetic nerve activity in MI and MI-s rats. AV3V-x improved baroreflex function in MI rats but diminished it in MI-s rats. Survival beyond 2 wk was lower in the AV3V-x/MI rats than in all other groups. These results confirm a critical role for the forebrain in the neurohumoral adjustments to MI.

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

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.

Abstract P403: Seasonal Variation in the Daily Urinary Sodium Excretion in Outpatients From the Northern Japan

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Tomoko Hashimoto
Keyword(s):  
Seasonal Variation ◽  
Sodium Excretion ◽  
Salt Intake ◽  
Sodium Intake ◽  
Urinary Sodium Excretion ◽  
Urinary Sodium ◽  
Reliable Estimate ◽  
Significant Difference ◽  
The Mean ◽  
Northern Japan

Although the daily urinary sodium excretion (UNaV) is considered to provide the most reliable estimate of the daily sodium intake, it may be affected by salt loss due to sweating in summer. However, theseasonal variation in the daily UNaV associated with a normal lifestyle is unknown. This study was performed in 348 outpatients from the Morioka region during three seasons: summer(summer 1), winter, and the following summer (summer 2). The daily UNaV (g salt/day) was estimated by the second morning urine method three times during each season. Seasonal variation was defined as a significant trend across the three seasons together with a significant difference between winter and both summers. In women, the daily UNaV was higher in winter (11.8±3.0 g salt/day) than in summer 1 (11.2±2.9g salt/day) or summer 2 (11.0±2.9 g salt/day). In contrast, there was no marked seasonal variation in men. An analysis stratified by age (4 quartiles) identified seasonal variation in the older 2 quartiles of women (aged ≧68 years). In these women, the mean seasonal difference in the daily UNaV was 0.9 g of salt/day for both winter vs. summer 1 and winter vs. summer 2, while it was 0.1-0.8 g of salt/day in the other groups. Seasonal variation in the daily UNaV only occurred in older female patients and was relatively small. This is evidence for restricting salt intake throughout the year and should reassure patients who are anxious about salt loss due to sweating in summer.

scholarly journals Urine Spot Samples Can Be Used to Estimate 24-Hour Urinary Sodium Excretion in Children

2018 ◽  
Vol 148 (12) ◽  
pp. 1946-1953 ◽  
Author(s):  
Magali Rios-Leyvraz ◽  
Pascal Bovet ◽  
René Tabin ◽  
Bernard Genin ◽  
Michel Russo ◽  
...  
Keyword(s):  
Sodium Excretion ◽  
Salt Intake ◽  
Sodium Intake ◽  
Population Level ◽  
Urinary Sodium Excretion ◽  
Cross Sectional Study ◽  
Urinary Sodium ◽  
Cross Sectional ◽  
High Sodium ◽  
Individual Level

ABSTRACT Background The gold standard to assess salt intake is 24-h urine collections. Use of a urine spot sample can be a simpler alternative, especially when the goal is to assess sodium intake at the population level. Several equations to estimate 24-h urinary sodium excretion from urine spot samples have been tested in adults, but not in children. Objective The objective of this study was to assess the ability of several equations and urine spot samples to estimate 24-h urinary sodium excretion in children. Methods A cross-sectional study of children between 6 and 16 y of age was conducted. Each child collected one 24-h urine sample and 3 timed urine spot samples, i.e., evening (last void before going to bed), overnight (first void in the morning), and morning (second void in the morning). Eight equations (i.e., Kawasaki, Tanaka, Remer, Mage, Brown with and without potassium, Toft, and Meng) were used to estimate 24-h urinary sodium excretion. The estimates from the different spot samples and equations were compared with the measured excretion through the use of several statistics. Results Among the 101 children recruited, 86 had a complete 24-h urine collection and were included in the analysis (mean age: 10.5 y). The mean measured 24-h urinary sodium excretion was 2.5 g (range: 0.8–6.4 g). The different spot samples and equations provided highly heterogeneous estimates of the 24-h urinary sodium excretion. The overnight spot samples with the Tanaka and Brown equations provided the most accurate estimates (mean bias: −0.20 to −0.12 g; correlation: 0.48–0.53; precision: 69.7–76.5%; sensitivity: 76.9–81.6%; specificity: 66.7%; and misclassification: 23.0–27.7%). The other equations, irrespective of the timing of the spot, provided less accurate estimates. Conclusions Urine spot samples, with selected equations, might provide accurate estimates of the 24-h sodium excretion in children at a population level. At an individual level, they could be used to identify children with high sodium excretion. This study was registered at clinicaltrials.gov as NCT02900261.

Effects of hypoproteinemia on renal hemodynamics, arterial pressure, and fluid volume

1987 ◽  
Vol 252 (1) ◽  
pp. F91-F98
Author(s):  
R. D. Manning
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Sodium Excretion ◽  
Sodium Intake ◽  
Renal Plasma Flow ◽  
Urinary Sodium Excretion ◽  
Renal Hemodynamics ◽  
Fluid Volume ◽  
Urinary Sodium ◽  
Plasma Aldosterone Concentration

The effects of long-term hypoproteinemia on renal hemodynamics, arterial pressure, and fluid volume were studied in eight conscious dogs over a 34-day period. Plasma protein concentration (PPC) was decreased by daily plasmapheresis, and the effects of decreasing and increasing sodium intake were measured. By the 12th day of plasmapheresis, during which sodium intake was 30 meq/day, PPC had decreased to 2.5 g/dl from a control value of 7.2 g/dl, mean arterial pressure had decreased to 78% of control, glomerular filtration rate (GFR) was 75.2% of control, and urinary sodium excretion was decreased. By day 18 of plasmapheresis, estimated renal plasma flow (ERPF) was decreased to 60% of control due to the decreased arterial pressure and an increase in renal vascular resistance. Also, plasma renin activity and plasma aldosterone concentration were both increased, and the relationship between mean arterial pressure and urinary sodium excretion was distinctly shifted to the left along the arterial pressure axis. In contradistinction to acute experiments, chronic hypoproteinemia results in decreases in GFR, ERPF, and urinary sodium excretion and has marked effects on both fluid volume and arterial pressure regulation.

scholarly journals Vascular Type 1A Angiotensin II Receptors Control BP by Regulating Renal Blood Flow and Urinary Sodium Excretion

2015 ◽  
Vol 26 (12) ◽  
pp. 2953-2962 ◽  
Author(s):  
Matthew A. Sparks ◽  
Johannes Stegbauer ◽  
Daian Chen ◽  
Jose A. Gomez ◽  
Robert C. Griffiths ◽  
...  
Keyword(s):  
Blood Flow ◽  
Angiotensin Ii ◽  
Renal Blood Flow ◽  
Sodium Excretion ◽  
Urinary Sodium Excretion ◽  
Urinary Sodium ◽  
Angiotensin Ii Receptors ◽  
Vascular Type
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