Prevention of fatal hemorrhagic shock in dog by pretreatment with chronic high-salt diet

1985 ◽  
Vol 249 (3) ◽  
pp. H577-H584
Author(s):  
A. P. Rocchini ◽  
K. P. Gallagher ◽  
M. J. Botham ◽  
J. H. Lemmer ◽  
C. A. Szpunar ◽  
...  

The ability of a chronic high-salt diet to prevent fatal hemorrhagic shock was examined in 36 mongrel dogs. Twenty-one dogs received a dietary supplement of 9 g sodium chloride/day for 6 wk, and 15 dogs received the same basic diet for 6 wk but without the sodium chloride supplement. Hemorrhagic shock was induced in all dogs by bleeding into an overhanging sealed reservoir. After 3 h of shock, salt-pretreated dogs had a lower systemic vascular resistance of 0.70 +/- 0.02 versus 1.44 +/- 0.04 mmHg X ml-1 X min X kg (P less than 0.01) and a higher cardiac output of 53 +/- 3 versus 26 +/- 3 ml X min-1 X kg-1 (P less than 0.01) than was observed in controls. At 2.5 h of shock, the salt-pretreated dogs also experienced an increase in gastrointestinal (P less than 0.01), hepatic arterial, (P less than 0.05), kidney (P less than 0.05), brain (P less than 0.01), and heart blood flows (P less than 0.001) compared with 0.5 h of shock, whereas the control dogs experienced no increased flow during this same period. We also observed that after 3 h of hypotension there was a significantly smaller increase in plasma renin activity in the salt-pretreated dogs. Administration of 0.1 U X kg-1 X min-1 of hog renin eliminated the differences in systemic vascular resistance, cardiac output, and survival in five salt-pretreated dogs.

1992 ◽  
Vol 83 (1) ◽  
pp. 13-22 ◽  
Author(s):  
J. Bouhnik ◽  
J. P. Richoux ◽  
H. Huang ◽  
F. Savoie ◽  
T. Baussant ◽  
...  

1. The renin-angiotensin and kinin-kallikrein systems of Dahl salt-sensitive and salt-resistant rats fed diets with different salt contents were analysed using biochemical and immunocytochemical techniques. 2. Blood pressure increased by 45% in salt-sensitive rats only, after 4 weeks on a high-salt diet. The plasma renin activity and plasma angiotensin II concentration remained at the same levels in salt-sensitive rats on the high-salt diet as on the normal salt diet, whereas the plasma renin activity and plasma angiotensin II concentration of salt-resistant rats fed the high-salt diet were lower. The plasma renin activity and the plasma angiotensin II concentration were elevated in both salt-resistant and salt-sensitive rats fed the salt-deficient diet but were much more elevated in salt-resistant than in salt-sensitive rats. 3. The kidney immunocytochemical data paralleled the data on plasma parameters. Salt-sensitive rats had fewer renin positive juxtaglomerular apparatuses than salt-resistant rats on the normal diet, and the increase on the sodium-deficient diet was also smaller in salt-sensitive rats. Salt-sensitive rats fed the high-salt diet and the standard diet had almost no angiotensin II immunoreactivity compared with the salt-resistant rats on the same diets. 4. The total renal kallikrein content of salt-sensitive rats was lower than that of salt-resistant rats on all three diets, as was the amount of kallikrein excreted in the urine on the standard and the high-salt diets. The differences resulted from a reduction in active kallikrein. The increase in kallikrein in salt-sensitive and salt-resistant rats on the salt-deficient diet was not significantly different. 5. There were similar changes in immunopositive kallikrein in the kidneys of salt-sensitive and salt-resistant rats with diet, with a large increase in kallikrein biosynthesis on the low-salt diet. The plasma concentration of high-molecular-mass kininogen was not significantly different in salt-sensitive and salt-resistant rats, but there was a significant increase in T-kininogen in salt-sensitive rats fed the high-salt diet. 6. In conclusion, the absence of decreases in the plasma renin activity and the plasma angiotensin II concentration in salt-sensitive rats fed the high-salt diet might partially explain the increase in blood pressure.


2020 ◽  
Vol 8 (1) ◽  
pp. e001039
Author(s):  
Eliane F E Wenstedt ◽  
Nienke M G Rorije ◽  
Rik H G Olde Engberink ◽  
Kim M van der Molen ◽  
Youssef Chahid ◽  
...  

IntroductionPatients with type 1 diabetes are susceptible to hypertension, possibly resulting from increased salt sensitivity and accompanied changes in body fluid composition. We examined the effect of a high-salt diet (HSD) in type 1 diabetes on hemodynamics, including blood pressure (BP) and body fluid composition.Research design and methodsWe studied eight male patients with type 1 diabetes and 12 matched healthy controls with normal BP, body mass index, and renal function. All subjects adhered to a low-salt diet and HSD for eight days in randomized order. On day 8 of each diet, extracellular fluid volume (ECFV) and plasma volume were calculated with the use of iohexol and 125I-albumin distribution. Hemodynamic measurements included BP, cardiac output (CO), and systemic vascular resistance.ResultsAfter HSD, patients with type 1 diabetes showed a BP increase (mean arterial pressure: 85 (5) mm Hg vs 80 (3) mm Hg; p<0.05), while BP in controls did not rise (78 (5) mm Hg vs 78 (5) mm Hg). Plasma volume increased after HSD in patients with type 1 diabetes (p<0.05) and not in controls (p=0.23). There was no significant difference in ECFV between diets, while HSD significantly increased CO, heart rate (HR) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in type 1 diabetes but not in controls. There were no significant differences in systemic vascular resistance, although there was a trend towards an HSD-induced decrease in controls (p=0.09).ConclusionsIn the present study, patients with type 1 diabetes show a salt-sensitive BP rise to HSD, which is accompanied by significant increases in plasma volume, CO, HR, and NT-proBNP. Underlying mechanisms for these responses need further research in order to unravel the increased susceptibility to hypertension and cardiovascular disease in diabetes.Trial registration numbersNTR4095 and NTR4788.


2019 ◽  
Vol 316 (5) ◽  
pp. R563-R570 ◽  
Author(s):  
Mediha Becirovic-Agic ◽  
Sofia Jönsson ◽  
Maria K. Tveitarås ◽  
Trude Skogstrand ◽  
Tine V. Karlsen ◽  
...  

The genetic background of a mouse strain determines its susceptibility to disease. C57BL/6J and Balb/CJ are two widely used inbred mouse strains that we found react dramatically differently to angiotensin II and high-salt diet (ANG II + Salt). Balb/CJ show increased mortality associated with anuria and edema formation while C57BL/6J develop arterial hypertension but do not decompensate and die. Clinical symptoms of heart failure in Balb/CJ mice gave the hypothesis that ANG II + Salt impairs cardiac function and induces cardiac remodeling in male Balb/CJ but not in male C57BL/6J mice. To test this hypothesis, we measured cardiac function using echocardiography before treatment and every day for 7 days during treatment with ANG II + Salt. Interestingly, pulsed wave Doppler of pulmonary artery flow indicated increased pulmonary vascular resistance and right ventricle systolic pressure in Balb/CJ mice, already 24 h after ANG II + Salt treatment was started. In addition, Balb/CJ mice showed abnormal diastolic filling indicated by reduced early and late filling and increased isovolumic relaxation time. Furthermore, Balb/CJ exhibited lower cardiac output compared with C57BL/6J even though they retained more sodium and water, as assessed using metabolic cages. Left posterior wall thickness increased during ANG II + Salt treatment but did not differ between the strains. In conclusion, ANG II + Salt treatment causes early restriction of pulmonary flow and reduced left ventricular filling and cardiac output in Balb/CJ, which results in fluid retention and peripheral edema. This makes Balb/CJ a potential model to study the adaptive capacity of the heart for identifying new disease mechanisms and drug targets.


2003 ◽  
Vol 88 (9) ◽  
pp. 4180-4185 ◽  
Author(s):  
Michiel N. Kerstens ◽  
Frank G. H. van der Kleij ◽  
Arnold H. Boonstra ◽  
Wim J. Sluiter ◽  
Jan Koerts ◽  
...  

We studied cortisol metabolism together with insulin sensitivity [homeostatic model assessment (HOMA)] and renal hemodynamics in 19 salt-resistant (sr) and nine salt-sensitive (ss) normotensive subjects after a low- and high-salt diet. Results are described as high- vs. low-salt diet. Sum of urinary cortisol metabolite excretion (∑metabolites) increased in sr subjects (3.8 ± 1.6 vs. 3.1 ± 1.1 μg/min per square meter, P &lt; 0.05) and decreased in ss subjects (2.3 ± 1.0 vs. 2.9 ± 1.1 μg/min per square meter, P &lt; 0.05). Plasma 0830 h cortisol decreased in sr subjects but did not change significantly in ss subjects. In all subjects, the absolute blood pressure change correlated negatively with the percentage change in ∑metabolites (P &lt; 0.05) and positively with the percentage change in renal vascular resistance (P &lt; 0.05). ∑metabolites during high-salt diet correlated negatively with the percentage changes in plasma 0830 h cortisol (P &lt; 0.05) and renal vascular resistance (P = 0.05). HOMA did not change in either group, but the percentage change in HOMA correlated positively with the percentage change in plasma cortisol (P = 0.001) and negatively with the percentage change in ∑metabolites (P &lt; 0.01). Parameters of 11β-hydroxysteroid dehydrogenase activity were not different between groups and did not change. In conclusion, these data suggest that cortisol elimination is affected differently after salt loading in sr and ss subjects. Changes in circulating cortisol might contribute to individual sodium-induced alterations in insulin sensitivity.


1987 ◽  
Vol 252 (5) ◽  
pp. R833-R841 ◽  
Author(s):  
R. J. Roman ◽  
J. L. Osborn

Renal transplantation studies have indicated that some form of renal dysfunction underlies the development of hypertension in Dahl salt-sensitive (S) rats. In the present study, we compared renal hemodynamic and tubular function of conscious Dahl S and salt-resistant (R) rats. Prehypertensive Dahl S rats had a blunted natriuretic response to an intravenous isotonic sodium chloride load compared with the responses of normotensive Dahl R or hypertensive Dahl S rats. This difference was probably not related to a generalized defect in renal tubular handling of sodium and water, since prehypertensive Dahl S rats excreted quantities of sodium comparable to those of R or hypertensive S rats when infused with hypertonic sodium chloride solutions. Dahl S rats also elevated free water clearance and lowered urine osmolality similar to R rats when challenged with a hypotonic saline load. Renal blood flows and glomerular filtration rates were similar in prehypertensive Dahl S, hypertensive Dahl S, and Dahl R rats. The possible link between sodium retention and the development of hypertension in Dahl S rats was examined further by measuring the changes in sodium and water balance, extracellular fluid volume (ECV), and blood pressure after exposure to an 8% sodium chloride diet. No differences could be detected in the salt and water balances of Dahl S and R rats exposed to a high-salt diet for 14 days. ECV increased significantly by 10% in Dahl S rats on the 1st day of a high-salt diet, whereas no change was observed in Dahl R animals.(ABSTRACT TRUNCATED AT 250 WORDS)


2006 ◽  
Vol 290 (3) ◽  
pp. R553-R559 ◽  
Author(s):  
Paolo Manunta ◽  
Bruce P. Hamilton ◽  
John M. Hamlyn

High-salt diets elevate circulating Na+ pump inhibitors, vascular resistance, and blood pressure. Ouabain induces a form of hypertension mediated via the α2-Na+ pump isoform and the calcium influx mode of the vascular sodium calcium exchanger (NCX). Whereas elevated levels of an endogenous ouabain (EO) and NCX have been implicated in salt-sensitive hypertension, acute changes in sodium balance do not affect plasma EO. This study investigated the impact of longer-term alterations in sodium balance on the circulating levels and renal clearance of EO in normal humans. Thirteen normal men consumed a normal diet, high-salt diet, and hydrochlorothiazide (HCTZ), each for 5-day periods to alter sodium balance. EO and other humoral and urinary variables were determined daily. On a normal diet, urinary sodium excretion (140 ± 16 meq/day), plasma EO (0.43 ± 0.08 nmol/l) and urinary EO excretion (1.04 ± 0.13 nmol/day) were at steady state. On the 3rd day of a high-salt diet, urine sodium excretion (315 ± 28 meq/day), plasma EO (5.8 ± 2.2 nmol/l), and the urinary EO excretion (1.69 ± 0.27 nmol/day) were significantly increased, while plasma renin activity and aldosterone levels were suppressed. The salt-evoked increase in plasma EO was greater in older individuals, in subjects whose baseline circulating EO was higher, and in those with low renal clearance. During HCTZ, body weight decreased and plasma renin activity, aldosterone, and EO (1.71 ± 0.77 nmol/l) rose, while urinary EO excretion remained within the normal range (1.44 ± 0.31 nmol/day). Blood pressure fell in one subject during HCTZ. HPLC of the plasma extracts showed one primary peak of EO immunoreactivity with a retention time equivalent to ouabain. High-salt diets and HCTZ raise plasma EO by stimulating EO secretion, and a J-shaped curve relates sodium balance and EO in healthy men. Under normal dietary conditions, ∼98% of the filtered load of EO is reabsorbed by the kidney, and differences in the circulating levels of EO are strongly influenced by secretion and urinary excretion of EO. The dramatic impact of high-salt diets on plasma EO is consistent with its proposed role as a humoral vasoconstrictor that links salt intake with vascular function in hypertension.


2013 ◽  
Vol 33 (6) ◽  
pp. 602-608 ◽  
Author(s):  
MT Olaleye ◽  
OO Crown ◽  
AC Akinmoladun ◽  
AA Akindahunsi

Rutin and quercetin were investigated for their effects on blood pressure and antioxidant defense system of rats fed with 8% sodium chloride-supplemented diet (high salt diet) for 6 weeks. Animals fed with high salt diet demonstrated an increase in systolic, diastolic, pulse, and mean arterial blood pressures ( p < 0.05) as well as lipid peroxidation but decreases in the activities of antioxidant enzymes compared with control group. Groups post-treated with rutin and quercetin for 2 weeks showed significant reversals in the values of these indices compared with the group fed with only the high salt diet but not post-treated. The high salt diet also led to significant increase in serum glucose, urea, creatinine, triglycerides, low-density-lipoprotein, and total cholesterol concentrations. Treatment with rutin and quercetin ameliorated the effects of high salt diet on these biochemical indices. The reference standard, nifedipin was less effective than rutin and quercetin. The results of this study highlight the risk of high salt consumption on cardiovascular health and the potent antioxidant and antihypertensive property of rutin and quercetin.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6807
Author(s):  
Wei Liu ◽  
Danjuan Sui ◽  
Huanying Ye ◽  
Zhen Ouyang ◽  
Yuan Wei

Background Arachidonic acid (AA) is oxidized by cytochrome P450s (CYPs) to form epoxyeicosatrienoic acids (EETs), compounds that modulate ion transport, gene expression, and vasorelaxation. Both CYP2Cs and CYP2Js are involved in kidney EET epoxidation. Methods In this study, we used a CYP2C11-null rat model to explore the in vivo effects of CYP2C11 on vasorelaxation. For 2 months, CYP2C11-null and wild-type (WT) Sprague-Dawley rats were either fed normal lab (0.3% (w/w) sodium chloride) or high-salt (8% (w/w) sodium chloride) diets. Subsequently, an invasive method was used to determine blood pressure. Next, western blots, quantitative PCR, and immunohistochemistry were used to determine renal expression of CYPs involved in AA metabolism. Results Among CYP2C11-null rats, a high-salt diet (females: 156.79 ± 15.89 mm Hg, males: 130.25 ± 16.76 mm Hg, n = 10) resulted in significantly higher blood pressure than a normal diet (females: 118.05 ± 8.43 mm Hg, P < 0.01; males: 115.15 ± 11.45 mm Hg, P < 0.05, n = 10). Compared with WT rats under the high-salt diet, western blots showed that CYP2C11-null rats had higher renal expression of CYP2J2 and CYP4A. This was consistent with the results of immunohistochemistry and the qPCR, respectively. The two rat strains did not differ in the renal expression of CYP2C23 or CYP2C24. Conclusion Our findings suggested that CYP2C11 plays an important role in lowering blood pressure under the challenge of a high-salt diet.


1991 ◽  
Vol 261 (3) ◽  
pp. R595-R602 ◽  
Author(s):  
R. J. Roman ◽  
M. Kaldunski

The present study examined whether alterations in papillary blood flow, renal interstitial pressure (RIHP), and the pressure-natriuretic (PN) response are associated with the development of hypertension in inbred Dahl salt-sensitive (Dahl-S) rats. The PN responses were compared in 18- to 20-wk-old, Inactin-anesthetized, inbred Dahl salt-sensitive (S/Jr) and salt-resistant (R/Jr) rats fed a low-(0.3%) and a high- (8.0%) sodium chloride diet. Cortical and papillary blood flows were measured using laser-Doppler flowmetry. Neural and hormonal influences on the kidney were controlled by renal denervation and by fixing plasma norepinephrine, vasopressin, corticosterone, and aldosterone levels by intravenous infusion. The slope of the PN relationship in S/Jr rats maintained on a low-salt diet was 62% lower than that observed in R/Jr rats; however, whole kidney, cortical, and papillary blood flows and RIHP were not significantly different at any perfusion pressure studied. Glomerular filtration rate (GFR) was 25% lower in S/Jr rats than in R/Jr animals maintained on a low-salt diet. The slopes of the PN responses were similar in S/Jr and R/Jr rats exposed to a high-salt diet, but the entire relationship was shifted toward higher pressures by 20 mmHg in the S/Jr rats. Control cortical and papillary blood flows measured at control mean arterial pressures of 126 +/- 3 and 167 +/- 5 mmHg in R/Jr and S/Jr rats, respectively, were not significantly different. However, cortical and papillary blood flows were 25% lower in the S/Jr than in the R/Jr rats exposed to a high-salt diet when compared at equivalent renal perfusion pressures.(ABSTRACT TRUNCATED AT 250 WORDS)


1991 ◽  
Vol 261 (4) ◽  
pp. R934-R938 ◽  
Author(s):  
M. A. Boegehold ◽  
L. J. Huffman ◽  
G. A. Hedge

The aim of this study was to determine whether different organs undergo similar increases in vascular resistance with hypertension in the Dahl salt-sensitive rat. Cardiac output and organ blood flows were measured with microspheres in anesthetized salt-sensitive and salt-resistant rats fed a high- (7%) or normal- (0.45%) salt diet for 4 wk. High salt intake produced hypertension only in salt-sensitive rats. Cardiac index for the hypertensive group was not different from that for any other group, whereas peripheral resistance index was elevated in proportion to arterial pressure. There were no differences among groups in the fraction of cardiac output supplying the myocardium, intestine, diaphragm, spinotrapezius muscle, or gracilis muscle. The fraction of cardiac output supplying the kidneys was lower in salt-sensitive rats (13%) than in salt-resistant rats (17%) and, among salt-sensitive rats, lowest in the high-salt group. Therefore all the organs studied contribute to increased total peripheral resistance in the hypertensive Dahl rat, with the renal vasculature undergoing the largest resistance increase. Different muscles undergo similar increases in vascular resistance, despite differences in the microvascular abnormalities accompanying salt-induced hypertension.


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