scholarly journals Chronic Consumption of a Commercial Energy Drink Reduces Blood Pressure in Normotensive Wild-Type Mice

2019 ◽  
Vol 6 ◽  
Author(s):  
Liam Graneri ◽  
Zachary D'Alonzo ◽  
Virginie Lam ◽  
John Mamo ◽  
Satvinder Dhaliwal ◽  
...  
2008 ◽  
Vol 295 (4) ◽  
pp. F1230-F1238 ◽  
Author(s):  
Soo Mi Kim ◽  
Christoph Eisner ◽  
Robert Faulhaber-Walter ◽  
Diane Mizel ◽  
Susan M. Wall ◽  
...  

NKCC1 is a widely expressed isoform of the Na-2Cl-K cotransporter that mediates several direct and indirect vascular effects and regulates expression and release of renin. In this study, we used NKCC1-deficient (NKCC1−/−) and wild-type (WT) mice to assess day/night differences of blood pressure (BP), locomotor activity, and renin release and to study the effects of high (8%) or low (0.03%) dietary NaCl intake on BP, activity, and the renin/aldosterone system. On a standard diet, 24-h mean arterial blood pressure (MAP) and heart rate determined by radiotelemetry, and their day/night differences, were not different in NKCC1−/− and WT mice. Spontaneous and wheel-running activities in the active night phase were lower in NKCC1−/− than WT mice. In NKCC1−/− mice on a high-NaCl diet, MAP increased by 10 mmHg in the night without changes in heart rate. In contrast, there was no salt-dependent blood pressure change in WT mice. MAP reductions by hydralazine (1 mg/kg) or isoproterenol (10 μg/mouse) were significantly greater in NKCC1−/− than WT mice. Plasma renin (PRC; ng ANG I·ml−1·h−1) and aldosterone (aldo; pg/ml) concentrations were higher in NKCC1−/− than WT mice (PRC: 3,745 ± 377 vs. 1,245 ± 364; aldo: 763 ± 136 vs. 327 ± 98). Hyperreninism and hyperaldosteronism were found in NKCC1−/− mice during both day and night. High Na suppressed PRC and aldosterone in both NKCC1−/− and WT mice, whereas a low-Na diet increased PRC and aldosterone in WT but not NKCC1−/− mice. We conclude that 24-h MAP and MAP circadian rhythms do not differ between NKCC1−/− and WT mice on a standard diet, probably reflecting a balance between anti- and prohypertensive factors, but that blood pressure of NKCC1−/− mice is more sensitive to increases and decreases of Na intake.


2010 ◽  
Vol 38 (1) ◽  
pp. 107-117 ◽  
Author(s):  
Stephanie L. Ballard ◽  
Jennifer J. Wellborn-Kim ◽  
Kevin A. Clauson

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Chrysan J Mohammed ◽  
Fatimah K Khalaf ◽  
Prabhatchandra Dube ◽  
Tyler J Reid ◽  
Jacob A Connolly ◽  
...  

Background: Paraoxonase 3 (Pon3), is one of the three isoforms of the paraoxonase gene family. While Pon1 and Pon2 are widely studied, there is a paucity of knowledge regarding Pon3. Pon3 is synthesized in the liver and can circulate bound to high-density lipoproteins. There is significant expression in the kidney also. Pon3 has the ability to metabolize eicosanoids, which can act as signaling molecules and have known roles in the pathophysiology of some renal diseases. Decreased Pon activity is associated with elevated levels of eicosanoid metabolites and adverse clinical outcomes. We tested the hypothesis that targeted disruption of Pon3 results in elevated levels of pro-inflammatory eicosanoids and progression of renal injury. Methods/ Results: Ten week old male Dahl salt-sensitive (SS rats) and Pon3 mutant rats (SS Pon3 KO) were maintained on 8% high salt diet for eight weeks, to initiate salt-sensitive hypertensive renal disease. Previously we observed that SS Pon3 KO rats on eight weeks high salt diet demonstrated significantly increased phenotypic renal injury and mortality. In the current study, we noted that SS Pon3 KO had significantly decreased (p<0.05) glomerular filtration rate compared to SS wild type. Blood pressure (radiotelemetry) as well as plasma angiotensin and aldosterone (LC-MS/MS) were not different between the two groups after high salt diet. We used targeted lipidomic profiling to determine eicosanoid content in renal cortex from SS Pon3 KO and SS wild type rats at the end of eight weeks of high salt diet. We found that hydroxyl fatty acids 5-HEPE and 5-HETE (5-lipoxygenase dependent arachidonic acid metabolites) were significantly (p<0.05) elevated in the renal cortex of SS Pon3 KO compared to SS wild type rats. In addition to being mediators of inflammation, these metabolites are associated with renal cell injury and death. Furthermore, prostaglandin 6-keto-PGF 1α , which has known links to renal inflammation, was significantly (p<0.05) increased in renal cortex of SS- Pon3 KO compared to SS wild type rats. Conclusion: These findings suggest that targeted deletion of Pon3 increases pro-inflammatory eicosanoids (5-HETE and 5-HEPE) and prostaglandins (6-keto-PGF 1α ), as well as increases renal damage independent of blood pressure.


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Teri M Kozik ◽  
Mouchumi Bhattacharyya ◽  
Teresa T Nguyen ◽  
Therese F Connolly ◽  
Walther Chien ◽  
...  

Introduction: Energy drinks are presumed to enhance energy, physical endurance, mood, and boost metabolism. Serious health risks have been reported with energy drink consumption such as myocardial infarction, cardiac arrest, stroke, seizures, and arrhythmias. More than 20,000 emergency department visits related to energy drink consumption were reported in 2011. Little is known about the possible pathophysiological mechanisms and adverse events associated with energy drinks. Unlike the tobacco and alcohol industry, there are limited restrictions regulating the purchasing and marketing of these drinks. Purpose: To determine if consumption of energy drinks alter; vital signs (blood pressure, temperature), electrolytes (magnesium, potassium, calcium), activated bleeding time (ACT), or cardiac responses measured with a 12-lead electrocardiographic (ECG) Holter. Method: Subjects consumed two-16 ounce cans of an energy drink within one hour and remained in the lab where data was collected at base line (BL) and then during four hours post consumption (PC). Vital signs were taken every 30 minutes; blood samples were collected at BL, one, two and four hours PC and ECG data was collected throughout the entire study period. Paired students t-test and a corresponding non-parametric test (Wilcoxon signed rank) were used for analysis of the data. Results: Fourteen healthy young subjects were recruited (mean age 28.6 years). Systolic blood pressure (BL=132, ±7.83; PC= 151, ±11.21; p=.001); QTc interval (BL=423, ±22.74; PC=503, ±24.56; p<.001); magnesium level (BL 2.04, ± 0.09; PC=2.13, ±0.15; p=.05); and calcium level (BL=9.31, ±.28; PC=9.52, ±.22; p=.018) significantly increased from BL. While potassium and ACT fluctuated (increase and decrease) no significant changes were observed. Eight of the fourteen subjects (57%) developed a QTc >500 milliseconds PC. Conclusions: In our sample, consumption of energy drinks increased systolic blood pressure, serum magnesium and calcium, and resulted in repolarization abnormalities. Because these physiological responses can lead to arrhythmias and other abnormal cardiac responses, further study in a larger sample is needed to determine the effects and possible consequences of energy drink consumption.


2004 ◽  
Vol 18 (3) ◽  
pp. 290-298 ◽  
Author(s):  
Thu H. Le ◽  
Michael I. Oliverio ◽  
Hyung-Suk Kim ◽  
Harmony Salzler ◽  
Rajesh C. Dash ◽  
...  

To understand the physiological role of angiotensin type 1 (AT1) receptors in the proximal tubule of the kidney, we generated a transgenic mouse line in which the major murine AT1 receptor isoform, AT1A, was expressed under the control of the P1 portion of the γ-glutamyl transpeptidase (γGT) promoter. In transgenic mice, this promoter has been shown to confer cell-specific expression in epithelial cells of the renal proximal tubule. To avoid random integration of multiple copies of the transgene, we used gene targeting to produce mice with a single-copy transgene insertion at the hypoxanthine phosphoribosyl transferase ( Hprt) locus on the X chromosome. The physiological effects of the γGT-AT1A transgene were examined on a wild-type background and in mice with targeted disruption of one or both of the murine AT1 receptor genes ( Agtr1a and Agtr1b). On all three backgrounds, γGT-AT1A transgenic mice were healthy and viable. On the wild-type background, the presence of the transgene did not affect development, blood pressure, or kidney structure. Despite relatively low levels of expression in the proximal tubule, the transgene blunted the increase in renin expression typically seen in AT1-deficient mice and partially rescued the kidney phenotype associated with Agtr1a−/− Agtr1b−/− mice, significantly reducing cortical cyst formation by more than threefold. However, these low levels of cell-specific expression of AT1 receptors in the renal proximal tubule did not increase the low blood pressures or abolish sodium sensitivity, which are characteristic of AT1 receptor-deficient mice. Although our studies do not clearly identify a role for AT1 receptors in the proximal tubules of the kidney in blood pressure homeostasis, they support a major role for these receptors in modulating renin expression and in maintaining structural integrity of the renal cortex.


2016 ◽  
Vol 310 (7) ◽  
pp. H861-H872 ◽  
Author(s):  
Yujia Wang ◽  
Zenghui Wu ◽  
Eric Thorin ◽  
Johanne Tremblay ◽  
Julie L. Lavoie ◽  
...  

EPH kinases and their ligands, ephrins (EFNs), have vital and diverse biological functions, although their function in blood pressure (BP) control has not been studied in detail. In the present study, we report that Efnb3 gene knockout (KO) led to increased BP in female but not male mice. Vascular smooth muscle cells (VSMCs) were target cells for EFNB3 function in BP regulation. The deletion of EFNB3 augmented contractility of VSMCs from female but not male KO mice, compared with their wild-type (WT) counterparts. Estrogen augmented VSMC contractility while testosterone reduced it in the absence of EFNB3, although these sex hormones had no effect on the contractility of VSMCs from WT mice. The effect of estrogen on KO VSMC contractility was via a nongenomic pathway involving GPER, while that of testosterone was likely via a genomic pathway, according to VSMC contractility assays and GPER knockdown assays. The sex hormone-dependent contraction phenotypes in KO VSMCs were reflected in BP in vivo. Ovariectomy rendered female KO mice normotensive. At the molecular level, EFNB3 KO in VSMCs resulted in reduced myosin light chain kinase phosphorylation, an event enhancing sensitivity to Ca2+ flux in VSMCs. Our investigation has revealed previously unknown EFNB3 functions in BP regulation and show that EFNB3 might be a hypertension risk gene in certain individuals.


Author(s):  
Xiao Chun Li ◽  
Ana Paula Oliveira Leite ◽  
Xiaowen Zheng ◽  
Chunling Zhao ◽  
Xu Chen ◽  
...  

The present study used a novel mouse model with proximal tubule-specific knockout of AT 1a receptors in the kidney, PT- Agtr1a −/− , to test the hypothesis that intratubular Ang II (angiotensin II) and AT 1a receptors in the proximal tubules are required for maintaining normal blood pressure and the development of Ang II–induced hypertension. Twenty-six groups (n=6–15 per group) of adult male wild-type, global Agtr1a −/− , and PT- Agtr1a −/− mice were infused with Ang II (1.5 mg/kg per day, IP), or overexpressed an intracellular Ang II fusion protein in the proximal tubules for 2 weeks. Basal telemetry blood pressure were ≈15±3 mm Hg lower in PT- Agtr1a −/− than wild-type mice and ≈13±3 mm Hg higher than Agtr1a −/− mice ( P <0.01). Basal glomerular filtration was ≈23.9% higher ( P <0.01), whereas fractional proximal tubule Na + reabsorption was lower in PT- Agtr1a −/− mice ( P <0.01). Deletion of AT 1a receptors in the proximal tubules augmented the pressure-natriuresis response ( P <0.01) and natriuretic responses to salt loading or Ang III infusion ( P <0.01). Ang II induced hypertension in wild-type, PT- Agtr1a −/− and PT- Nhe3 −/− mice, but the pressor response was ≈16±2 mm Hg lower in PT- Agtr1a −/− and PT- Nhe3 −/− mice ( P <0.01). Deletion of AT 1a receptors or NHE3 (Na + /H + exchanger 3) in the proximal tubules attenuated ≈50% of Ang II–induced hypertension in wild-type mice ( P <0.01), but blocked intracellular Ang II fusion protein-induced hypertension in PT- Agtr1a −/− mice ( P <0.01). Taken together, the results of the present study provide new insights into the critical role of intratubular Ang II/AT 1 (AT 1a )/NHE3 pathways in the proximal tubules in normal blood pressure control and the development of Ang II–induced hypertension.


2007 ◽  
Vol 293 (2) ◽  
pp. F586-F593 ◽  
Author(s):  
Xiao C. Li ◽  
L. Gabriel Navar ◽  
Yuan Shao ◽  
Jia L. Zhuo

We and others have previously shown that high levels of ANG II are accumulated in the rat kidney via a type 1 (AT1) receptor-mediated mechanism, but it is not known which AT1 receptor is involved in this process in rodents. We tested the hypothesis that AT1a receptor-deficient mice (Agtr1a−/−) are unable to accumulate ANG II intracellularly in the kidney because of the absence of AT1a receptor-mediated endocytosis. Adult male wild-type (Agtr1a+/+), heterozygous (Agtr1a+/−), and Agtr1a−/− were treated with vehicle, ANG II (40 ng/min ip via osmotic minipump), or ANG II plus the AT1 antagonist losartan (10 mg·kg−1·day−1 po) for 2 wk. In wild-type mice, ANG II induced hypertension (168 ± 4 vs. 113 ± 3 mmHg, P < 0.001), increased kidney-to-body weight ratio ( P < 0.01), caused pressure natriuresis ( P < 0.05), and elevated plasma and whole kidney ANG II levels ( P < 0.001). Concurrent administration of ANG II with losartan attenuated these responses to ANG II. In contrast, Agtr1a−/− mice had lower basal systolic pressures ( P < 0.001), smaller kidneys with much fewer AT1b receptors ( P < 0.001), higher basal 24-h urinary sodium excretion ( P < 0.01), as well as basal plasma and whole kidney ANG II levels ( P < 0.01). However, intracellular ANG II levels in the kidney were lower in Agtr1a−/− mice. In Agtr1a−/− mice, ANG II slightly increased systolic pressure ( P < 0.05) but had no effect on the kidney weight, urinary sodium excretion, and whole kidney ANG II levels. Losartan restored systolic pressure to basal levels and decreased whole kidney ANG II levels by ∼20% ( P < 0.05). These results demonstrate a predominant role of AT1a receptors in blood pressure regulation and in the renal responses to long-term ANG II administration, that AT1b receptors may play a limited role in blood pressure control and mediating intrarenal ANG II accumulation in the absence of AT1a receptors.


Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Antoine Caillon ◽  
Muhammad Oneeb Rehman Mian ◽  
Tlili Barhoumi ◽  
Pierre Paradis ◽  
Ernesto L. Schiffrin

Objective: Both innate antigen presenting cells and the adaptive immune system have been shown to play a role in the development of hypertension. Nevertheless, the T cell subset involved in the pathophysiology of hypertension remains unclear. There is a small subset of “innate-like” T cells expressing gamma/delta T cell receptor (TCR) rather than the alpha/beta TCR that could play a role in bridging between the innate and adaptive immune systems. However, it is unknown whether gamma/delta T cells contribute to development of hypertension. Method/Results: Thirteen to 15 week-old male C57BL/6 wild-type and Tcrd-/- mice, which are devoid of gamma/delta T cells, were infused or not with angiotensin (Ang) II (490 ng/kg/min, SC) for 7 or 14 days (n=4-9). Telemetric blood pressure, mesenteric artery endothelial function and vascular remodeling by pressurized myography and spleen T cell profile by flow cytometry were evaluated. Fourteen days of Ang II increased systolic blood pressure (167±4 vs 125±2 mmHg, P≤0.01) in wild-type compared to control mice. The frequency of gamma/delta T cells (6±1% vs 3±1%, P≤0.05) and activated (CD69+) gamma/delta T cells (11±1% vs 7±1%) was increased after 7 days of Ang II, and 7 days later were respectively unchanged or further increased (24±2% vs 10±1%) in wild-type compared to control mice. Ang II decreased mesenteric artery relaxation responses to acetylcholine (51±5% vs 88±3%, P≤0.01) and increased media/lumen (5±1 vs 3±0%, P≤0.01) in wild-type mice compare to controls. No gamma/delta T cells were detected in Tcrd-/- treated or not with Ang II. All the above Ang II effects were abrogated in Tcrd-/- mice. Conclusion: These data suggest that gamma/delta T cells mediate Ang II-induced blood pressure rise and vascular injury. Gamma/delta T cells could be key immune cells bridging innate and adaptive immune responses during the development of hypertension.


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