scholarly journals Paternal Long-Term PM2.5 Exposure Causes Hypertension via Increased Renal AT1R Expression and Function in Male Offspring

2021 ◽  
Author(s):  
Cuimei Hu ◽  
Yu Tao ◽  
Yi Deng ◽  
Qi Cai ◽  
Hongmei Ren ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Sodium Excretion ◽  
Tap Water ◽  
Fine Particulate Matter ◽  
Urine Volume ◽  
Male Offspring ◽  
Sprague Dawley ◽  
Pm2.5 Exposure

Maternal exposure to fine particulate matter (PM2.5) causes hypertension in offspring. However, paternal contribution of PM2.5 exposure to hypertension in offspring remains unknown. In the present study, male Sprague-Dawley rats were treated with PM2.5 suspension for 12 weeks and/or fed with tap water containing an antioxidant tempol. The blood pressure, 24 h-urine volume and sodium excretion were determined in male offspring. The offspring were also administrated with losartan for four weeks. The expressions of AT1R and GRK4 were determined. We found that long-term PM2.5 exposure to paternal rats caused hypertension and impaired urine volume and sodium excretion in male offspring. Both the mRNA and protein expression of GRK4 and its downstream target AT1R were increased in offspring of PM2.5-exposed paternal rats, which was reflected in its function because treatment with losartan, an AT1R antagonist, decreased the blood pressure and increased urine volume and sodium excretion. In addition, the oxidative stress level was increased in PM2.5-treated paternal rats. Administration with tempol in paternal rats restored the increased blood pressure and decreased urine volume and sodium excretion in the offspring of PM2.5-exposed paternal rats. Treatment with tempol in paternal rats also reversed the increased expressions of AT1R and GRK4 in the kidney of their offspring. We suggest that paternal PM2.5 exposure causes hypertension in offspring. The mechanism may be involved that paternal PM2.5 exposure-associated oxidative stress induces the elevated renal GRK4 level, leading to the enhanced AT1R expression and its-mediated sodium retention, consequently causes hypertension in male offspring.

scholarly journals In Utero Exposure to Fine Particulate Matter Causes Hypertension Due to Impaired Renal Dopamine D1 Receptor in Offspring

2018 ◽  
Vol 46 (1) ◽  
pp. 148-159 ◽  
Author(s):  
Zhengmeng Ye ◽  
Xi Lu ◽  
Yi Deng ◽  
Xinquan Wang ◽  
Shuo Zheng ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Particulate Matter ◽  
Sodium Excretion ◽  
Fine Particulate Matter ◽  
In Utero ◽  
D1 Receptor ◽  
In Utero Exposure ◽  
Fine Particulate ◽  
Pm2.5 Exposure ◽  
Renal Dopamine

Background/Aims: Adverse environment in utero can modulate adult phenotypes including blood pressure. Fine particulate matter (PM2.5) exposure in utero causes hypertension in the offspring, but the exact mechanisms are not clear. Renal dopamine D1 receptor (D1R), regulated by G protein-coupled receptor kinase type 4 (GRK4), plays an important role in the regulation of renal sodium transport and blood pressure. In this present study, we determined if renal D1R dysfunction is involved in PM2.5–induced hypertension in the offspring. Methods: Pregnant Sprague–Dawley rats were given an oropharyngeal drip of PM2.5 (1.0 mg/kg) at gestation day 8, 10, and 12. The blood pressure, 24-hour sodium excretion, and urine volume were measured in the offspring. The expression levels of GRK4 and D1R were determined by immunoblotting. The phosphorylation of D1R was investigated using immunoprecipitation. Plasma malondialdehyde and superoxide dismutase levels were also measured in the offspring. Results: As compared with saline-treated dams, offspring of PM2.5-treated dams had increased blood pressure, impaired sodium excretion, and reduced D1R-mediated natriuresis and diuresis, accompanied by decreased renal D1R expression and GRK4 expression. The impaired renal D1R function and increased GRK4 expression could be caused by increased reactive oxidative stress (ROS) induced by PM2.5 exposure. Administration of tempol, a redox-cycling nitroxide, for 4 weeks in the offspring of PM2.5-treated dam normalized the decreased renal D1R expression and increased renal D1R phosphorylation and GRK4 expression. Furthermore, tempol normalized the increased renal expression of c-Myc, a transcription factor that regulates GRK4 expression. Conclusions: In utero exposure to PM2.5 increases ROS and GRK4 expression, impairs D1R-mediated sodium excretion, and increases blood pressure in the offspring. These studies suggest that normalization of D1R function may be a target for the prevention and treatment of the hypertension in offspring of mothers exposed to PM2.5 during pregnancy.

scholarly journals Long-Term Effects of Maternal Diabetes on Blood Pressure and Renal Function in Rat Male Offspring

PLoS ONE ◽  
2014 ◽  
Vol 9 (2) ◽  
pp. e88269 ◽  
Author(s):  
Jie Yan ◽  
Xin Li ◽  
Rina Su ◽  
Kai Zhang ◽  
Huixia Yang
Keyword(s):  
Blood Pressure ◽  
Renal Function ◽  
Maternal Diabetes ◽  
Male Offspring ◽  
Long Term Effects

Proximal tubule microvilli remodeling and albuminuria in the Ren2 transgenic rat

2007 ◽  
Vol 292 (2) ◽  
pp. F861-F867 ◽  
Author(s):  
Melvin R. Hayden ◽  
Nazif A. Chowdhury ◽  
Shawna A. Cooper ◽  
Adam Whaley-Connell ◽  
Javad Habibi ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Proximal Tubule ◽  
Structural Damage ◽  
Kidney Tissue ◽  
Proximal Tubule Cell ◽  
Ang Ii ◽  
Sprague Dawley ◽  
Sprague Dawley Rats

TG(mRen2)27 (Ren2) transgenic rats overexpress the mouse renin gene, with subsequent elevated tissue ANG II, hypertension, and nephropathy. The proximal tubule cell (PTC) is responsible for the reabsorption of 5–8 g of glomerular filtered albumin each day. Excess filtered albumin may contribute to PTC damage and tubulointerstitial disease. This investigation examined the role of ANG II-induced oxidative stress in PTC structural remodeling: whether such changes could be modified with in vivo treatment with ANG type 1 receptor (AT1R) blockade (valsartan) or SOD/catalase mimetic (tempol). Male Ren2 (6–7 wk old) and age-matched Sprague-Dawley rats were treated with valsartan (30 mg/kg), tempol (1 mmol/l), or placebo for 3 wk. Systolic blood pressure, albuminuria, N-acetyl-β-d-glucosaminidase, and kidney tissue malondialdehyde (MDA) were measured, and ×60,000 transmission electron microscopy images were used to assess PTC microvilli structure. There were significant differences in systolic blood pressure, albuminuria, lipid peroxidation (MDA and nitrotyrosine staining), and PTC structure in Ren2 vs. Sprague-Dawley rats (each P < 0.05). Increased mean diameter of PTC microvilli in the placebo-treated Ren2 rats ( P < 0.05) correlated strongly with albuminuria ( r2 = 0.83) and moderately with MDA ( r2 = 0.49), and there was an increase in the ratio of abnormal forms of microvilli in placebo-treated Ren2 rats compared with Sprague-Dawley control rats ( P < 0.05). AT1R blockade, but not tempol treatment, abrogated albuminuria and N-acetyl-β-d-glucosaminidase; both therapies corrected abnormalities in oxidative stress and PTC microvilli remodeling. These data indicate that PTC structural damage in the Ren2 rat is related to the oxidative stress response to ANG II and/or albuminuria.

Abstract 16443: Effects of Dietary Salt Intakes on Blood Pressure, Renal Function and Oxidative Stress in Rats Treated With Candesartan

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Gangyi Zhu ◽  
Yanting Yu ◽  
Xiaoyan Wang
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Renal Function ◽  
Kidney Diseases ◽  
Sprague Dawley ◽  
Dietary Salt ◽  
Salt Restriction ◽  
Low Salt ◽  
Receptor Blockers ◽  
And Oxidative Stress

Candesartan is one of angiotensin II type1 receptor blockers(ARB) and commonly used as first-line antihypertensive treatment. Low salt diet is often recommended by clinicians to the patients with hypertension and kidney diseases. However,it is not clear whether salt restriction is beneficial to the patients taking ARB. In order to explore this problem, the impacts of different salt diets on blood pressure (BP),renal function and oxidative stress were determined in 2-3 months old male Sprague Dawley rats treated with candesartan. The rats were randomly divided into 4 groups fed agar-gelled food rationally with NaCl content at 0.01%, 0.8%, 2% and 4% respectively(4-7 rats/group) while all rats were intraperitoneally injected with candesartan at 1mg / kg / day for 7 days. SBP started to decline on day 2 in all except 4% NaCl groups relative to day 0 (recorded 5-6 hrs before the first injection). On day 6, systolic BP (mmHg, tail-cuff, Softron,BP-98A) was lower in 0.8% (103.7+2.3) & 0.01% (101.6+3) groups than 2% (113.5+4.1) & 4% (129.9+4.6) groups (one way ANOVA,LSD test, P<0.05) and correlated positively with food NaCl intakes (R 2 =0.9832). DBP was changed in a similar pattern as SBP. Serum creatinine (μmol/L) was higher in 0.01% group (225+39) than groups of 0.8% (1328+350), 2% (2095+242) and 4% (1576+703) while creatinine clearance (ml/day) was lower in 0.01% group (69.3+9) than groups of 0.8% (43.7+9), 2%(27.7+2) and 4%(29+0.6). In order to determine whether oxidative stress plays any role in the BP regulation and renal function maintenance, we also checked renal protein expression of ROS components. Relative to 0.8% group, renal NOXs were not altered in 0.01% group while NOX1 (145+18,% of 0.8% group), NOX2 (240+54) and NOX4 (197+41) was higher in 2% group than other groups. Mn-SOD (77+7.8), not Cu-Zn SOD, was decreased while HO1 (170+16), not HO2, was increased in 0.01% group. Renal abundance of nitrotyrosine was lower in 0.01% than other groups indicating a decreased oxidative stress, possibly caused by increase in HO1. We concluded that salt restriction with candesartan is beneficial to antihypertensive effect of AT1R blockade but disadvantage to maintenance of renal function. Thus, cautions to choice of low salt intakes are necessary when taking ARB agents.

Abstract 114: K+ Rich Diet During Angiotensin II Hypertension Reduces Renal Na-Cl Cotransporter and Phosphorylation, but Not Blood Pressure

Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Luciana C Veiras ◽  
Jiyang Han ◽  
Donna L Ralph ◽  
Alicia A McDonough
Keyword(s):  
Blood Pressure ◽  
Urine Volume ◽  
Weight Ratio ◽  
Distal Tubule ◽  
Reduce Blood Pressure ◽  
Ang Ii ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
K Secretion ◽  
Pressure Natriuresis

During Ang II hypertension distal tubule Na-Cl Cotransporter (NCC) abundance and its activating phosphorylation (NCCp), as well as Epithelial Na+ channels (ENaC) abundance and activating cleavage are increased 1.5-3 fold. Fasting plasma [K+] is significantly lower in Ang II hypertension (3.3 ± 0.1 mM) versus controls (4.0 ± 0.1 mM), likely secondary to ENaC stimulation driving K+ secretion. The aim of this study was to test the hypothesis that doubling dietary K+ intake during Ang II infusion will lower NCC and NCCp abundance to increase Na+ delivery to ENaC to drive K+ excretion and reduce blood pressure. Methods: Male Sprague Dawley rats (225-250 g; n= 7-9/group) were treated over 2 weeks: 1) Control 1% K diet fed (C1K); 2) Ang II infused (400 ng/kg/min) 1% K diet fed (A1K); or 3) Ang II infused 2% K diet fed (A2K). Blood pressure (BP) was determined by tail cuff, electrolytes by flame photometry and transporters’ abundance by immunoblot of cortical homogenates. Results: As previously reported, Ang II infusion increased systolic BP (from 132 ± 5 to 197 ± 4 mmHg), urine volume (UV, 2.4 fold), urine Na+ (UNaV, 1.3 fold), heart /body weight ratio (1.23 fold) and clearance of endogenous Li+ (CLi, measures fluid volume leaving the proximal tubule, from 0.26 ± 0.02 to 0.51 ± 0.01 ml/min/kg) all evidence for pressure natriuresis. A2K rats exhibited normal plasma [K+] (4.6 ± 0.1 mM, unfasted), doubled urine K+ (UKV, from 0.20 to 0.44 mmol/hr), and increased CLi (to 0.8 ± 0.1 ml/min/kg) but UV, UNaV, cardiac hypertrophy and BP were unchanged versus the A1K group. As expected, NCC, NCCpS71 and NCCpT53 abundance increased in the A1K group to 1.5 ± 0.1, 2.9 ± 0.5 and 2.8 ± 0.4 fold versus C1K, respectively. As predicted by our hypothesis, when dietary K+ was doubled (A2K), Ang II infusion did not activate NCC, NCCpS71 nor NCCpT53 (0.91 ± 0.04, 1.3 ± 0.1 and 1.6 ± 0.2 fold versus C1K, respectively). ENaC subunit abundance and cleavage increased 1.5 to 3 fold in both A1K and A2K groups; ROMK was unaffected by Ang II or dietary K. In conclusion, evidence is presented that stimulation of NCC during Ang II hypertension is secondary to K+ deficiency driven by ENaC stimulation since doubling dietary K+ prevents the activation. The results also indicate that elevation in BP is independent of NCC activation

Angiotensin II-mediated biphasic regulation of proximal tubular Na+/H+ exchanger 3 is impaired during oxidative stress

2011 ◽  
Vol 301 (2) ◽  
pp. F364-F370 ◽  
Author(s):  
Anees Ahmad Banday ◽  
Mustafa F. Lokhandwala
Keyword(s):  
Oxidative Stress ◽  
Protein Kinase ◽  
Tap Water ◽  
Buthionine Sulfoximine ◽  
Inhibitory Effect ◽  
Ang Ii ◽  
Sprague Dawley ◽  
High Concentration ◽  
Nitric Oxide Signaling ◽  
Proximal Tubular

Angiotensin (ANG) II via AT1 receptors (AT1Rs) maintains sodium homeostasis by regulating renal sodium transporters including Na+/H+ exchanger 3 (NHE3) in a biphasic manner. Low-ANG II concentration stimulates whereas high concentrations inhibit NHE3 activity. Oxidative stress has been shown to upregulate AT1R function that could modulate the ANG II-mediated NHE3 regulation. This study was designed to identify the signaling pathways responsible for ANG II-mediated biphasic regulation of proximal tubular NHE3 and the effect of oxidative stress on this phenomenon. Male Sprague-Dawley rats were chronically treated with a pro-oxidant l-buthionine sulfoximine (BSO) with and without an antioxidant tempol in tap water for 3 wk. BSO-treated rats exhibited oxidative stress and high blood pressure. At low concentration (1 pM) ANG II increased NHE3 activity in proximal tubules from all animals. However, in BSO-treated rats, the stimulation was more robust and was normalized by tempol treatment. ANG II (1 pM)-mediated NHE3 activation was abolished by AT1R blocker, intracellular Ca2+ chelator, and inhibitors of phospholipase C (PLC) and Ca2+-dependent calmodulin (CaM) but it was insensitive to Giα and protein kinase C inhibitors or AT2R antagonist. A high concentration of ANG II (1 μM) inhibited NHE3 activity in control and tempol-treated rats. However, in BSO-treated rats, ANG II (1 μM) continued to induce NHE3 stimulation. Tempol restored the inhibitory effect of ANG II (1 μM) in BSO-treated rats. The inhibitory effect of ANG II (1 μM) involved AT1R-dependent, cGMP-dependent protein kinase (PKG) activation and was independent of AT2 receptor and nitric oxide signaling. We conclude that ANG II stimulates NHE3 via AT1R-PLC-CaM pathway and inhibits NHE3 by AT1R-PKG activation. Oxidative stress impaired ANG II-mediated NHE3 biphasic response in that stimulation was observed at both high- and low-ANG II concentration.

Increased renal α-ENaC and NCC abundance and elevated blood pressure are independent of hyperaldosteronism in vasopressin escape

2006 ◽  
Vol 291 (1) ◽  
pp. F49-F57 ◽  
Author(s):  
Swasti Tiwari ◽  
Randall K. Packer ◽  
Xinqun Hu ◽  
Yoshihisa Sugimura ◽  
Joseph G. Verbalis ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Urine Volume ◽  
Sprague Dawley ◽  
Α Subunit ◽  
Water Load ◽  
Arterial Blood ◽  
Sprague Dawley Rats ◽  
Solid Diet ◽  
Epithelial Sodium Channel Enac

Previously, we demonstrated that rats undergoing vasopressin escape had increased mean arterial blood pressure (MAP), plasma and urine aldosterone, and increased renal protein abundance of the α-subunit of the epithelial sodium channel (ENaC), the thiazide-sensitive Na-Cl cotransporter (NCC), and the 70-kDa band of γ-ENaC (Song J, Hu X, Khan O, Tian Y, Verbalis JG, and Ecelbarger CA. Am J Physiol Renal Physiol 287: F1076–F1083, 2004; Ecelbarger CA, Knepper MA, and Verbalis JG. J Am Soc Nephrol 12: 207–217, 2001). Here, we determine whether changes in these renal proteins and MAP require elevated aldosterone levels. We performed adrenalectomies (ADX) or sham surgeries on male Sprague-Dawley rats. Corticosterone and aldosterone were replaced to clamp these hormone levels. MAP was monitored by radiotelemetry. Rats were infused with 1-deamino-[8-d-arginine]-vasopressin (dDAVP) via osmotic minipumps (5 ng/h). At day 3 of dDAVP infusion, seven rats in each group were offered a liquid diet [water load (WL)] or continued on a solid diet (SD). Plasma aldosterone and corticosterone and urine aldosterone were increased by WL in sham rats. ADX-WL rats escaped, as assessed by early natriuresis followed by diuresis; however, urine volume and natriuresis were somewhat blunted. WL did not reduce the abundance or activity of 11-β-hydroxsteroid dehydrogenase type 2. Furthermore, the previously observed increase in renal aldosterone-sensitive proteins and escape-associated increased MAP persisted in clamped rats. The densitometry of immunoblots for NCC, α- and γ-70 kDa ENaC, respectively, were (% sham-SD): sham-WL, 159, 278, 233; ADX-SD, 69, 212, 171; ADX-WL, 116, 302, 161. However, clamping corticosteroids blunted the rise at least for NCC and γ-ENaC (70 kDa). Overall, the increase in aldosterone observed in vasopressin escape is not necessary for the increased expression of NCC, α- or γ-ENaC or increased MAP associated with “escape.”

Abstract P053: Enhanced Exercise Capacity By Muscadine Grape Extract Treatment Is Only Evident In Older Hypertensive Female Rats And Is Independent Of Blood Pressure

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Nildris Cruz Diaz ◽  
A'ja V Duncan ◽  
Wayne Graham ◽  
Brian Westwood ◽  
Patricia E. Gallagher ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Exercise Capacity ◽  
Physical Performance ◽  
Term Treatment ◽  
Female Rats ◽  
Sprague Dawley ◽  
Grape Extract ◽  
Long Term Treatment ◽  
Muscadine Grape

Physical performance and systolic blood pressure (SBP) during aging in normotensive female Sprague-Dawley (SD) and hypertensive (mRen2)27 transgenic rats were assessed following long-term treatment with a Muscadine Grape Extract (MGE, Piedmont Research and Development Corp). MGE was administered at a dose of 0.2 mg/mL in the drinking water starting at 14 weeks (wks) of age with an endpoint at 70 wks of age (total time of treatment of 56 wks). At 20-, 40- and 70-wks of age, physical performance (exercise capacity in seconds and workload in grams - meters) was determined using a treadmill at a velocity of 17 cm/second with a 5% incline. SBP was determined by tail-cuff plethysmography in trained rats. There were no significant differences in physical performance between SD and (mRen2)27 female rats at any age despite the higher SBP in the (mRen2)27 rats at all ages. Long-term treatment with MGE had no significant effect on physical performance or SBP in SD rats at any age. In contrast, MGE treatment markedly increased exercise capacity (40 wks: 1615 ± 166 vs 4943 ± 442 seconds, p<0.01, n = 4-9; 70 wks: 2520 ± 374 vs 4117 ± 245 seconds, p<0.01, n = 4-8) and workload (40 wks: 4579 ± 490 vs 14730 ± 1353 grams - meters, p<0.01, n = 4-9; 70 wks: 8338 ± 1340 vs 13659 ± 933 grams - meters, p<0.01, n = 4-8) at the later ages in female (mRen2)27 rats, while there was no effect on SBP (20 wks: 167 ± 4 vs 173 ± 4 mm Hg, n = 4-6; 40 wks: 177 ± 8 vs 170 ± 7 mm Hg, n = 6-7; 70 wks:154 ± 6 vs 172 ± 6 mm Hg, n = 5) at any age. These data suggest that MGE treatment is effective in improving physical performance only in hypertensive female rats and may be independent of changes in blood pressure. The benefit of MGE in the older hypertensive female may reflect reductions in vascular stiffness and oxidative stress. Support: Chronic Disease Research Fund, Hypertension & Vascular Research Center

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