High salt intake and blood pressure in lower primates (Papio hamadryas)

1976 ◽  
Vol 40 (4) ◽  
pp. 601-604 ◽  
Author(s):  
G. M. Cherchovich ◽  
K. Capek ◽  
Z. Jefremova ◽  
I. Pohlova ◽  
J. Jelinek

One year of increased salt intake in monkeys elevates mean blood pressure significantly. This effect is more marked in animals exposed just after birth. In animals exposed as adults, the response in males is more pronounced than in females, mainly due to a marked increase of pulse pressure. Th hypertensive response was potentiated by reduction of renal mass, which caused GFR values (in terms of body weight) to decrease compared with intact salt-fed animals, in which GFR values were elevated above the control level. It is concluded that the mechanisms involved in the hypertensive response are similar to those in the rat and dog.

1968 ◽  
Vol 46 (2) ◽  
pp. 179-188 ◽  
Author(s):  
D. Ostrovsky ◽  
F. R. Papsin ◽  
A. G. Gornall

For several weeks after partial constriction of one renal artery, the fate of this "clipped" kidney seems to exert a determining influence on blood pressure. Rats that remained hypertensive throughout the experiment almost invariably had clipped kidneys averaging 0.16 to 0.22% of body weight. Below 0.1%, this kidney was usually quite atrophic, and its presence was consistent with falling or normal blood pressure. The untouched kidney in such rats was, on the average, heavier in the hypertensive than in the normotensive animals. Since the latter also had less renal tissue on the clipped side, it appears that factors leading to high blood pressure stimulated hypertrophy beyond the level provoked by renoprival factors. In rats on a high salt intake, 5 μg/day of D-aldosterone for 3 months stimulated significant true renal hypertrophy in the absence of a rise in blood pressure. Such hypertrophy was more pronounced in similar rats that had been getting 250 μg DOCA/day for 3 months but were also normotensive. Rats that developed hypertension on this latter regimen had still heavier kidneys. Renal hypertrophy appears to be a prehypertensive phenomenon which persists and can become even more pronounced in hypertension. The highest levels of renal hypertrophy were usually associated with significant adrenal hypertrophy. Endocrine functions may be involved in renal hypertrophy. This concept is discussed in relation to a phospholipid "renin inhibitor" recently isolated from dog and hog kidneys.


2011 ◽  
Vol 110 (2) ◽  
pp. 468-471 ◽  
Author(s):  
Mirian J. Starmans-Kool ◽  
Alice V. Stanton ◽  
Yun Y. Xu ◽  
Simon A. McG Thom ◽  
Kim H. Parker ◽  
...  

Dietary salt intake is associated with high brachial blood pressure (BP) and increased risk of cardiovascular disease. We investigated whether changes in dietary salt intake are associated with changes in central BP and wave reflection in healthy volunteers. Ten healthy normotensive male volunteers (22–40 yr) participated in a 6-wk double-blind randomized crossover study to compare a low-dietary salt intake (60–80 mmol sodium/day) with a high-salt intake (low salt intake supplemented with 128 mmol sodium/day) on central BP and wave reflection. Brachial and carotid BP, carotid blood flow velocity, forward (Pf) and backward (Pb) pressure, wave intensity, body weight, and urinary electrolyte excretion were measured at the end of each crossover period. High salt intake significantly increased carotid systolic BP [98 (SD 11) vs. 91 mmHg (SD 13), P < 0.01] and increased wave reflection [ratio of backward to forward pressure (Pb/Pf) 0.13 (SD 0.02) vs. 0.11 (SD 0.03), P = 0.04] despite only small effects on brachial BP [114 (SD 9) vs. 112 mmHg (SD 6), P = 0.1]. Urinary sodium excretion and body weight were also increased following high salt intake. High salt intake disproportionately increases central BP compared with brachial BP as a result of enhanced wave reflection. These effects may contribute to the adverse effect of high dietary salt intake on the risk of cardiovascular disease.


2011 ◽  
Vol 301 (2) ◽  
pp. F263-F270 ◽  
Author(s):  
M. C. Fiore ◽  
P. M. Jimenez ◽  
D. Cremonezzi ◽  
L. I. Juncos ◽  
N. H. García

High salt intake (HS) is a risk factor for cardiovascular and kidney disease. Indeed, HS may promote blood-pressure-independent tissue injury via inflammatory factors. The lipid-lowering 3-hydroxy 3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors exert beneficial lipid-independent effects, reducing the expression and synthesis of inflammatory factors. We hypothesized that HS impairs kidney structure and function in the absence of hypertension, and these changes are reversed by atorvastatin. Four groups of rats were treated for 6 wk in metabolic cages with their diets: normal salt (NS); HS, NS plus atorvastatin and HS plus atorvastatin. We measured basal and final body weight, urinary sodium and protein excretion (UProtV), and systolic blood pressure (SBP). At the end of the experimental period, cholesterolemia, creatinine clearance, renal vascular reactivity, glomerular volume, cortical and glomerular endothelial nitric oxide synthase (eNOS), and transforming growth factor (TGF)-β1 expression were measured. We found no differences in SBP, body weight, and cholesterolemia. HS rats had increased creatinine clearence, UProtV, and glomerular volume at the end of the study. Acetylcholine-induced vasodilatation decreased by 40.4% in HS rats ( P < 0.05). HS decreased cortical and glomerular eNOS and caused mild glomerular sclerosis, interstitial mononuclear cell infiltration, and increased cortical expression of TGF-β1. All of these salt-induced changes were reversed by atorvastatin. We conclude that long-term HS induces inflammatory and hemodynamic changes in the kidney that are independent of SBP. Atorvastatin corrected all, suggesting that the nitric oxide-oxidative stress balance plays a significant role in the earlier stages of salt induced kidney damage.


1994 ◽  
Vol 267 (5) ◽  
pp. H1707-H1712 ◽  
Author(s):  
A. W. Cowley ◽  
M. M. Skelton ◽  
P. E. Papanek ◽  
A. S. Greene

Reduction of renal mass (RRM) combined with a high-salt diet results in volume retention, a rise of cardiac output, and hypertension. The present studies were designed to determine whether prevention of volume retention would alter the rise of mean arterial pressure (MAP) in RRM rats given high salt. Rats were studied in a modified metabolic cage to permit continuous determination of total body weight (TBW). In group 1, NaCl was increased from 1 to 14.5 meq/day and delivered isotonically. In group 2, NaCl was increased while TBW was servo-controlled to a constant level. Group 3 was also servo-controlled, but rats received an intravenous infusion of an arginine vasopressin V1 antagonist throughout the study. MAP in group 1 rose 24 mmHg by day 4 of high salt with a parallel increase of TBW of 26 g. In group 2, MAP rose 48 mmHg by day 4 of high salt, while TBW was controlled to within 0.6% of control body weight. With inhibition of vasopressin V1 receptors (group 3), MAP rose 39 mmHg. Nearly equivalent amounts of NaCl were retained in all groups, which was associated with no change of plasma Na in group 1 but an increase of nearly 7 meq/ml in groups 2 and 3. Hematocrit fell nearly 9% in groups 2 and 3 compared with a 4% reduction in group 1. The results suggest that under conditions where net retention cannot occur, high salt intake increases MAP by an osmotically driven fluid transfer from cells, which results in an even greater expansion of blood volume.(ABSTRACT TRUNCATED AT 250 WORDS)


2018 ◽  
Vol 69 (10) ◽  
pp. 2845-2849
Author(s):  
Daniela Gurgus ◽  
Elena Ardeleanu ◽  
Carmen Gadau ◽  
Roxana Folescu ◽  
Ioan Tilea ◽  
...  

The objectives of the present study were to evaluate the prevalence of resistant hypertension (RH) in primary care setting and to analyse its biochemical and clinical characteristics. After 3 months of treatment and evaluation, 721 (14.01%) of 5,146 patients with hypertension did not reach target office blood pressure of [ 140/90 mmHg. After exclusion of �white-coat effect� with ambulatory blood pressure, of secondary and pseudo- resistant hypertension, prevalence of RH was 6.74%. Lifestyle factors associated with RH were physical inactivity, obesity, high salt intake, smoking and excessive alcohol ingestion. Compared to controlled hypertension, RH patients presented higher incidence of family history of cardiovascular disease (38.90% vs 25.94%), diabetes mellitus (34.87% vs 19.01%), impaired fasting glucose (21.91% vs 19.07%), target organ damage (29.1% vs 15.95%), and cardiovascular disease (27.09% vs 17.06%). Dyslipidaemia (52.90% vs 42.03%), fasting plasma glucose (116.10�38.9 vs 107.80�37.2), HbA1c (6.41�1.42 vs 5.96�0.94), serum creatinine (1.09�0.27 vs 1.03�0.24) and microalbuminuria (21.90% vs 10.95%) were significantly higher in RH. Predictors of RH, determined by a multivariate logistic regression analysis were left ventricular hypertrophy (OD 2.14, 95% CI 1.32-3.69), renal impairment expressed as eGFR [ 60 ml/min/1.73m2 (OD 1.62, 95% CI 1.21-2.21) and the presence of cardiovascular disease (OD 1.48, 95% CI 1.02-2.16).


1984 ◽  
Vol 66 (4) ◽  
pp. 427-433 ◽  
Author(s):  
Ottar Gudmundsson ◽  
Hans Herlitz ◽  
Olof Jonsson ◽  
Thomas Hedner ◽  
Ove Andersson ◽  
...  

1. During 4 weeks 37 normotensive 50-year-old men identified by screening in a random population sample were given 12 g of NaCl daily, in addition to their usual dietary sodium intake. Blood pressure, heart rate, weight, urinary excretion of sodium, potassium and catecholamines, plasma aldosterone and noradrenaline and intra-erythrocyte sodium content were determined on normal and increased salt intake. The subjects were divided into those with a positive family history of hypertension (n = 11) and those without such a history (n = 26). 2. Systolic blood pressure and weight increased significantly irrespective of a positive family history of hypertension. 3. On normal salt intake intra-erythrocyte sodium content was significantly higher in those with a positive family history of hypertension. During high salt intake intra-erythrocyte sodium content decreased significantly in that group and the difference between the hereditary subgroups was no longer significant. 4. In the whole group urinary excretion of noradrenaline, adrenaline and dopamine increased whereas plasma aldosterone decreased during the increased salt intake. 5. Thus, in contrast to some earlier studies performed in young subjects, our results indicate that moderately increased sodium intake acts as a pressor agent in normotensive middle-aged men whether there was a positive family history of hypertension or not. We confirm that men with positive family history of hypertension have an increased intra-erythrocyte sodium content, and that an increase in salt intake seems to increase overall sympathetic activity.


2018 ◽  
Vol 41 (7) ◽  
pp. 378-384 ◽  
Author(s):  
Alper Erdan ◽  
Abdullah Ozkok ◽  
Nadir Alpay ◽  
Vakur Akkaya ◽  
Alaattin Yildiz

Background: Arterial stiffness is a strong predictor of mortality in hemodialysis patients. In this study, we aimed to investigate possible relations of arterial stiffness with volume status determined by bioimpedance analysis and aortic blood pressure parameters. Also, effects of a single hemodialysis session on these parameters were studied. Methods: A total of 75 hemodialysis patients (M/F: 43/32; mean age: 53 ± 17) were enrolled. Carotid-femoral pulse wave velocity, augmentation index, and aortic pulse pressure were measured by applanation tonometry before and after hemodialysis. Extracellular fluid and total body fluid volumes were determined by bioimpedance analysis. Results: Carotid-femoral pulse wave velocity (9.30 ± 3.30 vs 7.59 ± 2.66 m/s, p < 0.001), augmentation index (24.52 ± 9.42 vs 20.28 ± 10.19, p < 0.001), and aortic pulse pressure (38 ± 14 vs 29 ± 8 mmHg, p < 0.001) significantly decreased after hemodialysis. Pre-dialysis carotid-femoral pulse wave velocity was associated with age (r2 = 0.15, p = 0.01), total cholesterol (r2 = 0.06, p = 0.02), peripheral mean blood pressure (r2 = 0.10, p = 0.005), aortic-mean blood pressure (r2 = 0.06, p = 0.02), aortic pulse pressure (r2 = 0.14, p = 0.001), and extracellular fluid/total body fluid (r2 = 0.30, p < 0.0001). Pre-dialysis augmentation index was associated with total cholesterol (r2 = 0.06, p = 0,02), aortic-mean blood pressure (r2 = 0.16, p < 0.001), and aortic pulse pressure (r2 = 0.22, p < 0.001). Δcarotid-femoral pulse wave velocity was associated with Δaortic-mean blood pressure (r2 = 0.06, p = 0.02) and inversely correlated with baseline carotid-femoral pulse wave velocity (r2 = 0.29, p < 0.001). Pre-dialysis Δaugmentation index was significantly associated with Δaortic-mean blood pressure (r2 = 0.09, p = 0.009) and Δaortic pulse pressure (r2 = 0.06, p = 0.03) and inversely associated with baseline augmentation index (r2 = 0.14, p = 0.001). In multiple linear regression analysis (adjusted R2 = 0.46, p < 0.001) to determine the factors predicting Log carotid-femoral pulse wave velocity, extracellular fluid/total body fluid and peripheral mean blood pressure significantly predicted Log carotid-femoral pulse wave velocity (p = 0.001 and p = 0.006, respectively). Conclusion: Carotid-femoral pulse wave velocity, augmentation index, and aortic pulse pressure significantly decreased after hemodialysis. Arterial stiffness was associated with both peripheral and aortic blood pressure. Furthermore, reduction in arterial stiffness parameters was related to reduction in aortic blood pressure. Pre-dialysis carotid-femoral pulse wave velocity was associated with volume status determined by bioimpedance analysis. Volume control may improve not only the aortic blood pressure measurements but also arterial stiffness in hemodialysis patients.


Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Keyona N King-Medina ◽  
Emily Henson ◽  
Pablo Ortiz

Human consumption of fructose as a sweetener has increased in the past 30 years. High fructose intake has been implicated in the development of hypertension, diabetes, and obesity. In the US, the upper 10th percentile of the population consumes up to 40% of their caloric intake from added sugars, in which fructose represents half of these. Fructose metabolism is strikingly different from that of glucose. Yet, the effect of a fructose or glucose-enriched diet in salt handling by the kidney, affecting blood pressure, and its interaction with high salt intake has been poorly studied. In genetic models of salt-sensitive hypertension, the activity of the Na + /K + /2Cl - cotransporter (NKCC2) in the thick ascending limb (TAL) is abnormally enhanced. We hypothesized that chronic fructose in drinking water induces a salt-dependent increase in blood pressure and stimulates NKCC2 during high salt intake in normal rats. Sprague-Dawley rats were given 20% fructose or 20% glucose in drinking water for 1 week after which a high salt (HS) diet (4% Na + in chow) was started for 3 weeks. When we measured systolic blood pressure (SBP) by tail cuff plethysmography in fructose-fed and glucose-fed rats on a HS diet, only the fructose-fed rats had an increased SBP from 120±10 to 132±6 mmHg on day 7 of HS (p<0.01). SBP continued to increase up to 144±18 mmHg after 3 weeks (p<0.01 vs glucose). Fructose or glucose alone did not increase SBP after 4 weeks. We then repeated the protocol using radiotelemetry to monitor the blood pressure (BP). In rats fed fructose, by day 5 of HS the SBP increased by 12±3 mmHg (p<0.02) and SBP remained elevated for 3 weeks (delta: 10±2.5 mmHg, n=3). In rats fed glucose, a HS diet did not significantly change SBP for 3 weeks (n=5). Moreover, NKCC2 activity in the TAL is enhanced by phosphorylation at Thr96, 101. We found that NKCC2 phosphorylation was higher in rats fed fructose plus HS (p<0.02) but not in rats fed glucose plus HS for 3 weeks (HS: 100, fructose+HS: 250±40%, glucose+HS: 95±10%). Therefore, we conclude that a high fructose (but not a glucose) diet in normal rats induces a salt-dependent increase in BP independently from caloric intake. Thus, the increase in BP may in part be due to the stimulation of NKCC2 phosphorylation in the TAL by fructose.


Author(s):  
Christine Y Bakhoum ◽  
Cheryl A M Anderson ◽  
Stephen P Juraschek ◽  
Casey M Rebholz ◽  
Lawrence J Appel ◽  
...  

Abstract BACKGROUND Uromodulin modulates the sodium-potassium-two-chloride transporter in the thick ascending limb of the loop of Henle, and its overexpression in murine models leads to salt-induced hypertension. We hypothesized that individuals with higher baseline levels of urine uromodulin would have a greater increase in systolic blood pressure (SBP) for the same increase in sodium compared with those with lower uromodulin levels. METHODS We used data from 157 subjects randomized to the control diet of the Dietary Approaches to Stop Hypertension (DASH)-Sodium trial who were assigned to 30 days of low (1,500 mg/d), medium (2,400 mg/d), and high salt (3,300 mg/d) diets in random order. Blood pressure was measured prerandomization and then weekly during each feeding period. We evaluated the association of prerandomization urine uromodulin with change in SBP between diets, as measured at the end of each feeding period, using multivariable linear regression. RESULTS Baseline urine uromodulin stratified by tertiles was ≤17.64, 17.65–31.97, and ≥31.98 µg/ml. Across the tertiles, there were no significant differences in SBP at baseline, nor was there a differential effect of sodium diet on SBP across tertiles (low to high, P = 0.81). After adjusting for age, sex, body mass index, and race, uromodulin levels were not significantly associated with SBP change from low to high sodium diet (P = 0.42). CONCLUSIONS In a randomized trial of different levels of salt intake, higher urine uromodulin levels were not associated with a greater increase in blood pressure in response to high salt intake.


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