Redistribution of distal tubule Na+-Cl− cotransporter (NCC) in response to a high-salt diet

2006 ◽  
Vol 291 (2) ◽  
pp. F503-F508 ◽  
Author(s):  
Monica B. Sandberg ◽  
Arvid B. Maunsbach ◽  
Alicia A. McDonough
Keyword(s):  
Immunoelectron Microscopy ◽  
Gradient Centrifugation ◽  
Distal Tubule ◽  
High Salt ◽  
Sprague Dawley ◽  
Dietary Salt ◽  
High Salt Diet ◽  
Salt Diet ◽  
Sprague Dawley Rats ◽  
Low Salt

The distal convoluted tubule (DCT) apical Na+-Cl− cotransporter (NCC) is responsible for the reabsorption of 5–10% of filtered NaCl and is the target for thiazide diuretics. NCC abundance is increased during dietary NaCl restriction and by aldosterone and decreased during a high-salt (HS) diet and mineralocorticoid blockade. This study tested the hypothesis that subcellular distribution of NCC is also regulated in response to changes in dietary salt. Six-week-old Sprague-Dawley rats were fed a normal-salt diet (NS; 0.4% NaCl) for 3 wk, then switched to a HS diet (4% NaCl) for 3 wk or a low-salt diet (LS; 0.07% NaCl) for 1 wk. Under anesthesia, kidneys were excised, renal cortex was dissected, and NCC was analyzed with specific antibodies after either 1) density gradient centrifugation followed by immunoblotting or 2) fixation followed by immunoelectron microscopy. The HS diet decreased NCC abundance to 0.50 ± 0.10 of levels in LS diet (1.00 ± 0.23). The HS diet also caused a redistribution of NCC from low to higher density membranes. Immunoelectron microscopy revealed that NCC resides predominantly in the apical membrane in rats fed the LS diet and increases in subapical vesicles in rats fed the HS diet. In conclusion, a HS diet provokes a rapid and persistent redistribution of NCC from apical to subapical membranes, a mechanism that would facilitate a homeostatic decrease in NaCl reabsorption in the DCT to compensate for increased dietary salt.

Effect of high-salt diet on NO release and superoxide production in rat aorta

2004 ◽  
Vol 286 (2) ◽  
pp. H575-H583 ◽  
Author(s):  
Jiaxuan Zhu ◽  
Takefumi Mori ◽  
Tianjian Huang ◽  
Julian H. Lombard
Keyword(s):  
Rat Aorta ◽  
High Salt ◽  
Superoxide Production ◽  
Fluorescence Signal ◽  
Sprague Dawley ◽  
High Salt Diet ◽  
Salt Diet ◽  
Sprague Dawley Rats ◽  
Low Salt ◽  
No Release

Sprague-Dawley rats were fed either a high-salt (HS) diet (4.0% NaCl) or a low-salt (LS) diet (0.4% NaCl) for 3 days. Nitric oxide (NO) and superoxide production were assessed in the thoracic aorta by evaluating the fluorescence signal intensity from 4,5-diaminofluorescein (DAF-2DA) and dihydroethidine, respectively. Methacholine caused increased NO release in the aortas from rats on a LS but not HS diet. The SOD mimetic tempol restored methacholine-induced NO release in aortas from rats on a HS diet. Methacholine also caused superoxide production in the aortas of rats on a HS diet but not in the aortas of rats on a LS diet. Tempol and NG-monomethyl-l-arginine eliminated methacholine-induced superoxide production in the aortas of rats on a HS diet. Aortic rings from rats on the HS diet showed impaired methacholine-induced relaxation, which was improved by tempol. Tempol alone caused a NO-dependent relaxation of norepinephrine-precontracted aortas that was significantly greater in the aortas of rats on the HS diet than in vessels from rats on the LS diet. These data suggest that a HS diet impairs endothelium-dependent relaxation via reduced NO levels and increased superoxide production.

Renal endothelin in chronic angiotensin II hypertension

2002 ◽  
Vol 283 (1) ◽  
pp. R243-R248 ◽  
Author(s):  
Jennifer M. Sasser ◽  
Jennifer S. Pollock ◽  
David M. Pollock
Keyword(s):  
Sodium Intake ◽  
Renal Tissue ◽  
High Salt ◽  
Ang Ii ◽  
Sprague Dawley ◽  
Outer Medulla ◽  
High Salt Diet ◽  
Salt Diet ◽  
Sprague Dawley Rats ◽  
Saline Vehicle

To determine the influence of chronic ANG II infusion on urinary, plasma, and renal tissue levels of immunoreactive endothelin (ET), ANG II (65 ng/min) or saline vehicle was delivered via osmotic minipump in male Sprague-Dawley rats given either a high-salt diet (10% NaCl) or normal-salt diet (0.8% NaCl). High-salt diet alone caused a slight but not statistically significant increase (7 ± 1%) in mean arterial pressure (MAP). MAP was significantly increased in ANG II-infused rats (41 ± 10%), and the increase in MAP was significantly greater in ANG II rats given a high-salt diet (59 ± 1%) compared with the increase observed in rats given a high-salt diet alone or ANG II infusion and normal-salt diet. After a 2-wk treatment, urinary excretion of immunoreactive ET was significantly increased by ∼50% in ANG II-infused animals and by over 250% in rats on high-salt diet, with or without ANG II infusion. ANG II infusion combined with high-salt diet significantly increased immunoreactive ET content in the cortex and outer medulla, but this effect was not observed in other groups. In contrast, high-salt diet, with or without ANG II infusion, significantly decreased immunoreactive ET content within the inner medulla. These data indicate that chronic elevations in ANG II levels and sodium intake differentially affect ET levels within the kidney and provide further support for the hypothesis that the hypertensive effects of ANG II may be due to interaction with the renal ET system.

scholarly journals Aortic Stiffness and Diastolic Dysfunction in Sprague Dawley Rats Consuming Short-Term Fructose Plus High Salt Diet

2020 ◽  
Vol Volume 13 ◽  
pp. 111-124
Author(s):  
Dragana Komnenov ◽  
Peter E Levanovich ◽  
Natalia Perecki ◽  
Charles S Chung ◽  
Noreen F Rossi
Keyword(s):  
Diastolic Dysfunction ◽  
Aortic Stiffness ◽  
High Salt ◽  
Sprague Dawley ◽  
Short Term ◽  
High Salt Diet ◽  
Salt Diet ◽  
Sprague Dawley Rats

Effect of Salt Intake and Potassium Supplementation on Urinary Renalase and Serum Dopamine Levels in Chinese Adults

Cardiology ◽  
2015 ◽  
Vol 130 (4) ◽  
pp. 242-248 ◽  
Author(s):  
Yang Wang ◽  
Dan Wang ◽  
Chao Chu ◽  
Jian-Jun Mu ◽  
Man Wang ◽  
...  
Keyword(s):  
Salt Intake ◽  
High Salt ◽  
Dietary Salt ◽  
High Potassium ◽  
High Salt Diet ◽  
Salt Diet ◽  
Dietary Salt Intake ◽  
Potassium Intake ◽  
Potassium Supplementation ◽  
Low Salt

Objective: The aim of our study was to assess the effects of altered salt and potassium intake on urinary renalase and serum dopamine levels in humans. Methods: Forty-two subjects (28-65 years of age) were selected from a rural community of northern China. All subjects were sequentially maintained on a low-salt diet for 7 days (3.0 g/day of NaCl), a high-salt diet for an additional 7 days (18.0 g/day of NaCl), and a high-salt diet with potassium supplementation for a final 7 days (18.0 g/day of NaCl + 4.5 g/day of KCl). Results: Urinary renalase excretions were significantly higher during the high-salt diet intervention than during the low-salt diet. During high-potassium intake, urinary renalase excretions were not significantly different from the high-salt diet, whereas they were significantly higher than the low-salt levels. Serum dopamine levels exhibited similar trends across the interventions. Additionally, a significant positive relationship was observed between the urine renalase and serum dopamine among the different dietary interventions. Also, 24-hour urinary sodium excretion positively correlated with urine renalase and serum dopamine in the whole population. Conclusions: The present study indicates that dietary salt intake and potassium supplementation increase urinary renalase and serum dopamine levels in Chinese subjects.

scholarly journals Fructose plus High-Salt Diet in Early Life Results in Salt-Sensitive Cardiovascular Changes in Mature Male Sprague Dawley Rats

Nutrients ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 3129
Author(s):  
Peter E. Levanovich ◽  
Charles S. Chung ◽  
Dragana Komnenov ◽  
Noreen F. Rossi
Keyword(s):  
Phase I ◽  
Left Ventricular ◽  
High Salt ◽  
Male Rats ◽  
Phase Iii ◽  
Lv Function ◽  
Sprague Dawley ◽  
High Salt Diet ◽  
Salt Diet ◽  
Sprague Dawley Rats

Fructose and salt intake remain high, particularly in adolescents and young adults. The present studies were designed to evaluate the impact of high fructose and/or salt during pre- and early adolescence on salt sensitivity, blood pressure, arterial compliance, and left ventricular (LV) function in maturity. Male 5-week-old Sprague Dawley rats were studied over three 3-week phases (Phases I, II, and III). Two reference groups received either 20% glucose + 0.4% NaCl (GCS-GCS) or 20% fructose + 4% NaCl (FHS-FHS) throughout this study. The two test groups ingested fructose + 0.4% NaCl (FCS) or FHS during Phase I, then GCS in Phase II, and were then challenged with 20% glucose + 4% NaCl (GHS) in Phase III: FCS-GHS and FHS-GHS, respectively. Compared with GCS-GCS, systolic and mean pressures were significantly higher at the end of Phase III in all groups fed fructose during Phase I. Aortic pulse wave velocity (PWV) was elevated at the end of Phase I in FHS-GHS and FHS-FHS (vs. GCS-GCS). At the end of Phase III, PWV and renal resistive index were higher in FHS-GHS and FHS-FHS vs. GCS-GCS. Diastolic, but not systolic, LV function was impaired in the FHS-GHS and FHS-FHS but not FCS-FHS rats. Consumption of 20% fructose by male rats during adolescence results in salt-sensitive hypertension in maturity. When ingested with a high-salt diet during this early plastic phase, dietary fructose also predisposes to vascular stiffening and LV diastolic dysfunction in later life.

scholarly journals Tubuloglomerular feedback in Dahl rats

1998 ◽  
Vol 274 (6) ◽  
pp. R1561-R1569 ◽  
Author(s):  
Finn M. Karlsen ◽  
Paul P. Leyssac ◽  
Niels-Henrik Holstein-Rathlou
Keyword(s):  
Flow Rate ◽  
Tubuloglomerular Feedback ◽  
Sprague Dawley ◽  
Compensatory Response ◽  
High Salt Diet ◽  
Salt Diet ◽  
Sprague Dawley Rats ◽  
Intratubular Pressure ◽  
Low Salt ◽  
Experimental Rat Model

We have previously demonstrated a loss of autoregulation in Dahl salt-sensitive (Dahl-S) rats rendered hypertensive on a high-salt diet. To determine whether this was due to a decreased activity of either the myogenic or the tubuloglomerular feedback (TGF) response, we tested the TGF response in both Dahl-S and salt-resistant Dahl rats on high- and low-salt diets. TGF was investigated in the closed-loop mode with a videometric technique, in which the response in late proximal flow rate to perturbations in Henle flow rate was measured. All Dahl rats showed a similar compensatory response to perturbations around the natural operating point, with a TGF response that was more efficient than in normotensive Sprague-Dawley rats. No evidence of decreased TGF responsiveness in hypertensive Dahl-S rats was found. The results suggest that the loss of autoregulation in hypertensive Dahl-S rats is due to a compromised myogenic response. We also measured the free-flow proximal intratubular pressure in Dahl rats. Perfectly regular oscillations were demonstrated in all Dahl series, including the hypertensive Dahl-S rats. This is the first demonstration of regular oscillations in an experimental rat model of hypertension.

Relaxation response of abdominal aorta to androgens in orchidectomised Sprague–Dawley rats fed a high-salt diet

2012 ◽  
Vol 90 (12) ◽  
pp. 1647-1651 ◽  
Author(s):  
Ahmed Kolade Oloyo ◽  
Renuka R. Nair ◽  
Chikodi N. Anigbogu ◽  
Olusoga A. Sofola
Keyword(s):  
Abdominal Aorta ◽  
High Salt ◽  
Relaxation Response ◽  
Sprague Dawley ◽  
High Salt Diet ◽  
Salt Diet ◽  
Vasorelaxant Effect ◽  
Sprague Dawley Rats ◽  
The Status ◽  
Gonadal Status

Previous studies have demonstrated the acute relaxant effects of androgens on normal arterial beds, but not on any with underlying or induced pathologies. This study investigated whether the status of the gonads affects the direct actions of androgens on isolated abdominal aorta from male Sprague–Dawley rats fed a high-salt diet. A high-salt diet reduced the relaxation response to exogenous testosterone, but not to dehydroepiandrosterone (DHEA). Orchidectomy reduced the relaxation response to both testosterone and DHEA, while testosterone replacement restored the acute vasorelaxant effect of testosterone and DHEA in both normal and high-salt diet fed rats. Gonadal status appears to be important in the acute vasorelaxant effect of androgens.

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