Abstract:
BACKGROUND:Recent studies have shown that tamoxifen, which belongs to a group called selective estrogen receptor modulators (SERM), may exert protective effects against cardiovascular diseases and stroke in postmenopausal women. On the other hand, abnormalities in physical properties of the cell membranes may underlie the defects that are strongly linked to hypertension, stroke, and other cardiovascular diseases. The present study was performed to investigate the effects of tamoxifen on cell membrane fluidity (a reciprocal value of membrane microviscosity) in normotensive and hypertensive postmenopausal women. METHODS AND RESULTS:We used an electron paramagnetic resonance (EPR) and spin-labeling method. Tamoxifen significantly decreased the order parameter (S) for 5-nitroxide stearate (5-NS) and the peak height ratio (h(o)/h(-1)) for 16-NS obtained from EPR spectra of erythrocyte membranes in normotensive postmenopausal women (mean +/- SEM, order parameter value; control 0.719 +/- 0.002, n = 41; tamoxifen 1 x 10(-7) mol/L 0.704 +/- 0.002, n = 41, P < .0001; tamoxifen 1 x 10(-6) mol/L 0.696 +/- 0.002, n = 41, P < .0001; tamoxifen 1 x 10(-5) mol/L 0.692 +/- 0.002, n = 41, P < .0001). The finding indicated that tamoxifen increased the membrane fluidity and improved the membrane microviscosity of erythrocytes. The membrane action of tamoxifen was antagonized by the estrogen receptor antagonist ICI 182,780. The effect of tamoxifen was significantly potentiated by the nitric oxide (NO) donors, l-arginine and S-nitroso-N-acetylpenicillamine, and a cGMP analog 8-bromo-cGMP. In contrast, the change evoked by tamoxifen was counteracted by the NO synthase inhibitors N(G)-nitro-l-arginine-methyl-ester and asymmetric dimethyl-l-arginine. In hypertensive postmenopausal women, the membrane fluidity of erythrocytes was significantly lower than in normotensive postmenopausal women. The effect of tamoxifen on the membrane fluidity was more pronounced in hypertensive postmenopausal women than in normotensive postmenopausal women. CONCLUSIONS:These results showed that tamoxifen increased the membrane fluidity of erythrocytes and improved the rigidity of cell membranes in postmenopausal women, to some extent, through the NO- and cGMP-dependent mechanisms. Furthermore, the greater effect of tamoxifen in hypertensive postmenopausal women suggests that tamoxifen could have a beneficial effect in regulating the blood rheologic behavior and in the improvement of the microcirculation in hypertension.
journal_name
Am J Hypertensjournal_title
American journal of hypertensionauthors
Tsuda K,Nishio Idoi
10.1016/j.amjhyper.2005.02.009subject
Has Abstractpub_date
2005-08-01 00:00:00pages
1067-76issue
8eissn
0895-7061issn
1941-7225pii
S0895-7061(05)00098-1journal_volume
18pub_type
杂志文章abstract:BACKGROUND:The aim of this study was to clarify the response of endothelial connexins to hypertension and antihypertensive drugs. METHODS:Rats remained normotensive (group 1, N = 10) or were made hypertensive using N(omega)-nitro-L-arginine methyl ester (L-NAME) (groups 2 to 4, N = 10/group). Seven weeks later groups ...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/j.amjhyper.2005.08.020
更新日期:2006-02-01 00:00:00
abstract::Kidney stones affect hypertensive patients disproportionately compared to normotensive individuals. On the other hand, some prospective data suggest that a history of nephrolithiasis was associated with a greater tendency to develop hypertension. Newer epidemiologic data also link obesity and diabetes, features of the...
journal_title:American journal of hypertension
pub_type: 杂志文章,评审
doi:10.1038/ajh.2007.62
更新日期:2008-03-01 00:00:00
abstract:BACKGROUND:Although several characteristics of aortic function, which are largely determined by age, predict outcomes beyond brachial blood pressure (BP), the extent to which brachial BP control accounts for age-related variations in aortic function is uncertain. We aimed to determine the extent to which brachial BP co...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/hpv140
更新日期:2016-05-01 00:00:00
abstract::Smooth muscle cells from spontaneously hypertensive rats (SHR) proliferate in culture faster than those isolated from sex- and age-matched Wistar-Kyoto (WKY) animals. There was no difference in the kinetics of S6 kinase activation in the two cultures, but later metabolic events associated with proliferation were stimu...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/4.2.183
更新日期:1991-02-01 00:00:00
abstract::Most antihypertensive drugs act by counteracting vasoconstrictor mechanisms and lower blood pressure by lowering vascular resistance. The beta-blockers, which have the unique feature of counteracting cardiac sympathetic drive, seem to be a major exception to this generalization. Moreover, their degree of cardiodepress...
journal_title:American journal of hypertension
pub_type: 杂志文章,评审
doi:10.1093/ajh/1.1.91
更新日期:1988-01-01 00:00:00
abstract:BACKGROUND:Seventeen percent of youth in the United States are obese. Obesity has been linked to higher prevalence of hypertension. Past studies were limited by their size and conflicting results. The aim of this study was to analyze trends in adolescents' obesity between 1998 and 2011 and to evaluate the relationship ...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/hpv007
更新日期:2015-09-01 00:00:00
abstract:BACKGROUND:The collateral circulation is important in maintenance of blood supply to the ischemic kidney distal to renal artery stenosis (RAS). Obesity metabolic syndrome (MetS) preserves renal blood flow (RBF) in the stenotic kidney, but whether this is related to an increase of collateral vessel growth is unknown. We...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/hpy127
更新日期:2018-11-13 00:00:00
abstract::A negative calcium balance has previously been described in human hypertension with low levels of plasma ionized calcium (Ca2+) and an increased urinary excretion of calcium. The cause of this disturbance in mineral metabolism is not known, nor is it known if this derangement could be abolished if blood pressure is re...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/7.4.302
更新日期:1994-04-01 00:00:00
abstract:BACKGROUND:Blood pressure (BP) responses to dietary sodium and potassium intake vary among individuals. We examined the correlation between BP responses to dietary low-sodium, high-sodium, and potassium supplementation interventions in a feeding study. METHODS:A total of 1,906 Chinese aged > or = 16 years participated...
journal_title:American journal of hypertension
pub_type: 临床试验,杂志文章,多中心研究
doi:10.1038/ajh.2009.176
更新日期:2009-12-01 00:00:00
abstract::To evaluate the reactivity to psychological stress in patients with essential hypertension we investigated hemodynamic and endocrinologic changes during a mental arithmetic task (MAT) and a mirror drawing test (MDT) in 10 hypertensive subjects. Hemodynamic changes were assessed continuously using an ambulatory radionu...
journal_title:American journal of hypertension
pub_type: 临床试验,杂志文章
doi:10.1016/s0895-7061(96)00382-2
更新日期:1997-03-01 00:00:00
abstract:BACKGROUND:Hypertension is a risk factor for coronary heart disease (CHD), but the causes of hypertension remain largely unknown. Genetic variation is thought to contribute to the etiology of hypertension. We tested a single-nucleotide polymorphism (SNP) (Lys67Arg, rs197922) in the Golgi SNAP Receptor Complex Member 2 ...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1038/ajh.2008.336
更新日期:2009-02-01 00:00:00
abstract::In an in-depth examination to better define the renal effects of mild hypertension, we used urinary proteins to indicate damage to the glomerulus (albumin), tubular reabsorption capability (retinol-binding protein), and turnover of tubular tissue (alanine aminopeptidase and N-acetyl-beta-D-glucosaminidase) in a group ...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/0895-7061(95)00231-d
更新日期:1995-11-01 00:00:00
abstract::Abnormal calcium metabolism has been implicated in human hypertension. Caffeine consumption may contribute to hypertension since it increases urinary calcium excretion. Nineteen hypertensive subjects (HTN) and nineteen age and gender matched normotensive controls (NTC) who habitually consumed at least 175 mg caffeine ...
journal_title:American journal of hypertension
pub_type: 临床试验,杂志文章
doi:10.1016/0895-7061(95)00337-1
更新日期:1996-03-01 00:00:00
abstract::Recent works have shown the importance of blood pressure (BP) response to exercise or to daily activity as determinants of hypertensive cardiac hypertrophy. We have tested the relationship between BP and left ventricular (LV) mass in 23 normotensive young adults (mean age 25 +/- 5) with normotensive parents. Blood pre...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/2.2.78
更新日期:1989-02-01 00:00:00
abstract:BACKGROUND:It is unknown whether the physiological impact of a given blood pressure (BP) varies by body size. We explored interactions between higher vs. lower systolic BP (SBP) targets and anthropometric measures (body mass index (BMI), body surface area (BSA), height, weight) and recurrent stroke and death in the Sec...
journal_title:American journal of hypertension
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1093/ajh/hpu228
更新日期:2015-06-01 00:00:00
abstract:BACKGROUND:Vitamin D is involved in blood pressure (BP) regulation. Genetic variations may influence the effect of vitamin D on BP, but data from epidemiologic studies remain inconsistent. METHODS:We conducted a comprehensive genetic association study in the Women's Genome Health Study (WGHS) with genome-wide genotype...
journal_title:American journal of hypertension
pub_type: 杂志文章,meta分析
doi:10.1093/ajh/hpu049
更新日期:2014-11-01 00:00:00
abstract::Patients with hypertension tend to be glucose intolerant, hyperinsulinemic, and dyslipedemic. Since all of these changes increase risk of coronary heart disease (CHD), it is important to know what effect antihypertensive treatment has on these variables. The current open-labelled, uncontrolled study was initiated in o...
journal_title:American journal of hypertension
pub_type: 临床试验,杂志文章
doi:10.1093/ajh/5.8.506
更新日期:1992-08-01 00:00:00
abstract::Intracellular free sodium levels ([Na+]i) were assessed with 23Na nuclear magnetic resonance (NMR) spectroscopy in isolated, Langendorff-perfused normal, compensated hypertrophied, and hypertrophied failing guinea pig hearts under several conditions. Baseline [Na+]i measured with a shift reagent was significantly grea...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/0895-7061(95)00219-F
更新日期:1995-09-01 00:00:00
abstract:BACKGROUND:Left ventricular (LV) concentric geometry and hypertrophy, depressed wall mechanics, and abnormal diastolic properties have been described in the diabetic heart. However, the cardiac response to dynamic exercise in diabetic patients remains controversial. The present study assessed strain rate (SR) imaging d...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/j.amjhyper.2006.12.009
更新日期:2007-05-01 00:00:00
abstract:BACKGROUND:Few population studies have described the heritability and intrafamilial concordance of the retinal microvessels, or the genetic or environmental correlations of the phenotypes of these vessels. METHODS:We randomly selected 413 participants from 70 families (mean age, 51.5 years; 50.1% women) from a Flemish...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/hps064
更新日期:2013-03-01 00:00:00
abstract::Among the major mechanisms controlling the renal release of renin, renal nerves are known to exert a direct stimulating action on juxtaglomerular cells that is mediated by beta-adrenoceptors. Activation of the renal nerves also exerts an important permissive role in order to amplify and possibly accelerate responses t...
journal_title:American journal of hypertension
pub_type: 杂志文章,评审
doi:10.1093/ajh/2.2.7s
更新日期:1989-02-01 00:00:00
abstract:BACKGROUND:Endothelium-dependent vascular relaxation is impaired in various disease states including hypertension. METHODS:We investigated whether a single bolus dose of clofibrate could rapidly reverse saline-induced endothelial dysfunction, in vivo, in salt-loaded Sprague-Dawley (S-D) rats. S-D rats, 5 weeks of age,...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/j.amjhyper.2006.04.005
更新日期:2006-11-01 00:00:00
abstract:BACKGROUND:The morbidity and mortality benefits of blood pressure (BP) control for the elderly is well documented. The cognitive consequences of hypertension control in this population, however, are still under debate. We aim to study the association between BP and cognitive performance in the elderly. Specifically, we...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/s0895-7061(03)01005-7
更新日期:2003-10-01 00:00:00
abstract:BACKGROUND:Home blood pressure measurement (HBPM) is recommended by hypertension guidelines, particularly in the elderly. However, feasibility of HBPM in this age group has not been fully established. Our objective was therefore to assess HBPM feasibility in elderly individuals of the general population. METHODS:After...
journal_title:American journal of hypertension
pub_type: 杂志文章,多中心研究
doi:10.1038/ajh.2012.121
更新日期:2012-12-01 00:00:00
abstract:BACKGROUND:Central aortic blood pressure (CBP) and CBP-derived parameters are independent predictors of cardiovascular risk. Angiotensin II receptor blockers (ARBs) or angiotensin-converting enzyme inhibitors plus calcium channel blockers are the recommended first-line treatments in hypertensive diabetic patients; howe...
journal_title:American journal of hypertension
pub_type: 杂志文章,随机对照试验
doi:10.1093/ajh/hpw033
更新日期:2016-09-01 00:00:00
abstract:BACKGROUND:Although a hypertensive response to exercise (HRE) is associated with cardiac risk and masked hypertension (MHT), its mechanisms and appropriate treatment remain unclear. We investigated spironolactone as a treatment for abnormal vascular and myocardial stiffness in HRE. METHODS:In this randomized, double-b...
journal_title:American journal of hypertension
pub_type: 杂志文章,随机对照试验
doi:10.1093/ajh/hpt008
更新日期:2013-05-01 00:00:00
abstract:BACKGROUND:Prenatal lipopolysaccharide (LPS) exposure causes hypertension in rat offspring through an unknown mechanism. Here, we investigated the role of the intrarenal renin-angiotensin system (RAS) in hypertension induced by prenatal LPS exposure and also explored whether adipose tissue-derived mesenchymal stem cell...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/hpx117
更新日期:2017-11-06 00:00:00
abstract::Several classes of antihypertensive drugs have been shown to improve vascular function through mechanisms other than reducing blood pressure (BP) alone. Certain dihydropyridine calcium channel blockers (CCBs) and inhibitors of the renin-angiotensin system (RAS) increase nitric oxide (NO) bioavailability and decrease o...
journal_title:American journal of hypertension
pub_type: 杂志文章,评审
doi:10.1038/ajh.2008.258
更新日期:2008-10-01 00:00:00
abstract::Three hundred eight outpatients referred for hypertension were studied. A continuous beat-to-beat noninvasive recording (Finapres) of blood pressure evaluated the blood pressure increase (9 mm Hg systolic and 4 mm Hg diastolic) induced by office sphygmomanometry. Thereafter, patients underwent a 24-h ambulatory blood ...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/0895-7061(95)00354-1
更新日期:1996-04-01 00:00:00
abstract::Time-related changes in plasma levels of aldosterone, deoxycorticosterone, corticosterone, and cortisol were studied during treatment with spironolactone in 8 patients with primary aldosteronism due to adenomas. Plasma renin activity (PRA), serum sodium and serum potassium were also measured. The patients were treated...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/3.7.533
更新日期:1990-07-01 00:00:00