Aldosterone Receptor Antagonism Normalizes Vascular Function in 11β-Hydroxysteroid Dehydrogenase Deficient Hypertension

Hypertension ◽  
2000 ◽  
Vol 36 (suppl_1) ◽  
pp. 691-691
Author(s):  
Thomas Quaschning ◽  
Frank T Ruschitzka ◽  
Carolyn Mb Lunt ◽  
Bernhard Niggli ◽  
Sidney Shaw ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Protein Content ◽  
Vascular Function ◽  
Hydroxysteroid Dehydrogenase ◽  
Receptor Antagonism ◽  
Tissue Levels ◽  
Protein Levels ◽  
Aldosterone Receptor ◽  
Endothelium Dependent Relaxation ◽  
Enos Protein

76 Background: The enzyme 11β-hydroxysteroid dehydrogenase (11β-HSD2) provides mineralocorticoid receptor specificity for aldosterone by metabolising glucocorticoids to their receptor inactive 11-dehydro derivatives. The present study investigated the effect of the aldosterone receptor antagonist spironolactone on endothelial function in liquorrhice induced hypertension. Methods: Glycyrrhizic acid (GA), a recognised inhibitor of 11β-HSD2 was supplemented to the drinking water (3g/L) of Wistar Kyoto rats over a period of 21 days. From day 8 to 21 spirolonoactone (5.8±0.6 mg/kg/d) or placebo was added to chow (n=7/group). Endothelium-dependent and -independent vascular function was assessed as relaxation of preconstricted aortic rings to acetylcholine (10 -10 -10 -5 mol/L) or sodium nitroprusside (10 -10 -10 -5 mol/L). Furthermore aortic eNOS protein content, nitrate tissue levels, endothelin-1 (ET-1) protein levels were determined. Results: GA application increased SBP to 185±9 mmHg vs 142±8 mmHg in control animals, p<0.01). In the GA group endothelium-dependent relaxation was impaired as compared to controls (73±6% vs 99±5% of norepinephrine 3x10 -7 mol/L), whereas endothelium independent relaxation remained unchanged. In the aorta of 11β-HSD2 deficient rats, eNOS protein content and nitrate tissue levels (1114±128 vs 518±77μg/g protein, p<0.05) decreased. In contrast, aortic endothelin-1 (ET-1) protein levels were enhanced by GA. (308±38 vs 497±47 pg/mg tissue, p<0.05). Treatment with spironolactone normalized blood pressure in animals on GA (142±9 mmHg vs 189±8 mmHg in the placebo group; p<0.01) and restored endothelium-dependent relaxation (96±3%, p<0.01 vs placebo). Spironolactone furthermore blunted the decrease in vascular eNOS protein content and nitrate tissue levels as well as the elevation of ET-1 protein levels. Conclusion: In 11β-HSD2-deficient hypertension, aldosterone receptor antagonism normalizes blood pressure, prevents up-regulation of vascular ET-1 and restores NO-mediated endothelial dysfunction and therefore may advance as a novel therapeutic approach.

scholarly journals Activation of angiotensin type 2 receptor attenuates testosterone-induced hypertension and uterine vascular resistance in pregnant rats

2021 ◽  
Author(s):  
Jay S Mishra ◽  
Sathish Kumar
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Vascular Function ◽  
Uterine Artery ◽  
Artery Blood Flow ◽  
Protein Levels ◽  
Angiotensin Type 2 Receptor ◽  
Enos Protein ◽  
Angiotensin Type

Abstract Preeclampsia is a pregnancy-related hypertensive disorder with unclear mechanisms. While hypersensitivity to angiotensin II via vasoconstrictive angiotensin type-1 receptor (AT1R) is observed in preeclampsia, the importance of vasodilatory angiotensin type-2 receptor (AT2R) in the control of vascular dysfunction is less clear. We assessed whether AT1R, AT2R and eNOS expression is altered in placental vessels of preeclamptic women and tested if ex vivo incubation with AT2R agonist Compound 21 (C21; 1 μM) could restore AT1R, AT2R and eNOS balance. Further, using a rat model of gestational hypertension induced by elevated testosterone, we examined whether C21 (1 μg·kg−1·day−1, oral) could preserve AT1R and AT2R balance and improve blood pressure, uterine artery blood flow, and vascular function. Western blots revealed that AT1R protein level was higher while AT2R and eNOS protein were reduced in preeclamptic placental vessels, and AT2R agonist C21 decreased AT1R and increased AT2R and eNOS protein levels in preeclamptic vessels. In testosterone-dams, blood pressure was higher, and uterine artery blood flow was reduced, and C21 treatment reversed these levels similar to those in controls dams. C21 attenuated the exaggerated Ang II contraction and improved endothelium-dependent vasorelaxation in uterine arteries of testosterone-dams. These C21-mediated vascular effects were associated with decreased AT1R and increased AT2R and eNOS protein levels. C21 also increased serum nitrate/nitrite and bradykinin production in testosterone-dams and attenuated the feto-placental growth restriction. Thus, AT1R upregulation and AT2R downregulation is observed in preeclampsia and testosterone-model, and increasing AT2R activity could help restore AT1R and AT2R balance and improve gestational vascular function.

Abstract 057: Nox5 Induces Vascular Dysfunction and Arterial Remodelling Independently of Blood Pressure Elevation in Ang II-infused Nox5-expressing Mice

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Augusto C Montezano ◽  
Adam P Harvey ◽  
Francisco J Rios ◽  
Maria Dulak-Lis ◽  
Wendy Beatie ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Vascular Function ◽  
Kinase Inhibitor ◽  
Vascular Dysfunction ◽  
Rho Kinase ◽  
Lumen Diameter ◽  
Ang Ii ◽  
Cross Sectional ◽  
Blood Pressure Elevation ◽  
Endothelium Dependent Relaxation

Nox5 is a unique Ca 2+ -sensitive Nox isoform that is expressed in human vascular smooth muscle cells (VSMC). Although Nox5 has been implicated in diabetic nephropathy, its role in vascular function and development of hypertension remain unclear. Nox5 is not expressed in rodents, and accordingly we generated humanised Nox5 mice with Nox5 expressed in a VSMC-specific manner (Nox5SM22). Control (wild-type) and Nox5SM22 mice were infused with Ang II (600 ng/Kg/day). Blood pressure (BP) was assessed by tail-cuff. Vascular function and structure of resistance arteries were measured by myography. Ang II increased BP in WT (182.5±10 mmHg) and Nox5SM22 mice (173.1±5 mmHg) with no significant differences. Arteries from Nox5SM22 mice exhibited reduced endothelium-dependent relaxation versus WT controls (%ACh relaxation: 55.1±4 vs ctl: 81.6±7%). Fasudil (Rho kinase inhibitor)-induced relaxation was reduced in Nox5SM22 mice versus controls (%Fas: 111.3±11 vs ctl: 166.6±8%) (p<0.05). Ang II increased the maximal contraction to U46619 (thromboxane A2 mimetic) in WT (115.8±2 vs untreated: 101.4±2%) and Nox5SM22 (121.3±3 vs untreated: 99.1±2) (p<0.05) and induced endothelial dysfunction in all groups. Fasudil-induced relaxation was impaired by Ang II in WT (102.7±6 vs untreated: 166.6±8%, p<0.05) but not further impaired in Nox5SM22 mice (114.9±6 vs untreated: 111.3±11%). Ang II increased cross-sectional area (CSA) and lumen diameter; while in Nox5SM22 mice, Ang II increased wall thickness, wall-to-lumen ratio, CSA and decreased lumen diameter, with associated increased vascular stiffness. Our findings indicate that in mice expressing human Nox5 in VSMCs, endothelium-dependent relaxation is impaired, fasudil-mediated vasodilation is attenuated and vessels undergo exaggerated hypertrophic inward remodelling with increased stiffness; processes that occur independently of BP elevation. These data suggest an important role for Nox5 in Ang II-induced vascular dysfunction and remodeling, but not in the development of hypertension. Moreover, we identify Rho kinase as a putative target for Nox5-induced vascular injury. We provide novel insights into Nox5 vascular biology and demonstrate that vascular Nox5 actions are dissociated from BP effects.

scholarly journals Aldosterone Receptor Antagonism Normalizes Vascular Function in Liquorice-Induced Hypertension

Hypertension ◽  
2001 ◽  
Vol 37 (2) ◽  
pp. 801-805 ◽  
Author(s):  
Thomas Quaschning ◽  
Frank Ruschitzka ◽  
Sidney Shaw ◽  
Thomas F. Lüscher
Keyword(s):  
Vascular Function ◽  
Receptor Antagonism ◽  
Aldosterone Receptor ◽  
Induced Hypertension

Abstract 345: Effects Of Endothelial-targeted Overexpression Of Nox4 On Vascular Tone And Blood Pressure In Mice

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Robin Ray ◽  
Min Zhang ◽  
Alison C Brewer ◽  
Ajay M Shah
Keyword(s):  
Blood Pressure ◽  
Transgenic Mice ◽  
Fold Increase ◽  
Wild Type ◽  
Protein Levels ◽  
Promoter Construct ◽  
Activation Mechanisms ◽  
Endothelium Dependent Relaxation

NADPH oxidases (Noxs) are major sources of reactive oxygen species (ROS) that are involved in the pathophysiology of several cardiovascular disorders. Of the 5 Nox isoforms identified to date, Nox2 and Nox4 are the main isoforms expressed in the endothelium. Whereas Nox2 has been implicated in the genesis of endothelial dysfunction, the role of Nox4 remains unclear. Interestingly, the activation mechanisms of Nox2 and Nox4 appear to be distinct. To specifically examine the function of endothelial Nox4 in vivo , we generated transgenic mice with endothelial-targeted overexpression of Nox4 using a Tie2 promoter construct. Nox4 transgenic mice (TG) backcrossed onto a C57BL/6J background had increased Nox4 mRNA in endothelial-rich tissues and in isolated coronary microvascular endothelial cells (CMEC) compared to wild-type littermates (WT) (2-fold increase in CMEC; p<0.001). Aortic Nox4 protein levels were 3-fold higher in TG compared to WT. CMEC isolated from TG mice had increased NADPH-dependent superoxide production compared to WT (237.6 ± 2.7 vs. 186.5 ± 7.1 integrated RLU; n = 3, p<0.01) as well as increased H 2 O 2 production (7.60 ± 0.70 vs. 3.22 ± 0.42 μM H 2 O 2 /105 cells; n=3, p<0.01). No changes were detected in mRNA expression of SOD1, SOD2, SOD3, catalase or eNOS in aorta of TG compared to WT mice. Isolated aortic rings from TG mice exhibited enhanced endothelial-dependent vasorelaxation to cumulative addition of acetylcholine compared to WT (−log EC 50 7.76 ± 0.07 vs. 7.20 ± 0.05; n =12, p<0.001), a difference that was abolished by catalase (1500 units/ml). There was no difference in endothelial-independent responses to sodium nitroprusside (−log EC 50 8.57 ± 0.11 vs. 8.54 ± 0.09; n = 12, p = NS). In vivo blood pressure measured both by tail-cuff plethysmography and ambulatory telemetry was significantly lower in TG compared to WT (systolic 117.4 ± 1.9 vs. 125.5 ± 2.1 mmHg and diastolic 90.1 ± 2.0 vs. 98.1 ± 2.1 mmHg by telemetry; n =5, p<0.05). These results indicate that modest endothelium-targeted overexpression of Nox4 in vivo enhances endothelium-dependent relaxation and reduces blood pressure, probably through increased generation of H 2 O 2 . These in vivo effects are quite distinct from those that have been found with Nox2 overexpression.

Inhibition of 11β-Hydroxysteroid Dehydrogenase in Pregnant Rats and the Programming of Blood Pressure in the Offspring

Hypertension ◽  
1996 ◽  
Vol 27 (6) ◽  
pp. 1200-1204 ◽  
Author(s):  
Robert S. Lindsay ◽  
R. Mark Lindsay ◽  
Christopher R.W. Edwards ◽  
Jonathan R. Seckl
Keyword(s):  
Blood Pressure ◽  
Hydroxysteroid Dehydrogenase ◽  
Pregnant Rats

Cardiovascular Responses to Muscle Stretching: A Systematic Review and Meta-analysis

2021 ◽  
Author(s):  
Ewan Thomas ◽  
Marianna Bellafiore ◽  
Ambra Gentile ◽  
Antonio Paoli ◽  
Antonio Palma ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiovascular System ◽  
Vascular Function ◽  
Meta Analysis ◽  
Random Effect ◽  
Cardiovascular Responses ◽  
Qualitative Description ◽  
Cross Sectional ◽  
Quantitative Synthesis

AbstractThe aim of this study will be to review the current body of literature to understand the effects of stretching on the responses of the cardiovascular system. A literature search was performed using the following databases: Scopus, NLM Pubmed and ScienceDirect. Studies regarding the effects of stretching on responses of the cardiovascular system were investigated. Outcomes regarded heart rate(HR), blood pressure, pulse wave velocity (PWV of which baPWV for brachial-ankle and cfPWV for carotid-femoral waveforms), heart rate variability and endothelial vascular function. Subsequently, the effects of each outcome were quantitatively synthetized using meta-analytic synthesis with random-effect models. A total of 16 studies were considered eligible and included in the quantitative synthesis. Groups were also stratified according to cross-sectional or longitudinal stretching interventions. Quality assessment through the NHLBI tools observed a “fair-to-good” quality of the studies. The meta-analytic synthesis showed a significant effect of d=0.38 concerning HR, d=2.04 regarding baPWV and d=0.46 for cfPWV. Stretching significantly reduces arterial stiffness and HR. The qualitative description of the studies was also supported by the meta-analytic synthesis. No adverse effects were reported, after stretching, in patients affected by cardiovascular disease on blood pressure. There is a lack of studies regarding vascular adaptations to stretching.

scholarly journals Oxidative Stress Mediates the Fetal Programming of Hypertension by Glucocorticoids

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 531
Author(s):  
Jeremy Lamothe ◽  
Sandhya Khurana ◽  
Sujeenthar Tharmalingam ◽  
Chad Williamson ◽  
Collin J. Byrne ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Superoxide Dismutase ◽  
Fetal Programming ◽  
Cardiovascular Health ◽  
Phenylalanine Hydroxylase ◽  
Epigallocatechin Gallate ◽  
Female Offspring ◽  
Glutathione Peroxidase 1 ◽  
Protein Levels

The field of cardiovascular fetal programming has emphasized the importance of the uterine environment on postnatal cardiovascular health. Studies have linked increased fetal glucocorticoid exposure, either from exogenous sources (such as dexamethasone (Dex) injections), or from maternal stress, to the development of adult cardiovascular pathologies. Although the mechanisms are not fully understood, alterations in gene expression driven by altered oxidative stress and epigenetic pathways are implicated in glucocorticoid-mediated cardiovascular programming. Antioxidants, such as the naturally occurring polyphenol epigallocatechin gallate (EGCG), or the superoxide dismutase (SOD) 4-hydroxy-TEMPO (TEMPOL), have shown promise in the prevention of cardiovascular dysfunction and programming. This study investigated maternal antioxidant administration with EGCG or TEMPOL and their ability to attenuate the fetal programming of hypertension via Dex injections in WKY rats. Results from this study indicate that, while Dex-programming increased blood pressure in male and female adult offspring, administration of EGCG or TEMPOL via maternal drinking water attenuated Dex-programmed increases in blood pressure, as well as changes in adrenal mRNA and protein levels of catecholamine biosynthetic enzymes phenylalanine hydroxylase (PAH), tyrosine hydroxylase (TH), dopamine beta hydroxylase (DBH), and phenylethanolamine N-methyltransferase (PNMT), in a sex-specific manner. Furthermore, programmed male offspring displayed reduced antioxidant glutathione peroxidase 1 (Gpx1) expression, increased superoxide dismutase 1 (SOD1) and catalase (CAT) expression, and increased pro-oxidant NADPH oxidase activator 1 (Noxa1) expression in the adrenal glands. In addition, prenatal Dex exposure alters expression of epigenetic regulators histone deacetylase (HDAC) 1, 5, 6, 7, 11, in male and HDAC7 in female offspring. These results suggest that glucocorticoids may mediate the fetal programming of hypertension via alteration of epigenetic machinery and oxidative stress pathways.

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