Role of renal nerves in maintaining sodium balance in unrestrained conscious rats

1985 ◽  
Vol 249 (6) ◽  
pp. F819-F826 ◽  
Author(s):  
E. Fernandez-Repollet ◽  
C. R. Silva-Netto ◽  
R. E. Colindres ◽  
C. W. Gottschalk
Keyword(s):  
Blood Pressure ◽  
Renal Denervation ◽  
Sodium Intake ◽  
Plasma Renin ◽  
Dietary Sodium ◽  
Sodium Balance ◽  
Renal Nerves ◽  
Sodium Restriction ◽  
Low Sodium ◽  
Dietary Sodium Restriction

This study was designed to investigate the effects of bilateral renal denervation on sodium and water balance, the renin-angiotensin system, and systemic blood pressure in unrestrained conscious rats maintained on a normal- or low-sodium diet. Renal denervation was proven by chemical and functional tests. Both bilaterally denervated rats (n = 18) and sham-denervated rats (n = 15) maintained positive sodium balance while on a normal sodium intake. Both groups were in negative sodium balance for 1 day after dietary sodium restriction was instituted but were in positive sodium balance for the following 9 days. Systolic blood pressure was higher in sham-denervated (115 +/- 3 mmHg) than in denervated rats (102 +/- 3 mmHg) while on a normal diet (P less than 0.05) and remained so during sodium restriction. Plasma renin concentration (PRC) and plasma aldosterone concentration (PAC) were significantly diminished in the denervated rats during normal sodium intake (P less than 0.05). After dietary sodium restriction, PRC increased in both groups but remained significantly lower in the denervated rats (P less than 0.05). Following dietary sodium restriction, PAC also increased significantly to levels that were similar in both groups of rats. These results demonstrate that awake unrestrained growing rats can maintain positive sodium balance on a low sodium intake even in the absence of the renal nerves. However, efferent renal nerve activity influenced plasma renin activity in these animals.

Sodium intake and the effects of isoproterenol and exercise on plasma renin in man

1978 ◽  
Vol 45 (6) ◽  
pp. 870-874 ◽  
Author(s):  
F. H. Leenen ◽  
P. Boer ◽  
G. G. Geyskes
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Diastolic Blood Pressure ◽  
Sodium Intake ◽  
Plasma Renin ◽  
Dynamic Exercise ◽  
Dietary Sodium ◽  
Sodium Restriction ◽  
Dietary Sodium Restriction

Changes in heart rate, blood pressure, and plasma renin activity (PRA) were assessed during infusion of increasing doses of isoproterenol and during increasing work loads of dynamic exercise in five normal young men. Studies were performed at three levels of dietary sodium restriction: normal, moderately, and more severely restricted. Isoproterenol induced the expected dose-related increases in heart rate, systolic blood pressure, and PRA and decreases in diastolic blood pressure. Changes in dietary sodium intake affected these changes only to a minor degree. Dynamic exercise also induced the expected work-load-related increases in heart rate, systolic blood pressure, and PRA and decreases in diastolic blood pressure. Also these changes were not significantly affected by changes in dietary sodium intake. Apparently dietary sodium restriction does not sensitize the renin-releasing mechanisms to sympathetic stimulation.

Renal nerves in renal adaptation to dietary sodium restriction

1983 ◽  
Vol 245 (3) ◽  
pp. F322-F328 ◽  
Author(s):  
G. F. DiBona ◽  
L. L. Sawin
Keyword(s):  
Renal Denervation ◽  
Dietary Sodium ◽  
Sodium Balance ◽  
Renal Nerves ◽  
Sodium Restriction ◽  
Sodium Diet ◽  
Low Sodium Diet ◽  
Low Sodium ◽  
Body Sodium ◽  
Renal Adaptation

To assess the physiologic importance of the renal nerves in the renal mechanisms for the maintenance of body sodium balance, renal adaptation to normal and low sodium diet was evaluated in conscious Sprague-Dawley male rats before and 8 days after recovery from bilateral surgical-pharmacological renal denervation. Renal denervation was confirmed in every rat at the end of the study by absence of renal vasoconstriction to splanchnic nerve stimulation and loss of renal tissue norepinephrine content. Daily sodium balance, defined as the difference between dietary sodium intake and urinary sodium excretion, was positive with the normal sodium diet before and after bilateral renal denervation. Prior to bilateral renal denervation, changing to the low sodium diet was associated with a diminishingly negative sodium balance for 3 days that became progressively positive thereafter. After bilateral renal denervation, changing to the low sodium diet was associated with a continuous and progressively negative sodium balance. We conclude that intact renal innervation is required for normal renal sodium conservation and maintenance of body sodium balance during dietary sodium restriction.

Temporal pattern of renin and aldosterone secretion in men: effects of sodium balance

1992 ◽  
Vol 262 (5) ◽  
pp. F871-F877 ◽  
Author(s):  
W. V. Vieweg ◽  
J. D. Veldhuis ◽  
R. M. Carey
Keyword(s):  
Sodium Intake ◽  
Time Lag ◽  
Plasma Renin ◽  
Plasma Aldosterone ◽  
Dietary Sodium ◽  
Sodium Balance ◽  
Sodium Restriction ◽  
Aldosterone Secretion ◽  
Plasma Aldosterone Concentration ◽  
Low Sodium

To investigate the pulsatile nature of basal and stimulated renin and aldosterone secretion, we sampled blood for plasma renin activity (PRA) and plasma aldosterone concentration at 10-min intervals for 24 h in nine normal supine human male subjects after equilibration in high- and low-sodium balance states. We evaluated serial hormonal measures by a quantitative waveform-independent deconvolution technique designed to compute the number, amplitude, and mass of underlying secretory bursts and simultaneously to estimate the presence and extent of basal secretion. For both PRA and aldosterone: 1) burstlike release accounted for greater than or equal to 60% of total secretion and tonic release for less than 40%; 2) there was an 80- to 85-min interpulse interval unchanged by sodium intake; 3) sodium restriction engendered an increase in plasma hormone concentrations by increasing the amount and maximal rate of hormone secreted per burst; 4) low dietary sodium also induced increases in basal hormone secretory rates, suggesting that there may be two regulatory processes driving renin and aldosterone secretion; and 5) PRA was significantly coupled to plasma aldosterone concentration by a 0-, 10-, or 20-min aldosterone lag time in both high- and low-sodium balance. We conclude that both renin and aldosterone are released via a predominantly burstlike mode of secretion; PRA and plasma aldosterone concentrations are positively coupled by a short time lag (0-20 min); and sodium restriction achieves an increase in mean PRA and plasma aldosterone concentration by selective amplitude enhancement of individual hormone secretory bursts and by increased tonic (interburst) basal secretory rates.

scholarly journals The Effects of Short-Term Changes in Sodium Intake on Plasma Marinobufagenin Levels in Patients with Primary Salt-Sensitive and Salt-Insensitive Hypertension

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1502
Author(s):  
Katarzyna Łabno-Kirszniok ◽  
Agata Kujawa-Szewieczek ◽  
Andrzej Wiecek ◽  
Grzegorz Piecha
Keyword(s):  
Blood Pressure ◽  
Diastolic Blood Pressure ◽  
Sodium Intake ◽  
Left Ventricular ◽  
Primary Hypertension ◽  
Dietary Sodium ◽  
Sodium Restriction ◽  
Short Term ◽  
Salt Loading ◽  
Dietary Sodium Restriction

Increased marinobufagenin (MBG) synthesis has been suggested in response to high dietary salt intake. The aim of this study was to determine the effects of short-term changes in sodium intake on plasma MBG levels in patients with primary salt-sensitive and salt-insensitive hypertension. In total, 51 patients with primary hypertension were evaluated during acute sodium restriction and sodium loading. Plasma or serum concentrations of MBG, natriuretic pro-peptides, aldosterone, sodium, potassium, as well as hematocrit (Hct) value, plasma renin activity (PRA) and urinary sodium and potassium excretion were measured. Ambulatory blood pressure monitoring (ABPM) and echocardiography were performed at baseline. In salt-sensitive patients with primary hypertension plasma MBG correlated positively with diastolic blood pressure (ABPM) and serum NT-proANP concentration at baseline and with serum NT-proANP concentration after dietary sodium restriction. In this subgroup plasma MBG concentration decreased during sodium restriction, and a parallel increase of PRA was observed. Acute salt loading further decreased plasma MBG concentration in salt-sensitive subjects in contrast to salt insensitive patients. No correlation was found between plasma MBG concentration and left ventricular mass index. In conclusion, in salt-sensitive hypertensive patients plasma MBG concentration correlates with 24-h diastolic blood pressure and dietary sodium restriction reduces plasma MBG levels. Decreased MBG secretion in response to acute salt loading may play an important role in the pathogenesis of salt sensitivity.

Development of two-kidney Goldblatt hypertension in rats under dietary sodium restriction

1980 ◽  
Vol 238 (6) ◽  
pp. H889-H894 ◽  
Author(s):  
H. Munoz-Ramirez ◽  
R. E. Chatelain ◽  
F. M. Bumpus ◽  
P. A. Khairallah
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Plasma Renin ◽  
Renin Activity ◽  
Dietary Sodium ◽  
Sodium Restriction ◽  
Sodium Diet ◽  
Low Sodium Diet ◽  
Low Sodium ◽  
Goldblatt Hypertension

In Sprague-Dawley rats with unilateral renal artery stenosis and an intact contralateral kidney, administration of a low-sodium diet did not prevent the development of hypertension. Despite an elevated blood pressure, hyponatremia, marked activation of the renin-angiotensin system, and increased hematocrit values, only 10% of the rats showed lesions of malignant hypertension. Systolic blood pressures of one- and two-kidney sham-operated rats fed a low-sodium diet were significantly higher than that of normotensive controls fed a normal diet. Uninephrectomy did not reduce plasma renin activity. The low-sodium diet increased plasma renin activity to about the same level in one- and two-kidney normotensive rats. However, the increase in plasma renin activity elicited by dietary sodium restriction was markedly less in one-kidney Goldblatt hypertension. Systolic blood pressure reached similar levels in one- and two-kidney Goldblatt hypertensive rats fed a low-sodium diet. These data indicate that a decrease in sodium intake does not prevent the development of two-kidney Goldblatt hypertension.

Adrenergic control of renin during dietary sodium deprivation in conscious dogs

1989 ◽  
Vol 256 (6) ◽  
pp. E863-E871 ◽  
Author(s):  
H. Hisa ◽  
Y. H. Chen ◽  
K. J. Radke ◽  
J. L. Izzo ◽  
C. D. Sladek ◽  
...  
Keyword(s):  
Sodium Intake ◽  
Conscious Dogs ◽  
Dietary Sodium ◽  
Sodium Restriction ◽  
Adrenergic Stimulation ◽  
Sodium Diet ◽  
Low Sodium Diet ◽  
Low Sodium ◽  
Dietary Sodium Restriction

These experiments evaluated the contribution of alpha- and beta-adrenergic stimulation to plasma renin activity (PRA) during early and long-term dietary sodium restriction, compared with normal sodium intake. Uninephrectomized conscious dogs with catheters in the aorta, vena cava, and remaining renal artery were studied during normal sodium diet (approximately 70 meq/day), after 2-3 days of low-sodium diet (5-7 meq/day), and after greater than or equal to 2 wk of low-sodium diet. Direct renal arterial (ira) infusion of phenoxybenzamine plus propranolol decreased PRA by similar proportions (39-48%) during all three states of dietary sodium intake. The PRA achieved after adrenergic blockade remained higher (P less than 0.05) during early and long-term sodium restriction than during normal sodium intake. The effect on PRA of ira infusion of propranolol alone was not different from that of phenoxybenzamine plus propranolol during normal or low-sodium diet, and the magnitude of decrease in PRA during low-sodium diet was the same whether propranolol (1 microgram.kg-1.min-1) was infused ira or intravenously. In summary, beta-adrenergic stimulation accounts for similar proportions of PRA during early and long-term dietary sodium restriction and during normal sodium intake. Renal alpha-adrenoceptors appear to play little or no role in control of PRA under these conditions.

scholarly journals Dietary Sodium Restriction Increases the Risk of Misinterpreting Mild Cases of Primary Aldosteronism

2016 ◽  
Vol 101 (11) ◽  
pp. 3989-3996 ◽  
Author(s):  
Rene Baudrand ◽  
Francisco J. Guarda ◽  
Jasmine Torrey ◽  
Gordon Williams ◽  
Anand Vaidya
Keyword(s):  
Primary Aldosteronism ◽  
Sodium Intake ◽  
Plasma Renin ◽  
Dietary Sodium ◽  
Sodium Restriction ◽  
Positive Screen ◽  
Serum Aldosterone ◽  
Optimal Screening ◽  
Dietary Sodium Restriction ◽  
Aldosterone To Renin Ratio

Context: The aldosterone to renin ratio (ARR) is recommended to screen for primary aldosteronism (PA). Objective: To evaluate whether dietary sodium restriction results in misinterpretation of PA screening. Participants: Untreated hypertensives with ARR more than 20 on a high dietary sodium intake (HS) were also evaluated on a low dietary sodium intake (LS) (n = 241). Positive screening for PA was defined as: plasma renin activity (PRA) less than or equal to 1.0 ng/mL · h with serum aldosterone more than or equal to 6 ng/dL. PA was confirmed by a 24-hour urinary aldosterone excretion more than or equal to 12 mcg with urinary sodium more than 200 mmol. Results: Only 33% (79/241) of participants with an ARR more than 20 had a positive PA screen on HS. On LS, 56% (44/79) of these participants no longer met criteria for positive PA screening. When compared with participants with positive PA screening on both diets, participants with a positive screen on HS but negative on LS exhibited a significantly higher PRA on both diets. Remarkably, of the 48/79 participants who had PA confirmed, 52% had negative PA screening on LS. The distinguishing feature of these participants with “discordant” screening results was a larger rise in PRA on LS resulting in normalization of the ARR and higher Caucasian race prevalence. Conclusions: Sodium restriction is recommended in hypertension; however, it can significantly raise PRA, normalize the ARR, and result in false interpretation of PA screening. Milder phenotypes of PA, where PRA is not as suppressed, are most susceptible to dietary sodium influences on renin and ARR. Optimal screening for PA should occur under conditions of HS.

Effects of dietary sodium restriction and posture on plasma levels of atrial natriuretic peptide, aldosterone and free aldosterone in normal human pregnancy

1990 ◽  
Vol 124 (3) ◽  
pp. 507-513 ◽  
Author(s):  
E. A. P. Steegers ◽  
Th. J. Benraad ◽  
H. W. Jongsma ◽  
A. C. I. T. L. Tan ◽  
P. R. Hein
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Sodium Intake ◽  
Plasma Concentrations ◽  
Dietary Sodium ◽  
Sitting Position ◽  
Sodium Restriction ◽  
Lateral Tilt ◽  
Low Sodium ◽  
Dietary Sodium Restriction

ABSTRACT The effects of dietary sodium restriction and posture on plasma concentrations of atrial natriuretic peptide (ANP), aldosterone and free aldosterone were investigated in ten women between weeks 29 and 33 of normal pregnancy. Hormone levels were studied during unrestricted sodium intake and on day 6 of a low sodium diet. On both occasions venous blood was obtained in the sitting as well as in the left lateral tilt position. Plasma concentrations of ANP during the unrestricted sodium intake were not raised compared with control values in healthy non-pregnant females. Recovery experiments showed no differences in the degradation of ANP in blood from pregnant and non-pregnant women. Plasma concentrations of ANP significantly decreased (by 32%) in response to the low sodium regime in both positions. Concentrations of aldosterone and free aldosterone (in women in the sitting position) increased twofold after sodium restriction. Mean values of ANP were higher in women in the left lateral tilt position that in those in the sitting position, but the difference was not significant. Concentrations of aldosterone and free aldosterone were significantly lower (by around 30%) in women in the left lateral tilt position compared with those in the sitting posture. Journal of Endocrinology (1990) 124, 507–513

Prevention of hypertension and maintenance of normotension in spontaneously hypertensive rats is dependent on continuous severe dietary sodium restriction

1987 ◽  
Vol 65 (4) ◽  
pp. 573-578 ◽  
Author(s):  
Esther A. Wilczynski ◽  
Frans H. H. Leenen
Keyword(s):  
Blood Pressure ◽  
Sympathetic Activity ◽  
Spontaneously Hypertensive Rats ◽  
Sodium Intake ◽  
Dietary Sodium ◽  
Sodium Restriction ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Ganglionic Blockade ◽  
Dietary Sodium Restriction

Spontaneously hypertensive rats were placed on a very low (9 μmol/g) or control (101 μmol/g) sodium diet at birth or 4 weeks of age. These diets were continued to 16 weeks of age, or at 10 weeks were increased from 9 to 26 or 101 μmol/g. Sodium restriction initiated up to 4 weeks of age and continued to 16 weeks of age severely retarded growth, prevented the development of hypertension, and reduced effective sympathetic activity as assessed by the response of blood pressure to ganglionic blockade. Only a small increase in sodium intake at 10 weeks of age (to 26 μmol/g or more) resulted in a marked increase in growth rate, an elevation of blood pressure, and a return of the response to ganglionic blockade towards normal. These data indicate that very severe sodium restriction must be continuous to maintain decreased sympathetic activity and normal blood pressure in spontaneously hypertensive rats. It appears that severe dietary sodium restriction suppresses one or more of the mechanisms involved in normal growth and development of hypertension in spontaneously hypertensive rats, but these mechanisms may still proceed once the sodium intake is increased.

Dietary sodium restriction and blood pressure response to sympathetic blockade in young versus adolescent spontaneously hypertensive rats

1990 ◽  
Vol 68 (1) ◽  
pp. 46-50 ◽  
Author(s):  
Frans H. H. Leenen ◽  
Giannoula Klement
Keyword(s):  
Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Sodium Intake ◽  
Blood Pressure Response ◽  
Dietary Sodium ◽  
Sympathetic Blockade ◽  
Sodium Restriction ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Dietary Sodium Restriction

The effects of dietary sodium restriction on the maintenance of blood pressure (BP) by sympathetic tone were evaluated in young versus more mature spontaneously hypertensive rats (SHR) and Wistar–Kyoto rats (WKY). Sympathetic activity was assessed by BP responses to α1-receptor blockade (prazosin), central inhibition of sympathetic outflow (clonidine), and by ganglionic blockade (hexamethonium). On regular sodium intake, SHR showed elevated BP and increased BP responses to sympathetic blockade at both 10 and 16 weeks of age. Sodium restriction to 9 or 17 μmol Na+/g food prevented or blunted development of hypertension in SHR when started at 4 weeks of age but did not affect BP when started at 10 weeks of age. Sodium restriction initiated in young SHR also prevented development of increased BP responses to sympathetic blockade. However, sodium restriction in more mature SHR did not decrease the increased BP responses to sympathetic blockade. We conclude that prevention of development of sympathetic hyperactivity in young SHR represents a major mechanism in the antihypertensive effect of sodium restriction in young SHR.Key words: dietary sodium, blood pressure, spontaneously hypertensive rats, age, sympathetic blockade.

Sign in / Sign up

Export Citation Format

Share Document