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Sim JSN, Farquharson C, Struthers AD. Tonic levels of angiotensin II reduce tonic levels of vascular nitric oxide even in salt-replete man. J Renin Angiotensin Aldosterone Syst 2016; 5:84-8. [PMID: 15295720 DOI: 10.3317/jraas.2004.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Introduction Losartan improves stimulated endothelial function in patients with cardiovascular disease, but there are no data to establish whether losartan has this effect in normal man. Furthermore, whether losartan improves basal nitric oxide (NO) activity is controversial. We therefore examined whether treatment with losartan improved basal NO activity in normal, salt-replete man. If so, this would imply that tonic levels of angiotensin II (Ang II) reduce tonic basal levels of NO, even in salt-replete normal man. Methods We performed a randomised, placebo-controlled, double-blind crossover study in 24 healthy volunteers, comparing losartan 50 mg daily for one month versus placebo. Brachial artery endothelial function was assessed by bilateral venous occlusion plethysmography, measuring the response to intra-arterial infusions of the endothelial-dependent and endothelial-independent vasodilators, acetylcholine and sodium nitroprusside respectively and the endothelial-dependent vasoconstrictor NG-monomethyl-L-arginine. Results were analysed by multiple analysis of variance and statistical significance was taken as a p value of ≤ 0.05. Results Losartan significantly increased the vasoconstriction in response to N G-monomethyl-L-arginine (-37 2% vs. -32+2%, losartan vs. placebo; p=0.05). Losartan improved the vasodilatation response to acetylcholine; however, this result did not reach significance (214+2 0% vs. 174+20%, losartan vs. placebo; p=0.15). Losartan did not affect the response to nitroprusside (172+15% vs. 176+16%, losartan vs. placebo; p=0.84). There was no significant difference in blood pressure between the two study days. Conclusions Losartan improves basal NO bioactivity in healthy salt-replete volunteers. Even in salt-replete man, basal Ang II levels exert a tonic effect, which reduces basal NO.
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Affiliation(s)
- Justein S N Sim
- Division of Medicine & Therapeutics, Ninewells Hospital & Medical School, Dundee, UK
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Kuzubova NA, Chukhlovin AB, Morozova EB, Totolian AA, Titova ON. Common intronic D variant of ACE gene is associated with endothelial dysfunction in COPD. Respir Med 2013; 107:1217-21. [PMID: 23702088 DOI: 10.1016/j.rmed.2012.12.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 11/01/2012] [Accepted: 12/12/2012] [Indexed: 10/26/2022]
Abstract
BACKGROUND Pathogenesis of chronic obstructive lung disease (COPD) includes primary inflammatory events, multiple vascular reactions, remodeling of bronchial and vascular walls. OBJECTIVE The aim of present single-center study was to assess relations between angiotensin-converting enzyme (ACE) gene and prevalence of clinical symptoms characteristic to COPD. METHODS The study involved sixty-three male patients with COPD (44-86 years old, a mean of 60.4 years). COPD diagnostics was performed according to common criteria, including evaluation of systolic pressure in pulmonary artery (SPPA) and endothelial disfunction (ED). Genotyping of ACE I/D was performed by means of gene-specific PCR. RESULTS 1. Allele distribution of studied gene alleles among COPD patients did not differ from control age-matched group. 2. Detectable endothelial dysfunction in COPD patients was shown to correlate with high-producer D allele of ACE gene, at an odds ratio of 6.632 (CI = 1.67-26.31; chi2 = 8.39, p = 0.004). Moreover, detectable ED correlated with numbers of COPD exacerbations per year. CONCLUSIONS These findings suggest possible association of the functional ACE D allele with altered vascular responses that may modulate development of distinct COPD symptoms. The results are obtained in a limited clinical cohort, and deserve repeated trials in other groups of COPD patients.
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Affiliation(s)
- Natalia A Kuzubova
- Research Institute of Pulmonology, St. Petersburg State I. Pavlov Medical University, 197089 St. Petersburg, Russia Federation
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Pereira TV, Nunes ACF, Rudnicki M, Yamada Y, Pereira AC, Krieger JE. Meta-analysis of the association of 4 angiotensinogen polymorphisms with essential hypertension: a role beyond M235T? Hypertension 2008; 51:778-83. [PMID: 18227406 DOI: 10.1161/hypertensionaha.107.100370] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Angiotensinogen (AGT) gene polymorphisms have been linked to increased risk of hypertension, but the data remain controversial. In this study we review the most commonly investigated polymorphisms at the AGT locus (other than M235T) and provide summary estimates regarding their association with essential hypertension, while addressing heterogeneity, as well as publication biases. Data on 26 818 subjects from 46 studies for the 4 most-studied AGT variants (T174M in exon 2 and 3 promoter variants: A-6G, A-20C, and G-217A) were meta-analyzed. Statistically significant associations with hypertension were identified for the T174M (odds ratio [OR]: 1.19; 95% CI: 1.07 to 1.33; P=0.002) and G-217A (OR: 1.37; 95% CI: 1.17 to 1.59; P=0.00006) polymorphisms. A dual but consistent effect was observed for the -20C allele, which was associated with a decreased risk of hypertension in populations of mixed and European ancestries (OR: 0.64; 95% CI: 0.44 to 0.92; P=0.02 and OR: 0.77; 95% CI: 0.65 to 0.91; P=0.003, respectively), but with a 24% increase in the odds of hypertension in Asian subjects (OR: 1.24; 95% CI: 1.04 to 1.48; P=0.02). No association of the A-6G variant with hypertension was detected. Current studies support the notion that single variants at the AGT might modulate the risk of hypertension but indicate caution in interpreting these results because of the putative presence of publication bias and gene-environment interactions.
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Affiliation(s)
- Tiago Veiga Pereira
- Heart Institute (InCor), Faculty of Pharmaceutical Sciences, University of Sao Paulo Medical School, São Paulo, Brazil
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Kiliszek M, Burzyńska B, Styczyński G, Maciag M, Rabczenko D, Opolski G. A1166C polymorphism of the angiotensin AT1 receptor (AT1R) gene alters endothelial response to statin treatment. Clin Chem Lab Med 2007; 45:839-42. [PMID: 17617024 DOI: 10.1515/cclm.2007.151] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The function of vascular endothelium is influenced by several factors: low-density lipoprotein (LDL) cholesterol, oxidative stress and the reninangiotensin system. METHODS We tested the hypothesis that polymorphisms A1166C of the angiotensin AT1 receptor (AT1R) gene, C242T and A640G of the pphox22 gene (p22 phox is an essential component of NADH/NADPH oxidases) and G894T of the endothelial nitric oxide (NO) synthase (eNOS) gene influence endothelial function and its reaction to statin treatment. In 44 patients with coronary artery disease or hypercholesterolemia (not on lipid-lowering treatment), lipid profile and endothelial function (brachial artery flow-mediated dilation, FMD) were measured at baseline and after treatment with statins for 8-12 weeks. All subjects were genotyped for the above-mentioned polymorphisms. RESULTS None of the polymorphisms significantly predicted baseline FMD. Patients with the C allele of A1166C showed smaller changes in FMD in comparison with patients with the AA genotype (-0.044+/-0.439% vs. 0.386+/-0.599%; p=0.016). None of the other polymorphisms significantly influenced changes in FMD. CONCLUSIONS The C allele of AT1R A1166C is associated with significantly lower endothelial response to statin treatment.
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Affiliation(s)
- Marek Kiliszek
- Department of Cardiology, Medical University of Warsaw, Warsaw, Poland.
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Vasan RS, Larson MG, Aragam J, Wang TJ, Mitchell GF, Kathiresan S, Newton-Cheh C, Vita JA, Keyes MJ, O'Donnell CJ, Levy D, Benjamin EJ. Genome-wide association of echocardiographic dimensions, brachial artery endothelial function and treadmill exercise responses in the Framingham Heart Study. BMC MEDICAL GENETICS 2007; 8 Suppl 1:S2. [PMID: 17903301 PMCID: PMC1995617 DOI: 10.1186/1471-2350-8-s1-s2] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND Echocardiographic left ventricular (LV) measurements, exercise responses to standardized treadmill test (ETT) and brachial artery (BA) vascular function are heritable traits that are associated with cardiovascular disease risk. We conducted a genome-wide association study (GWAS) in the community-based Framingham Heart Study. METHODS We estimated multivariable-adjusted residuals for quantitative echocardiography, ETT and BA function traits. Echocardiography residuals were averaged across 4 examinations and included LV mass, diastolic and systolic dimensions, wall thickness, fractional shortening, left atrial and aortic root size. ETT measures (single exam) included systolic blood pressure and heart rate responses during exercise stage 2, and at 3 minutes post-exercise. BA measures (single exam) included vessel diameter, flow-mediated dilation (FMD), and baseline and hyperemic flow responses. Generalized estimating equations (GEE), family-based association tests (FBAT) and variance-components linkage were used to relate multivariable-adjusted trait residuals to 70,987 SNPs (Human 100K GeneChip, Affymetrix) restricted to autosomal SNPs with minor allele frequency > or =0.10, genotype call rate > or =0.80, and Hardy-Weinberg equilibrium p > or = 0.001. RESULTS We summarize results from 17 traits in up to 1238 related middle-aged to elderly men and women. Results of all association and linkage analyses are web-posted at http://ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?id=phs000007 webcite. We confirmed modest-to-strong heritabilities (estimates 0.30-0.52) for several Echo, ETT and BA function traits. Overall, p < 10(-5) in either GEE or FBAT models were observed for 21 SNPs (nine for echocardiography, eleven for ETT and one for BA function). The top SNPs associated were (GEE results): LV diastolic dimension, rs1379659 (SLIT2, p = 1.17*10(-7)); LV systolic dimension, rs10504543 (KCNB2, p = 5.18*10(-6)); LV mass, rs10498091 (p = 5.68*10(-6)); Left atrial size, rs1935881 (FAM5C, p = 6.56*10(-6)); exercise heart rate, rs6847149 (NOLA1, p = 2.74*10(-6)); exercise systolic blood pressure, rs2553268 (WRN, p = 6.3*10(-6)); BA baseline flow, rs3814219 (OBFC1, 9.48*10(-7)), and FMD, rs4148686 (CFTR, p = 1.13*10(-5)). Several SNPs are reasonable biological candidates, with some being related to multiple traits suggesting pleiotropy. The peak LOD score was for LV mass (4.38; chromosome 5); the 1.5 LOD support interval included NRG2. CONCLUSION In hypothesis-generating GWAS of echocardiography, ETT and BA vascular function in a moderate-sized community-based sample, we identified several SNPs that are candidates for replication attempts and we provide a web-based GWAS resource for the research community.
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Affiliation(s)
- Ramachandran S Vasan
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - Martin G Larson
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- Department of Mathematics and Statistics, Boston University, Boston, MA, USA
| | | | - Thomas J Wang
- Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Sekar Kathiresan
- Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Program in Medical and Population Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, MA, USA
| | - Christopher Newton-Cheh
- Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Program in Medical and Population Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, MA, USA
| | - Joseph A Vita
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - Michelle J Keyes
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- Department of Mathematics and Statistics, Boston University, Boston, MA, USA
| | - Christopher J O'Donnell
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Daniel Levy
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Emelia J Benjamin
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
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Méthot J, Hamelin BA, Arsenault M, Bogaty P, Plante S, Poirier P. The ACE-DD genotype is associated with endothelial dysfunction in postmenopausal women. Menopause 2007; 13:959-66. [PMID: 17003740 DOI: 10.1097/01.gme.0000243576.09065.93] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To evaluate the effects of the angiotensin-converting enzyme (ACE) insertion/deletion (I/D), the angiotensinogen M235T and the angiotensin II type 1 receptor A1166C polymorphisms, and hormone therapy used on endothelial function in postmenopausal women without manifestation of coronary artery disease. DESIGN Sixty-four postmenopausal women (42 hormone therapy users and 22 hormone therapy nonusers) without clinical manifestation of coronary artery disease were evaluated using external vascular ultrasonography to measure endothelium-dependent (hyperemic response, flow-mediated dilatation) and -independent (nitroglycerin) dilatation. Genotypes were determined by polymerase chain reaction amplification. RESULTS Women with the ACE-DD genotype displayed a lower flow-mediated dilatation compared to those with the ACE-II genotype (8.4% +/- 3.9% vs 12.6% +/- 5.4%, P = 0.04). Endothelial function was not associated with the angiotensinogen M235T and anglotensin II type 1 receptor A1166C polymorphisms. ACE polymorphism seems to modulate endothelial function among postmenopausal women without hormone therapy (8.2% +/- 5.1% vs 18.4% +/- 5.9% for the DD and the II genotype, respectively, P = 0.02). However, in hormone therapy users, flow-mediated dilatation was similar according to the ACE genotypes. CONCLUSIONS Our findings suggest that ACE-I/D polymorphism is related to endothelial dysfunction in postmenopausal women. Furthermore, a potential interaction between estrogen users and ACE polymorphism on endothelial function may be present.
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Affiliation(s)
- Julie Méthot
- Quebec Heart Institute/Laval Hospital, Laval University, Ste-Foy, Quebec, Canada
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Abstract
Molecular variants of individual components of the renin-angiotensin system (RAS) have been thought to contribute to an inherited predisposition towards essential hypertension. The angiotensin II type 1 receptor (AT-1) mediates the major pressor and trophic actions of angiotensin II (Ang II) and at least 50 different polymorphisms have been described in the AT-1 gene (AT(1)R gene); in particular, the C allele of the +1166A/C polymorphism has been associated with the severe form of essential hypertension, but the role of this polymorphism is still ambiguous in pathologies related to high Ang II levels, such as deterioration of renal function, arterial stiffness and hypertrophic cardiomyopathy. A relationship was suggested between AT 1R A1166C polymorphism and the humoral and renal haemodynamic responses to losartan, an AT-1 blocker, as well as with enhanced Ang II vascular reactivity or sensitivity. Polymorphism has also been described in angiotensin II type 2 receptor (AT-2) gene, AT-2 being the mediator for vasodilatation, natriuresis and apoptosis of smooth muscle cells; associations were found between some of these polymorphisms and both hypertension and left ventricular structure. Further evaluation in adequately powered studies is necessary for full assessment of the allelic markers in genes for RAS components, as well as to allow determination of a predisposition to hypertension or related diseases and selection of an appropriate antihypertensive drug for an individual.
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Affiliation(s)
- Bruno Baudin
- Service de Biochimie A, Hôpital Saint-Antoine, 184 rue du faubourg Saint-Antoine, 75571 Paris, Cedex 12, France.
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