Effects of Nifedipine during Low, Normal and High Intakes of Sodium in Patients with Essential Hypertension

1982 ◽  
Vol 63 (s8) ◽  
pp. 447s-450s ◽  
Author(s):  
Gloria Valdés ◽  
M. Eugenia Soto ◽  
Hector R. Croxatto ◽  
Teresa Bellolio ◽  
Ramón Corbalán ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Essential Hypertension ◽  
Sodium Intake ◽  
Plasma Renin ◽  
Hypotensive Effect ◽  
Sodium Balance ◽  
Hypotensive Action ◽  
High Sodium ◽  
High Sodium Intake ◽  
Low Sodium Diet

1. Nifedipine (20 mg) was given by mouth to seven patients with moderate essential hypertension receiving a low, normal or high sodium intake. The drug produced an important hypotensive effect. Normal sodium intake enhanced the hypotensive action of the drug compared with that during the low and high sodium regimens. Blood pressure remained significantly lower 3 h after drug ingestion. 2. Increases in heart rate and plasma renin activity under all conditions reflected enhanced adrenergic activity. 3. A short-term natriuresis followed nifedipine ingestion in spite of increased aldosterone excretion during the low sodium diet and a decrease in urinary kallikrein during the low and high sodium diets. 4. Nifedipine increased urinary volume only during the high sodium intake. 5. Apart from vasodilatation, nifedipine induces important changes in neurogenic, renal and adrenal mechanisms that regulate blood pressure homoeostasis. Different conditions of sodium balance modulate most of these effects.

scholarly journals Correlation of Salt Sensitivity, Plasma Renin Activity and Aldosterone in Hypertensive Patients

2017 ◽  
Vol 18 (s1) ◽  
pp. 55-60
Author(s):  
Nebojsa Tasic ◽  
Danijela Tasic ◽  
Dalibor Dragisic ◽  
Miroslav Mitrovic
Keyword(s):  
Blood Pressure ◽  
Essential Hypertension ◽  
Salt Intake ◽  
Plasma Renin ◽  
Salt Loading ◽  
High Sodium ◽  
Sodium Diet ◽  
Low Sodium Diet ◽  
Low Sodium ◽  
Resistant Group

Abstract Plasma-renin values vary in normotensive and hypertensive populations. Some studies consider renin to be a key factor in the aetiology of hypertension, but other studies note that renin is an important factor in cardiovascular homeostasis and functions more as a growth factor than as a pressor hormone. The aim of this study was to assess the PRA and aldosterone values under different salt intake regimes in patients with essential hypertension. The study group consisted of 50 untreated patients (27 women and 23 men; average age 42±9,2 yrs.; average BMI 27,91±4,6 kg/m2) with essential hypertension. All patients were put on a high-sodium diet (200 mmol NaCl per day) for one week after a week on a low-sodium diet (20 mmol NaCl per day). Sodium sensitivity (SS) was defined as a 10-mmHg increase in the mean blood pressure at the end of the high- vs. the low-sodium diet. The SS group consisted of 26 patients, and the sodiuminsensitive group consisted of 24 patients. The PRA and aldosterone levels were determined in 12 patients. PRA values in the SS group during rest were significantly lower compared with the salt-resistant group during all regimes of salt intake (F=10,56, p=0,0012). Salt loading in SS patients causes a significant decrease in PRA (in rest and effort) values in comparison to values during a low salt intake regime (rest: t=4,49, p<0,001; effort: t=3,45, p<0,01). The PRA values in the salt-resistant group did not vary significantly under the different salt intake regimes. The aldosterone values followed the pattern of the PRA values. It is necessary to distinguish investigations on salt intake effects based on incidence and value of blood pressure and investigations on salt restriction’s effects on of blood pressure levels (i.e., non-pharmacological hypertension therapy).

Renal and cardiac oxidative/nitrosative stress in salt-loaded pregnant rat

2007 ◽  
Vol 293 (4) ◽  
pp. R1657-R1665 ◽  
Author(s):  
Annie Beauséjour ◽  
Véronique Houde ◽  
Karine Bibeau ◽  
Rébecca Gaudet ◽  
Jean St-Louis ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Nitrosative Stress ◽  
Gestational Hypertension ◽  
Sodium Intake ◽  
Pregnant Rats ◽  
High Sodium ◽  
High Sodium Intake ◽  
Arterial Blood ◽  
Cardiac Ventricle

Sodium supplementation given for 1 wk to nonpregnant rats induces changes that are adequate to maintain renal and circulatory homeostasis as well as arterial blood pressure. However, in pregnant rats, proteinuria, fetal growth restriction, and placental oxidative stress are observed. Moreover, the decrease in blood pressure and expansion of circulatory volume, normally associated with pregnancy, are prevented by high-sodium intake. We hypothesized that, in these pregnant rats, a loss of the balance between prooxidation and antioxidation, particularly in kidneys and heart, disturbs the normal course of pregnancy and leads to manifestations such as gestational hypertension. We thus investigated the presence of oxidative/nitrosative stress in heart and kidneys following high-sodium intake in pregnant rats. Markers of this stress [8-isoprostaglandin F2α (8-iso-PGF2α) and nitrotyrosine], producer of nitric oxide [nitric oxide synthases (NOSs)], and antioxidants [superoxide dismutase (SOD) and catalase] were measured. Then, molecules (Na+-K+-ATPase and aconitase) or process [apoptosis (Bax and Bcl-2), inflammation (monocyte chemoattractant protein-1, connective tissue growth factor, and TNF-α)] susceptible to free radicals was determined. In kidneys from pregnant rats on 1.8% NaCl-water, NOSs, apoptotic index, and nitrotyrosine expression were increased, whereas Na+-K+-ATPase mRNA and activity were decreased. In the left cardiac ventricle of these rats, heightened nitrotyrosine, 8-iso-PGF2α, and catalase activity together with reduced endothelial NOS protein expression and SOD and aconitase activities were observed. These findings suggest that oxidative/nitrosative stress in kidney and left cardiac ventricle destabilizes the normal course of pregnancy and could lead to gestational hypertension.

High-sodium intake prevents pregnancy-induced decrease of blood pressure in the rat

2003 ◽  
Vol 285 (1) ◽  
pp. H375-H383 ◽  
Author(s):  
Annie Beauséjour ◽  
Karine Auger ◽  
Jean St-Louis ◽  
Michèle Brochu
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Sodium Intake ◽  
Plasma Sodium ◽  
Mrna Levels ◽  
Sprague Dawley ◽  
Pregnant Rats ◽  
High Sodium ◽  
High Sodium Intake ◽  
The Impact

Despite an increase of circulatory volume and of renin-angiotensin-aldosterone system (RAAS) activity, pregnancy is paradoxically accompanied by a decrease in blood pressure. We have reported that the decrease in blood pressure was maintained in pregnant rats despite overactivation of RAAS following reduction in sodium intake. The purpose of this study was to evaluate the impact of the opposite condition, e.g., decreased activation of RAAS during pregnancy in the rat. To do so, 0.9% or 1.8% NaCl in drinking water was given to nonpregnant and pregnant Sprague-Dawley rats for 7 days (last week of gestation). Increased sodium intakes (between 10- and 20-fold) produced reduction of plasma renin activity and aldosterone in both nonpregnant and pregnant rats. Systolic blood pressure was not affected in nonpregnant rats. However, in pregnant rats, 0.9% sodium supplement prevented the decreased blood pressure. Moreover, an increase of systolic blood pressure was obtained in pregnant rats receiving 1.8% NaCl. The 0.9% sodium supplement did not affect plasma and fetal parameters. However, 1.8% NaCl supplement has larger effects during gestation as shown by increased plasma sodium concentration, hematocrit level, negative water balance, proteinuria, and intrauterine growth restriction. With both sodium supplements, decreased AT1 mRNA levels in the kidney and in the placenta were observed. Our results showed that a high-sodium intake prevents the pregnancy-induced decrease of blood pressure in rats. Nonpregnant rats were able to maintain homeostasis but not the pregnant ones in response to sodium load. Furthermore, pregnant rats on a high-sodium intake (1.8% NaCl) showed some physiological responses that resemble manifestations observed in preeclampsia.

Salt, Frusemide and Renin in Severe Experimental Renal Hypertension

1976 ◽  
Vol 51 (s3) ◽  
pp. 129s-132s
Author(s):  
M. Fernandes ◽  
G. Onesti ◽  
R. Dykyj ◽  
R. Fiorentini ◽  
Anne B. Gould ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Early Phase ◽  
Sodium Intake ◽  
Renal Hypertension ◽  
Deficient Diet ◽  
Blood Pressure Elevation ◽  
High Sodium ◽  
High Sodium Intake ◽  
Experimental Renal Hypertension ◽  
High Sodium Diet

1. Sodium-deficient diet failed to alter development and maintenance of severe renal hypertension produced in the rat by ligation of the aorta between the renal arteries. 2. High sodium diet did not alter the early phase of this hypertension, but significantly decreased blood pressure elevation in the late phases. 3. The decrease in blood pressure produced by high sodium intake does not appear to be mediated by renin suppression. 4. Frusemide effectively reduced blood pressure and renin at all phases.

Alterations in Cerebrospinal Fluid Angiotensin II by Sodium Intake in Patients with Essential Hypertension

1989 ◽  
Vol 77 (4) ◽  
pp. 389-394 ◽  
Author(s):  
Minoru Kawamura ◽  
Yuhei Kawano ◽  
Kaoru Yoshida ◽  
Masahito Imanishi ◽  
Satoshi Akabane ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Essential Hypertension ◽  
Sodium Intake ◽  
Ang Ii ◽  
Sodium Depletion ◽  
High Sodium ◽  
Sodium Diet ◽  
Low Sodium Diet ◽  
Low Sodium

1. Angiotensin (ANG) levels were measured in the cerebrospinal fluid of 15 patients with essential hypertension on a high sodium diet for 1 week and on a low sodium diet for a further week. ANGs were determined using a system of extraction by Sep-Pak cartridges followed by h.p.l.c. combined with radioimmunoassay. 2. Sodium depletion resulted in increases of ANG II in the cerebrospinal fluid from 1.16 ± 0.38 (sem) to 1.83 ± 0.43 fmol/ml (P < 0.01) and of ANG III from 0.65 ± 0.11 to 0.86 ± 0.15 fmol/ml (P < 0.01). 3. The ANG II level in the cerebrospinal fluid was found to be unchanged and recovery of added ANG II was approximately 90%, even after incubation for 3 h, on both diets. Thus, it is unlikely that ANG II is produced or degraded in the cerebrospinal fluid in vitro. 4. There was no significant correlation between the cerebrospinal fluid and the plasma ANG II concentration on the low sodium diet. 5. These results suggest that the cerebrospinal fluid ANG II level increases with sodium depletion, and that the effect of the level of ANG II on the activity of the angiotensin-forming system in the central nervous system may be assessed by determination of ANG II in the cerebrospinal fluid in patients with essential hypertension.

scholarly journals High Sodium Intake Strengthens the Association of ACE I/D Polymorphism with Blood Pressure in a Community

2007 ◽  
Vol 20 (7) ◽  
pp. 751-757 ◽  
Author(s):  
K YAMAGISHI ◽  
T TANIGAWA ◽  
R CUI ◽  
M TABATA ◽  
A IKEDA ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Sodium Intake ◽  
High Sodium ◽  
High Sodium Intake
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