Influence of a High Salt Diet on Glomerular Injury and the Preventive Effects of Amiloride in Adriamycin Nephropathy

Nephron ◽  
1995 ◽  
Vol 71 (1) ◽  
pp. 87-94 ◽  
Author(s):  
Akinori Nagashima ◽  
Seiya Okuda ◽  
Kiyoshi Tamaki ◽  
Masatoshi Fujishima
2018 ◽  
Vol 132 (11) ◽  
pp. 1179-1197 ◽  
Author(s):  
Sarah C. Ray ◽  
Bansari Patel ◽  
Debra L. Irsik ◽  
Jingping Sun ◽  
Hiram Ocasio ◽  
...  

Sodium bicarbonate (NaHCO3) slows the decline in kidney function in patients with chronic kidney disease (CKD), yet the mechanisms mediating this effect remain unclear. The Dahl salt-sensitive (SS) rat develops hypertension and progressive renal injury when fed a high salt diet; however, the effect of alkali loading on kidney injury has never been investigated in this model. We hypothesized that NaHCO3 protects from the development of renal injury in Dahl salt-sensitive rats via luminal alkalization which limits the formation of tubular casts, which are a prominent pathological feature in this model. To examine this hypothesis, we determined blood pressure and renal injury responses in Dahl SS rats drinking vehicle (0.1 M NaCl) or NaHCO3 (0.1 M) solutions as well as in Dahl SS rats lacking the voltage-gated proton channel (Hv1). We found that oral NaHCO3 reduced tubular NH4+ production, tubular cast formation, and interstitial fibrosis in rats fed a high salt diet for 2 weeks. This effect was independent of changes in blood pressure, glomerular injury, or proteinuria and did not associate with changes in renal inflammatory status. We found that null mutation of Hv1 also limited cast formation in Dahl SS rats independent of proteinuria or glomerular injury. As Hv1 is localized to the luminal membrane of TAL, our data suggest that alkalization of the luminal fluid within this segment limits cast formation in this model. Reduced cast formation, secondary to luminal alkalization within TAL segments may mediate some of the protective effects of alkali loading observed in CKD patients.


2000 ◽  
Vol 11 (1) ◽  
pp. 39-46
Author(s):  
AKINORI HAMAGUCHI ◽  
SHOKEI KIM ◽  
YASUKATSU IZUMI ◽  
HIROSHI IWAO

Abstract. The in vivo role of mitogen-activated protein kinases (MAPK) in the development of glomerular injury is poorly understood. In the present study, glomerular MAPK activities, including extracellular signal-regulated kinases (ERK), c-Jun NH2-terminal kinases (JNK), and transcriptional factor, activator protein-1 (AP-1) were examined in glomerular injury of salt-induced hypertensive rats. Six-week-old Dahl salt-sensitive (Dahl-S) and salt-resistant (Dahl-R) rats were maintained on a high-salt (8.0% NaCl) diet for 1, 5, and 10 wk. In Dahl-S rats, as shown by in-gel kinase assay, an increase in BP by a high-salt diet was followed by chronic activation of glomerular ERK and JNK, which continued until 10 wk after a high-salt diet. Western blot analysis demonstrated a significant increase in the protein expression of glomerular ERK and JNK in Dahl-S rats fed a high-salt diet. As determined by gel-mobility shift assay, ERK and JNK activations were associated with an increase in glomerular AP-1 DNA binding activity. On the other hand, in Dahl-R rats fed a high-salt diet, BP remained normal throughout the experiments. However, glomerular ERK and JNK activities and AP-1 DNA binding activity in Dahl-R rats were not affected by 1 or 5 wk of a high-salt diet, but significantly increased by 10 wk of treatment with a high-salt diet, indicating that chronic sodium overload itself stimulated glomerular ERK and JNK and AP-1 activities. These kinase activations in both Dahl-S and Dahl-R rats were accompanied by an increase in urinary protein excretion and renal growth. These observations provide the first evidence that salt-sensitive hypertension causes chronic activation of glomerular ERK and JNK, probably leading to the activation of AP-1. Thus, glomerular MAPK may be responsible for the development of salt-induced glomerular injury.


Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 463-P
Author(s):  
TOMONORI KIMURA ◽  
YOSHITAKA HASHIMOTO ◽  
TAKAFUMI SENMARU ◽  
EMI USHIGOME ◽  
MASAHIDE HAMAGUCHI ◽  
...  
Keyword(s):  

2019 ◽  
Vol 20 (14) ◽  
pp. 3495 ◽  
Author(s):  
Yanling Yan ◽  
Jiayan Wang ◽  
Muhammad A. Chaudhry ◽  
Ying Nie ◽  
Shuyan Sun ◽  
...  

We have demonstrated that Na/K-ATPase acts as a receptor for reactive oxygen species (ROS), regulating renal Na+ handling and blood pressure. TALLYHO/JngJ (TH) mice are believed to mimic the state of obesity in humans with a polygenic background of type 2 diabetes. This present work is to investigate the role of Na/K-ATPase signaling in TH mice, focusing on susceptibility to hypertension due to chronic excess salt ingestion. Age-matched male TH and the control C57BL/6J (B6) mice were fed either normal diet or high salt diet (HS: 2, 4, and 8% NaCl) to construct the renal function curve. Na/K-ATPase signaling including c-Src and ERK1/2 phosphorylation, as well as protein carbonylation (a commonly used marker for enhanced ROS production), were assessed in the kidney cortex tissues by Western blot. Urinary and plasma Na+ levels were measured by flame photometry. When compared to B6 mice, TH mice developed salt-sensitive hypertension and responded to a high salt diet with a significant rise in systolic blood pressure indicative of a blunted pressure-natriuresis relationship. These findings were evidenced by a decrease in total and fractional Na+ excretion and a right-shifted renal function curve with a reduced slope. This salt-sensitive hypertension correlated with changes in the Na/K-ATPase signaling. Specifically, Na/K-ATPase signaling was not able to be stimulated by HS due to the activated baseline protein carbonylation, phosphorylation of c-Src and ERK1/2. These findings support the emerging view that Na/K-ATPase signaling contributes to metabolic disease and suggest that malfunction of the Na/K-ATPase signaling may promote the development of salt-sensitive hypertension in obesity. The increased basal level of renal Na/K-ATPase-dependent redox signaling may be responsible for the development of salt-sensitive hypertension in polygenic obese TH mice.


Hypertension ◽  
2005 ◽  
Vol 45 (5) ◽  
pp. 853-859 ◽  
Author(s):  
Magdalena Gonzalez ◽  
Lorena Lobos ◽  
Felipe Castillo ◽  
Lorna Galleguillos ◽  
Nandy C. Lopez ◽  
...  

2021 ◽  
pp. 102796
Author(s):  
Bryan K. Becker ◽  
Jermaine G. Johnston ◽  
Carolyn Young ◽  
Alfredo A. Torres Rodriguez ◽  
Chunhua Jin ◽  
...  

2002 ◽  
Vol 282 (2) ◽  
pp. H395-H402 ◽  
Author(s):  
Deborah M. Lenda ◽  
Matthew A. Boegehold

Increased salt intake attenuates the endothelium-dependent dilation of skeletal muscle arterioles by abolishing local nitric oxide (NO) activity. There is evidence of oxidative stress in arteriolar and venular walls of rats fed a high-salt diet, and depressed arteriolar responses to acetylcholine (ACh) in these rats are reversed by scavengers of reactive oxygen species (ROS). In this study, we tested the hypothesis that this salt-dependent increase in microvascular ROS and the resulting attenuation of endothelium-dependent dilation are due to increased expression and/or activity of oxidant enzymes in the microvascular wall. Resting arteriolar and venular wall oxidant activity, as assessed by tetranitroblue tetrazolium reduction, was consistently higher in the spinotrapezius muscle of rats fed a high-salt diet (7% NaCl, HS) for 4–5 wk than in those fed a normal diet (0.45% NaCl, NS) for the same duration. Western analysis of protein from isolated microvessels showed no difference between HS and NS rats in the expression of NAD(P)H oxidase or xanthine oxidase. Inhibition of NAD(P)H oxidase and/or xanthine oxidase with diphenyleneiodonium chloride and oxypurinol, respectively, reduced resting arteriolar wall oxidant activity to normal levels in HS rats but had no effect in NS rats, suggesting that the basal activities of NAD(P)H oxidase and xanthine oxidase are increased in HS microvessels. However, inhibition of these enzymes in HS rats did not restore normal arteriolar responses to ACh, suggesting that this stimulus activates an alternate source of ROS that eliminates the role of NO in the subsequent dilation.


2002 ◽  
Vol 283 (5) ◽  
pp. F1132-F1141 ◽  
Author(s):  
Violeta Alvarez ◽  
Yasmir Quiroz ◽  
Mayerly Nava ◽  
Héctor Pons ◽  
Bernardo Rodríguez-Iturbe

Recent evidence suggests that salt-sensitive hypertension develops as a consequence of renal infiltration with immunocompetent cells. We investigated whether proteinuria, which is known to induce interstitial nephritis, causes salt-sensitive hypertension. Female Lewis rats received 2 g of BSA intraperitoneally daily for 2 wk. After protein overload (PO), 6 wk of a high-salt diet induced hypertension [systolic blood pressure (SBP) = 156 ± 11.8 mmHg], whereas rats that remained on a normal-salt diet and control rats (without PO) on a high-salt diet were normotensive. Administration of mycophenolate mofetil (20 mg · kg−1 · day−1) during PO resulted in prevention of proteinuria-related interstitial nephritis, reduction of renal angiotensin II-positive cells and oxidative stress (superoxide-positive cells and renal malondialdehyde content), and resistance to the hypertensive effect of the high-salt diet (SBP = 129 ± 12.2 mmHg). The present studies support the participation of renal inflammatory infiltrate in the pathogenesis of salt-sensitive hypertension and provide a direct link between two risk factors of progressive renal damage: proteinuria and hypertension.


Sign in / Sign up

Export Citation Format

Share Document