scholarly journals Effect of high-salt diet on mean arterial pressure, renal epithelial sodium channels and aquaporin subunits expression levels in Spontaneously Hypertensive Rats

2019 ◽  
Author(s):  
Chitra Devi Ramachandran ◽  
Khadijeh Gholami ◽  
Sau-Kuen Lam ◽  
Mohd Rais Mustafa ◽  
See-Ziau Hoe
Keyword(s):  
Protein Expression ◽  
Fluid Intake ◽  
High Salt ◽  
High Salt Diet ◽  
Salt Diet ◽  
Spontaneously Hypertensive ◽  
Expression Levels ◽  
Protein Levels ◽  
Wky Rats ◽  
Mrna And Protein Expression

AbstractAn increase in blood pressure (BP) by a high-salt (HS) diet may involve the changes in the expression of epithelium sodium channels (ENaCs) and aquaporins (AQPs) in the kidney which affect the sodium- and water-handling mechanisms. In the present study, spontaneously hypertensive rats (SHRs) and Wistar Kyoto (WKY) rats were exposed to HS and regular-salt (RS) diets for 6 weeks and fluid intake was monitored. After 6 weeks, mean arterial pressure (MAP) and plasma hormonal activity of atrial natriuretic peptide (ANP), levels of angiotensin II (Ang II), aldosterone and arginine vasopressin (AVP) were determined. The expression of mRNA and protein levels of ENaC and AQP subunits in kidneys were quantified by real-time PCR and Western blotting. High-salt diet caused higher MAP only in SHRs and higher fluid intake in both strains of rats when compared with their respective controls on RS diet. The plasma levels of Ang II and aldosterone were low in both SHRs and WKY rats fed with HS diet. Meanwhile, plasma ANP activity was high in both strains of rats on HS diet; whilst the AVP showed vice versa effects. The renal expression of mRNA and protein levels of α- and γ-ENaCs was lowered by HS diet in both SHRs and WKY rats. Although β-ENaC mRNA and protein expression levels were depressed in SHRs but they were enhanced in WKY rats. On the other hand, AQP-1, 2 and 7 mRNA and protein expression levels were lowered in both strains of rats fed with HS diet, while that of AQP-3, 4 and 6 showed no significant changes. The suppression of mRNA and protein expression levels of ENaC and AQP subunits suggests that the HS-induced increase in the MAP of SHRs may not be due to the renal sodium and water retention solely.

Abstract 376: The Expression of (pro)renin Receptor is Upregulated in the Kidney by High Salt Diet and No Inhibition

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Rong Rong ◽  
Osamu Ito ◽  
Nobuyoshi Mori ◽  
Yuma Tamura ◽  
Akihiro Sakuyama ◽  
...  
Keyword(s):  
Collecting Duct ◽  
High Salt ◽  
Kidney Cortex ◽  
Control Group ◽  
Thick Ascending Limb ◽  
High Salt Diet ◽  
Salt Diet ◽  
Protein Levels ◽  
Nephron Segments ◽  
Sd Rats

The (pro)renin receptor ((P)RR)-bound (pro)renin not only causes the generation of angiotensin II via the increased enzymatic activity, it also activates the receptor’s own intracellular signaling pathways up-regulating the expression of the profibrotic proteins. To clarify the regulation of (P)RR expression, the present study examined the effects of high salt diet and nitric oxide synthase (NOS) inhibition on the (P)RR expression in the kidney. The nephron segments were isolated from male Sprague-Dawley (SD) rats by microdissection and bulk isolation technique, and the (P)RR mRNA and protein expressions were examined by using reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis. In adiition, 5 week-old, male SD rats were randomly divided into 3 groups: a control group, a high salt diet (HS) group and a Nω-Nitro-L-arginine (L-NAME) group, and each group was treated with vehicle, high salt diet (8%, NaCl), or L-NAME (600mg/ml in drinking water), respectively. After 4 weeks, the (P)RR expression in the kidney was compared among these groups. The (P)RR mRNA was expressed in the glomerulus (Glm), the proximal convoluted and straight tubule, the cortical and medullary thick ascending limb (TAL) and collecting duct. The (P)RR protein as well as mRNA was expressed widely in the nephron segments; the preglomerular arteriole, the Glm, the proximal tubules (PT), the medullary TAL (mTAL) and inner medullary collecting duct (IMCD). Compared with the control group, the (P)RR protein levels significantly increased in the kidney cortex of both HS group and L-NAME group by 96% (p<0.01) and 506% (p<0.01) and in the inner medulla of L-NAME group by 148% (p<0.05), but did not significantly change in the outer medulla of HS group or L-NAME group. HS increased the (P)RR protein levels in the Glm and PT by 48% (p<0.05) and 39% (p<0.01), but did not affect them in other nephron segments. These results indicated that (P)RR is expressed widely in the nephron segments and that HS and NOS inhibition upregulate the (P)RR expression in the kidney, suggesting roles of (P)RR in hypertensive kidney disorder.

Abstract 370: Upregulation of Renal D5 Dopamine Receptor Ameliorates Hypertension in D3 Deficient Mice

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Xiaoyan Wang ◽  
Crisanto S Escano ◽  
Laureano Asico ◽  
John E Jones ◽  
Alan Barte ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Nadph Oxidase ◽  
Protein Expression ◽  
Dopamine Receptors ◽  
Dopamine Receptor ◽  
High Salt ◽  
High Salt Diet ◽  
Salt Diet ◽  
Deficient Mice

D 3 dopamine receptor (D 3 R) deficient mice have renin-dependent hypertension but the hypertension is mild and is not associated with oxidative stress. In order to determine if any compensatory mechanism in the kidney is involved in the regulation of blood pressure with disruption of D 3 R, we measured the renal protein expression of dopamine receptors in D 3 R homozygous (D 3 -/-) and heterozygous (D 3 +/-) knockout mice and their wild type (D 3 +/+) littermates. D 5 dopamine receptor (D 5 R) (169±23%, reported as % of D 3 +/+, n=5/group) expression was increased but D 4 dopamine receptors protein expression (59±8%) was decreased, while no significant changes were found with D 1 and D 2 dopamine receptors. Immunocytochemistry showed a stronger renal staining of D 5 R but without a change in renal tubule cell distribution in D 3 -/- relative to D 3 +/+ mice. D 5 R abundance was also increased in D 3 +/- (205±30%, n=5/group) relative to D 3 +/+ mice, while D 1 R abundance was similar between D 3 +/- and D 3 +/+ mice. The increase in D 5 R expression was abolished while blood pressure was increased further in D 3 -/- mice fed a high salt diet. Treatment of the D 1 -like (including D 1 and D 5 receptors) antagonist, SCH23390 , increased the blood pressure to a greater extent in anesthetized D 3 -/- mice than in D 3 +/+ mice (n=4/group), suggesting that the upregulation of D 5 R may modulate the hypertension in mice caused by the disruption of D 3 R. Since dopamine inhibits the NADPH oxidase-induced production of reactive oxygen species (ROS) via the D 5 R, we also measured the protein expression of NOXs in the kidney and isoprostane in the urine. No NADPH oxidase subunit was increased in D 3 -/- and D 3 +/- mice relative to D 3 +/+ mice fed a normal or salt high salt diet, and urinary isoprostane excretion was also similar in D 3 -/- and D 3 +/+ mice. Our findings suggest that the upregulation of D 5 R may minimize the hypertension and prevent oxidative stress in D 3 -/- mice.

Response of resistance arteries to reduced PO2 and vasodilators during hypertension and elevated salt intake

1997 ◽  
Vol 273 (2) ◽  
pp. H869-H877 ◽  
Author(s):  
Y. Liu ◽  
K. T. Fredricks ◽  
R. J. Roman ◽  
J. H. Lombard
Keyword(s):  
Skeletal Muscle ◽  
Salt Intake ◽  
High Salt ◽  
Nitric Oxide Donor ◽  
Resistance Arteries ◽  
Hypertensive Rats ◽  
High Salt Diet ◽  
Membrane Function ◽  
Salt Diet ◽  
Spontaneously Hypertensive

This study assessed vasodilator responses in skeletal muscle resistance arteries (100-250 microns) from rats with chronic (4-8 wk) reduced renal mass (RRM) hypertension and normotensive sham-operated controls on a high (4% NaCl; HSSHAM)- or low (0.4% NaCl; LSSHAM)-salt diet. Arteries from RRM hypertensive rats [normal and high-salt diet (HSRRM)] and a separate group of spontaneously hypertensive rats exhibited an impaired dilation in response to reduced PO2 compared with those of their normotensive controls. Prostacyclin release, assessed by radio-immunoassay for 6-ketoprostaglandin F1 alpha, increased significantly in response to reduced PO2, but was unaffected by hypertension or salt intake. Dilator responses to acetylcholine and the prostacyclin analog iloprost were significantly reduced in both HSRRM and HSSHAM compared with LSSHAM rats. Dilation in response to direct activation of adenylate cyclase with forskolin or guanylate cyclase with the nitric oxide donor sodium nitroprusside was not significantly different in HSRRM, HSSHAM, and LSSHAM rats. These results indicate that hypoxic dilation is impaired in skeletal muscle resistance arteries of hypertensive rats and that chronic high-salt diet alone leads to impaired vasodilator responses in resistance arteries of normotensive animals, possibly via abnormalities in membrane function or G protein signaling rather than impaired second-messenger function.

Effects of a chronic high-salt diet on large artery structure: role of endogenous bradykinin

1998 ◽  
Vol 274 (5) ◽  
pp. H1423-H1428 ◽  
Author(s):  
Chohreh Partovian ◽  
Athanase Benetos ◽  
Jean-Pierre Pommiès ◽  
Willy Mischler ◽  
Michel E. Safar
Keyword(s):  
Blood Pressure ◽  
High Salt ◽  
Large Artery ◽  
High Salt Diet ◽  
Salt Diet ◽  
Wky Rats ◽  
Arterial Blood ◽  
Arterial Structure ◽  
Hoe 140

Bradykinin activity could explain the blood pressure increase during NaCl loading in hypertensive animals, but its contribution on vascular structure was not evaluated. We determined cardiac mass and large artery structure after a chronic, 4-mo, high-salt diet in combination with bradykinin B2-receptor blockade by Hoe-140. Four-week-old rats were divided into eight groups according to strain [spontaneously hypertensive rats (SHR) vs. Wistar-Kyoto (WKY) rats], diet (0.4 vs. 7% NaCl), and treatment (Hoe-140 vs. placebo). In WKY rats, a high-salt diet significantly increased intra-arterial blood pressure with minor changes in arterial structure independently of Hoe-140. In SHR, blood pressure remained stable but 1) the high-salt diet was significantly associated with cardiovascular hypertrophy and increased arterial elastin and collagen, and 2) Hoe-140 alone induced carotid hypertrophy. A high-salt diet plus Hoe-140 acted synergistically on carotid hypertrophy and elastin content in SHR, suggesting that the role of endogenous bradykinin on arterial structure was amplified in the presence of a high-salt diet.

scholarly journals Yiqi Huoxue Recipe Improves Liver Regeneration in Rats after Partial Hepatectomy via JNK Pathway

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Wen-cong Li ◽  
Su-xian Zhao ◽  
Wei-guang Ren ◽  
Hui-juan Du ◽  
Yu-guo Zhang ◽  
...  
Keyword(s):  
Protein Expression ◽  
Liver Regeneration ◽  
Partial Hepatectomy ◽  
Underlying Mechanism ◽  
Mrna Levels ◽  
Protective Effects ◽  
Jnk Pathway ◽  
Expression Levels ◽  
Protein Levels ◽  
Mrna And Protein Expression

The liver is the only visceral organ that exhibits a remarkable capability of regenerating in response to partial hepatectomy (PH) or chemical injury. Improving liver regeneration (LR) ability is the basis for the favourable treatment outcome of patients after PH, which can serve as a potential indicator for postoperative survival. The present study aimed to investigate the protective effects of Yiqi Huoxue recipe (YQHX) on LR after PH in rats and further elucidate its underlying mechanism. A two-thirds PH rat model was used in this study. Wistar rats were randomly divided into four groups: sham-operated, PH, YQHX + PH, and Fuzheng Huayu decoction (FZHY) + PH groups. All rats were sacrificed under anesthesia at 24 and 72 h after surgery. The rates of LR were calculated, and the expression levels of cyclin D1 and c-jun were determined by immunohistochemical staining. The protein levels of p-JNK1/2, JNK1/2, p-c-jun, c-jun, Bax, and Bcl-2 were detected by Western blotting, while the mRNA levels of JNK1, JNK2, c-jun, Bax, and Bcl-2 were examined by real-time polymerase chain reaction (RT-PCR). At the corresponding time points, YQHX and FZHY administration dramatically induced the protein levels of p-JNK1/2 compared to the PH group p<0.05, while FZHY + PH group showed prominently increase in p-JNK1/2 protein levels compared to the YQHX + PH group p<0.05. A similar trend was observed for the expression levels of p-c-jun. Compared to the PH group, YQHX and FZHY markedly reduced the mRNA and protein expression levels of Bax at 24 h after PH, while those in the FZHY + PH group decreased more obviously p<0.05. Besides, in comparison with the PH group, YQHX and FZHY administration predominantly upregulated the mRNA and protein expression levels of Bcl-2 at 24 and 72 h after PH p<0.05. In conclusion, YQHX improves LR in rats after PH by inhibiting hepatocyte apoptosis via the JNK signaling pathway.

Effect of long-term consumption of a diet with a high sodium chloride content on microRNA expression in blood serum and urine of Cynomolgus Macaques

2021 ◽  
Vol 25 (4) ◽  
pp. 82-89
Author(s):  
O. N. Beresneva ◽  
M. M. Parastaeva ◽  
M. I. Zaraiski ◽  
Mohamad Khasun ◽  
A. G. Kucher
Keyword(s):  
Blood Serum ◽  
Soy Protein ◽  
High Salt ◽  
Soy Proteins ◽  
Control Group ◽  
Table Salt ◽  
High Salt Diet ◽  
Salt Diet ◽  
Expression Levels ◽  
Cynomolgus Macaques

INTRODUCTION. A high intake of sodium chloride from food is associated with damage not only to the cardiovascular system but also to the kidneys. The mechanisms of the negative effects of high-salt diets on the kidneys have not been established. One of the important links in this process can be microRNAs, which can modulate gene expression at the post-transcriptional level. It is also not known whether soy proteins can counter the kidney remodeling associated with increased salt intake.THE AIM. To estimate the expression levels of miRNA-133 and 203 in blood serum and urine and miRNA-21 in the urine of cynomolgus macaques received diets for a long time with various table salt contents, including and not including soy proteins.MATERIALS AND METHODS. Three groups (6 individuals in each) of male cynomolgus macaques at the age of 6–8 years were studied. The first group (control) received a standard diet, the second – a diet with a high content of table salt (8 g NaCl / kg feed), the third – a diet with high salt content in combination with SUPRO 760 soy protein (200 g protein/kg feed). Blood pressure was measured in animals 12 months later. In monkey urine, the relative expression levels of miRNA-21, miRNA-133, and miRNA-203 were determined, in blood serum – the expression levels of miRNA-133 and miRNA-203.RESULTS. During the follow-up period in the control group, there were no significant changes in the studied parameters. In the groups that received high-salt diets throughout the year, blood pressure also did not change significantly. There was no change in the level of expression of miRNA-133 in the blood serum of monkeys fed a high-salt diet and a standard protein diet. However, in macaques fed a diet high in salt in combination with soy protein, the serum expression of this miRNA was significantly reduced. The expression of miRNA-203 in blood serum did not change significantly. In the control group, there were no changes in the expression of miRNA-21 in urine. In the other two samples, this parameter increased in comparison with the initial values. Both high-salt diets resulted in a significant increase in the relative level of miRNA-133 expression in urine compared to basal values. However, the increase in this indicator in the group of animals fed a high-salt diet in combination with soy isolate was significantly less than in monkeys fed only a high-salt diet. Expression of miRNA-203 in urine was significantly increased only in the group with a high content of table salt without added soy protein.CONCLUSIONS. It is possible that the effects of high-salt diets on the kidney may be mediated by epigenomic mechanisms and partially modulated by the inclusion of isolated soy proteins in the diet.

Enhanced expression of epithelial sodium channels in the renal medulla of Dahl S rats

2011 ◽  
Vol 89 (3) ◽  
pp. 159-168 ◽  
Author(s):  
Md. Shahrier Amin ◽  
Erona Reza ◽  
Esraa El-Shahat ◽  
Hong-Wei Wang ◽  
Frédérique Tesson ◽  
...  
Keyword(s):  
Collecting Duct ◽  
Young Male ◽  
Renal Medulla ◽  
High Salt ◽  
High Salt Diet ◽  
Salt Diet ◽  
Enhanced Expression ◽  
Mrna And Protein Expression ◽  
Medullary Collecting Duct ◽  
Apical Localization

Inner medullary collecting duct (IMCD) cells from salt-sensitive (S) Dahl rats transport twice as much Na+ as cells from salt-resistant (R) rats, possibly related to dysregulation of the renal epithelial sodium channel (ENaC). The effect of a high-salt diet on ENaC expression in the inner medulla of S versus R rats has not yet been studied. Young, male S and R rats were placed on a regular-salt (0.3%) or high-salt (8%) diet for 2 or 4 weeks. mRNA and protein expression of ENaC subunits were studied by real-time PCR and immunoblotting. Intracellular distribution of the subunits in the IMCD was evaluated by immunohistochemistry. On regular salt, the abundance of the mRNA of β and γENaC was higher in the medulla of S rats than R rats. This was associated with a greater protein abundance of 90 kDa γENaC and higher immunoreactivity for both α and γ ENaC. High salt did not affect mRNA abundance in either strain and decreased apical staining of βENaC in IMCD of R rats. In contrast, high salt did not affect the higher apical localization of αENaC and increased the apical membrane staining for β and γENaC in the IMCD of S rats. Expression of ENaC subunits is enhanced in the medulla of S vs. R rats on regular salt, and further increased on high salt. The persistent high expression of αENaC and increase in apical localization of β and γENaC may contribute to greater retention of sodium in S rats on a high-salt diet.

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