Dependence of Urinary Prostaglandin E2 Excretion on Urinary Volume Rather than Solute Handling or Segmental Nephron Function in Man

1984 ◽  
Vol 67 (4) ◽  
pp. 413-420 ◽  
Author(s):  
Sming Kaojarern ◽  
Polavat Chennavasin ◽  
Ann Burdette ◽  
William B. Campbell ◽  
D. Craig Brater

1. Eight normal subjects underwent water loading alone and water loading plus 40 mg of frusemide IV, fluid intake ad libitum alone and fluid intake ad libitum plus frusemide, plus each of the preceding after pretreatment with indomethacin. 2. After frusemide administration, increases in urinary sodium excretion paralleled increases in urinary volume, and urinary prostaglandin E2 (PGE2) excretion correlated closely with sodium excretion (y = 1.03x −0.28; r = 0.940; P<.0001). 3. In the absence of the diuretic, urinary volume varied over a wide range with little change in sodium excretion. Again, urinary PGE2 excretion correlated with urinary sodium excretion (y = 0.12x + 0.05; r = 0.789; P<.002). However, the correlation differed markedly from that observed in the studies with frusemide. 4. Expressing urinary PGE2 excretion as a function of urinary volume for all of the studies resulted in a highly significant correlation (y = 10.7x −0.70; r = 0.975; P<.0001). 5. Multiple and stepwise regression analyses assessing the correlation of urinary PGE2 excretion with urinary flow rate and with indices of function of various nephron segments indicate that the correlation with urinary PGE2 could be predominantly accounted for by urinary volume. 6. We conclude that in the condition of this study in man, urinary PGE2 excretion is a correlate of urinary volume.

1987 ◽  
Vol 65 (12) ◽  
pp. 2428-2432 ◽  
Author(s):  
J. Michael Wyss ◽  
Wanida Sripairojthikoon ◽  
Suzanne Oparil

In previous experiments we have demonstrated that the renal nerves play a significant role in all genetic and (or) induced models of hypertension that we have studied. The current experiments extended this research by investigating the contribution of the renal nerves to hypertension in the Dahl NaCl-sensitive rat. This was investigated by assessing the effect of bilateral phenol renal denervation carried out prior to initiation of a high NaCl (8% NaCl) diet. In two separate studies, renal denervation did not affect systolic blood pressure in either Dahl NaCl-sensitive rats or their normotensive counterparts, Dahl NaCl-resistant rats. Further, denervation did not increase absolute urinary sodium excretion, percent urinary sodium excretion, urinary volume output, or food or water intake; nor did it differentially alter creatinine clearance or body weight. Denervation was verified at the termination of each study by a greater than 80% depletion of renal noradrenaline stores. These results indicate that the renal nerves do not provide a major contribution to hypertension in the Dahl NaCl-sensitive rat.


1986 ◽  
Vol 32 (3) ◽  
pp. 221-226 ◽  
Author(s):  
Suketa Yasunobu ◽  
Nishimura Keiko ◽  
Nakajima Hiroshi ◽  
Ueda Motoji ◽  
Okada Shojl

1993 ◽  
Vol 85 (4) ◽  
pp. 487-494 ◽  
Author(s):  
Chim C. Lang ◽  
Abdul R. Rahman ◽  
David J. K. Balfour ◽  
Allan D. Struthers

1. The renal effects of incremental doses of intravenously infused noradrenaline were evaluated in normal subjects during two different water loads, 5 ml/kg (n = 6) and 20 ml/kg (n = 9), producing conditions of euhydration and overhydration, respectively. 2. Noradrenaline infusion rates ranged from 0.015 to 0.075 μg min−1 kg−1. In the euhydrated subjects, noradrenaline caused a dose-dependent fall in urinary sodium excretion and an increase in urinary flow rate. During overhydration similar doses of noradrenaline caused a fall in urinary sodium excretion but a decrease in urinary flow rate. 3. Although there was no detectable change in glomerular filtration rate, a dose-dependent fall in effective renal plasma flow was observed in both hydration states during noradrenaline infusion. 4. Noradrenaline infusion was associated with a dose-dependent increase in proximal tubular sodium reabsorption as assessed by the lithium clearance method. Fractional reabsorption of sodium by the distal nephron was, however, unchanged by noradrenaline in both hydration states. 5. Plasma vasopressin concentration was unchanged by noradrenaline in euhydrated subjects. The renin-angiotensin-aldosterone axis was stimulated by noradrenaline in both euhydrated and overhydrated subjects. 6. Thus we conclude that plasma circulating noradrenaline has a dose-dependent antinatriuretic effect in man. The antinatriuretic effect of noradrenaline is mediated mainly at the proximal tubule in man. We have also shown that during overhydration, noradrenaline decreased urinary flow rate. In contrast, in euhydrated subjects, noradrenaline increased urinary flow rate with no accompanying changes in plasma vasopressin concentration, which suggests a direct effect of noradrenaline on the renal tubular permeability to water.


Author(s):  
Gianluigi Ardissino ◽  
Antonio Vergori ◽  
Cesare Vergori ◽  
Laura Martelli ◽  
Valeria Daccò ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaofu Du ◽  
Le Fang ◽  
Jianwei Xu ◽  
Xiangyu Chen ◽  
Yamin Bai ◽  
...  

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.


2021 ◽  
pp. 1-42
Author(s):  
Yi-Jie Wang ◽  
Kuo-Lioug Chien ◽  
Hsiu-Ching Hsu ◽  
Hung-Ju Lin ◽  
Ta-Chen Su ◽  
...  

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.


PLoS ONE ◽  
2019 ◽  
Vol 14 (12) ◽  
pp. e0227035 ◽  
Author(s):  
Esther Cuadrado-Soto ◽  
África Peral-Suarez ◽  
Elena Rodríguez-Rodríguez ◽  
Aránzazu Aparicio ◽  
Pedro Andrés ◽  
...  

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