scholarly journals Long-term exercise attenuates blood pressure responsiveness and modulates kidney angiotensin II signalling and urinary sodium excretion in SHR

2011 ◽  
Vol 12 (4) ◽  
pp. 394-403 ◽  
Author(s):  
Silmara Ciampone ◽  
Rafael Borges ◽  
Ize P de Lima ◽  
Flávia F Mesquita ◽  
Elizabeth C Cambiucci ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Exercise Training ◽  
Sodium Excretion ◽  
Urinary Sodium Excretion ◽  
Urinary Sodium ◽  
Receptor Expression ◽  
Spontaneously Hypertensive ◽  
Wistar Kyoto

Observations have been made regarding the effects of long-term exercise training on blood pressure, renal sodium handling and renal renin–angiotensin–aldosterone (RAS) intracellular pathways in conscious, trained Okamoto–Aoki spontaneously hypertensive rats (SHR) and Wistar Kyoto (WKy) normotensive rats, compared with appropriate age-matched sedentary SHR and WKy. To evaluate the influence of exercise training on renal function and RAS, receptors and intracellular angiotensin II (AngII) pathway compounds were used respectively, and lithium clearance and western blot methods were utilised. The current study demonstrated that increased blood pressure in SHR was blunted and significantly reduced by long-term swim training between the ages of 6 and 16 weeks. Additionally, the investigators observed an increased fractional urinary sodium excretion in trained SHR (SHRT) rats, compared with sedentary SHR (SHRS), despite a significantly decreased creatinine clearance (CCr). Furthermore, immunoblotting analysis demonstrated a decreased expression of AT1R in the entire kidney of TSHR rats, compared with SSHR. Conversely, the expression of the AT2R, in both sedentary and trained SHR, was unchanged. The present study may indicate that, in the kidney, long-term exercise exerts a modulating effect on AngII receptor expression. In fact, the present study indicates an association of increasing natriuresis, reciprocal changes in renal AngII receptors and intracellular pathway proteins with the fall in blood pressure levels observed in TSHR rats compared with age-matched SSHR rats.

scholarly journals Effects of Prehypertensive Losartan Treatment on Resistance Vessel Remodeling and Angiotensin II Type 1 Receptor Expression in Spontaneously Hypertensive Rats

2020 ◽  
Vol 33 (5) ◽  
pp. 471-471
Author(s):  
Ting-jun Wang ◽  
Wan-ru Chen ◽  
Xu Lin ◽  
Gui-li Lian ◽  
Chang-sheng Xu ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Receptor Expression ◽  
Mesenteric Arteries ◽  
Resistance Vessel ◽  
Spontaneously Hypertensive ◽  
Vessel Remodeling ◽  
Wistar Kyoto ◽  
Losartan Treatment

Abstract Background To study the effects of prehypertensive losartan treatment on blood pressure, resistance vessel remodeling, and angiotensin II type 1 receptor (AT1R) expression in adult spontaneously hypertensive rats (SHRs). Methods Four-week-old SHR and Wistar-Kyoto rats were randomly divided into losartan-treated and untreated groups. Losartan was administrated by gavage from 4 to 10 weeks old. Blood pressure was monitored by the tail-cuff method till 26 weeks old. The third grade mesenteric arteries were then isolated. Vessel structure, relaxation reactivity, angiotensin II type 1 receptor expression, and angiotensin II levels were analyzed. Results Losartan treatment from 4 to 10 weeks of age significantly lowered systolic blood pressure from 10 to 26 weeks in SHR. At 26 weeks old, wall thickness to lumen radius and wall area to lumen area of mesenteric arteries were significantly lower in losartan-treated than untreated SHR (P < 0.01). Maximum relaxation to acetylcholine and its pD2 were increased in losartan-treated compared to untreated SHR (P < 0.01). Angiotensin II type 1 receptor mRNA and protein levels were significantly reduced in losartan-treated SHR (P < 0.01). However, angiotensin II levels in plasma and mesenteric arteries of losartan-treated SHR were higher than those of untreated SHR (P < 0.05). Losartan treatment lowered systolic blood pressure in Wistar-Kyoto at the age of 10 weeks (P < 0.05), but had no significant effect on blood pressure after 14 weeks or mesenteric arteries at 26 weeks. Conclusions Blood pressure reduction induced by prehypertensive losartan treatment ameliorates resistance vessel remodeling and downregulates angiotensin II type 1 receptor expression in adult SHR.

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.

scholarly journals Urinary sodium excretion and the risk of cardiovascular disease: A community-based cohort study in Taiwan

2021 ◽  
pp. 1-42
Author(s):  
Yi-Jie Wang ◽  
Kuo-Lioug Chien ◽  
Hsiu-Ching Hsu ◽  
Hung-Ju Lin ◽  
Ta-Chen Su ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Metabolic Syndrome ◽  
Systolic Blood Pressure ◽  
Sodium Excretion ◽  
Urinary Sodium Excretion ◽  
Salt Sensitivity ◽  
Urinary Sodium ◽  
Mediating Effect ◽  
Cvd Risk ◽  
Media Thickness

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.

Hypoxic pressor response, cardiac size, and natriuretic peptides are modified by long-term intermittent hypoxia

1999 ◽  
Vol 87 (6) ◽  
pp. 2025-2031 ◽  
Author(s):  
Holger Kraiczi ◽  
Jarkko Magga ◽  
Xiang Ying Sun ◽  
Heikki Ruskoaho ◽  
Xiaohe Zhao ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Body Weight ◽  
Atrial Natriuretic Peptide ◽  
Right Ventricular ◽  
Natriuretic Peptide ◽  
Intermittent Hypoxia ◽  
Spontaneously Hypertensive ◽  
Wistar Kyoto

We investigated whether the effect of long-term intermittent hypoxia (LTIH) on cardiovascular function may be modified by preexisting genetic traits. To induce LTIH experimentally, cycles of 90-s hypoxia (nadir 6%) followed by 90-s normoxia were applied to six Wistar-Kyoto and six spontaneously hypertensive rats during 8 h daily. Comparison with the same number of control animals after 70 days revealed no alteration of intra-arterial blood pressure or heart rate. Blood pressure responsiveness to a brief hypoxic stimulus was enhanced in the LTIH animals, regardless of strain, whereas the hypoxia-induced increase in heart rate was abolished. In the spontaneously hypertensive but not the Wistar-Kyoto rats, LTIH increased left ventricular weight-to-body weight ratio and content of atrial natriuretic peptide mRNA. Expression of B-type natriuretic peptide was unchanged (Northern blot). Slightly increased right ventricular weight-to-body weight ratios in the LTIH animals were associated with higher right ventricular atrial natriuretic peptide and B-type natriuretic peptide mRNA amounts. Consequently, the effects of LTIH on different components of cardiovascular function appear incompletely related to each other and differentially influenced by constitutional traits.

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

scholarly journals Genetic deletion of AT1a receptors attenuates intracellular accumulation of ANG II in the kidney of AT1a receptor-deficient mice

2007 ◽  
Vol 293 (2) ◽  
pp. F586-F593 ◽  
Author(s):  
Xiao C. Li ◽  
L. Gabriel Navar ◽  
Yuan Shao ◽  
Jia L. Zhuo
Keyword(s):  
Blood Pressure ◽  
Sodium Excretion ◽  
Rat Kidney ◽  
Systolic Pressure ◽  
Weight Ratio ◽  
Urinary Sodium Excretion ◽  
Urinary Sodium ◽  
Ang Ii ◽  
Wild Type ◽  
Deficient Mice

We and others have previously shown that high levels of ANG II are accumulated in the rat kidney via a type 1 (AT1) receptor-mediated mechanism, but it is not known which AT1 receptor is involved in this process in rodents. We tested the hypothesis that AT1a receptor-deficient mice (Agtr1a−/−) are unable to accumulate ANG II intracellularly in the kidney because of the absence of AT1a receptor-mediated endocytosis. Adult male wild-type (Agtr1a+/+), heterozygous (Agtr1a+/−), and Agtr1a−/− were treated with vehicle, ANG II (40 ng/min ip via osmotic minipump), or ANG II plus the AT1 antagonist losartan (10 mg·kg−1·day−1 po) for 2 wk. In wild-type mice, ANG II induced hypertension (168 ± 4 vs. 113 ± 3 mmHg, P < 0.001), increased kidney-to-body weight ratio ( P < 0.01), caused pressure natriuresis ( P < 0.05), and elevated plasma and whole kidney ANG II levels ( P < 0.001). Concurrent administration of ANG II with losartan attenuated these responses to ANG II. In contrast, Agtr1a−/− mice had lower basal systolic pressures ( P < 0.001), smaller kidneys with much fewer AT1b receptors ( P < 0.001), higher basal 24-h urinary sodium excretion ( P < 0.01), as well as basal plasma and whole kidney ANG II levels ( P < 0.01). However, intracellular ANG II levels in the kidney were lower in Agtr1a−/− mice. In Agtr1a−/− mice, ANG II slightly increased systolic pressure ( P < 0.05) but had no effect on the kidney weight, urinary sodium excretion, and whole kidney ANG II levels. Losartan restored systolic pressure to basal levels and decreased whole kidney ANG II levels by ∼20% ( P < 0.05). These results demonstrate a predominant role of AT1a receptors in blood pressure regulation and in the renal responses to long-term ANG II administration, that AT1b receptors may play a limited role in blood pressure control and mediating intrarenal ANG II accumulation in the absence of AT1a receptors.

Sign in / Sign up

Export Citation Format

Share Document