Abstract:
BACKGROUND:Ionized magnesium levels are elevated in fetal blood compared with maternal blood, suggesting that the placenta may possess an active transport mechanism for magnesium. In the present study, we sought to determine the existence of an active transport mechanism for magnesium in the placenta using cultured trophoblast cells. METHODS:Using choriocarcinoma cells as a model system, we attempted to demonstrate the presence of a functional Na+/Mg2+ exchanger. Human choriocarcinoma JEG-3 cells cultured on glass coverslips were loaded with MAG-Fura 2-AM (5 micromol/L x 30 min) to spectrofluorometrically assess kinetics of intracellular magnesium ([Mg2+]i). Cells were superfused with various concentrations of Na+, Mg2+, Ca2+ and imipramine, a blocker of erythrocyte Na/Mg exchange. [Mg2+]i calibration was determined via Triton X-100 and EDTA. RESULTS:Sequential lowering of extracellular Na+ caused progressively larger, transient increases in [Mg2+]i. These transient changes in [Mg2+]i were completely dependent on [Mg]o but was independent of extracellular calcium ([Ca]o). Although acute imipramine did not alter basal [Mg2+]i, imipramine eliminated the return-to-basal phase of the [Mg2+]i transient induced by low sodium medium. Increasing extracellular magnesium ([Mg]o) caused stepwise increases in [Mg2+]i. CONCLUSIONS:The JEG-3 cells appear to possess a functional Na/Mg exchanger that functions to maintain low [Mg2+]i in cytotrophoblast cells. In addition, [Mg2+]i is acutely regulated by [Mg]o. Because placental trophoblasts are sites of maternal-fetal ion exchange, and [Mg]o is altered in preeclampsia, derangements in or modulation of this exchanger may contribute to complications of pregnancy such as pregnancy-induced hypertension, pre-eclampsia, and preterm labor.
journal_name
Am J Hypertensjournal_title
American journal of hypertensionauthors
Standley PR,Standley CAdoi
10.1016/s0895-7061(02)02272-0subject
Has Abstractpub_date
2002-06-01 00:00:00pages
565-70issue
6eissn
0895-7061issn
1941-7225pii
S0895706102022720journal_volume
15pub_type
杂志文章abstract:BACKGROUND:The prognostic value of left ventricular (LV) concentric remodeling in essential hypertension, and particularly in uncomplicated mild hypertension, is not yet completely clear. We investigated cardiovascular outcome in uncomplicated mild hypertensive patients with normal LV geometry and LV concentric remodel...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/j.amjhyper.2004.06.016
更新日期:2004-11-01 00:00:00
abstract:BACKGROUND:Insulin resistance (IR) and the metabolic syndrome (MetS) may contribute to cardiovascular risk in chronic kidney disease (CKD). We examine the association between IR and vascular function in CKD. Furthermore, we define the prevalence of MetS and examine the association between defining MetS and vascular fun...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/hpt077
更新日期:2013-09-01 00:00:00
abstract:BACKGROUND:In patients free from overt cardiac disease, R wave in aVL lead (RaVL) is strongly correlated with left ventricular mass index (LVMI) assessed by transthoracic echocardiography. The aim of the present study was to extend this finding to other settings (cardiomyopathy or conduction disorders), by comparing EC...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/hpu268
更新日期:2015-08-01 00:00:00
abstract:BACKGROUND:Whether left ventricular (LV) geometric remodeling, as indexed by relative wall thickness (RWT), aggregates in families and is inherited independent of LV mass (LVM) and additional confounders is uncertain. METHODS:We determined whether RWT as assessed from 2D targeted M-mode echocardiography shows intrafam...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/hpu202
更新日期:2015-05-01 00:00:00
abstract::Nitric oxide synthase (NOS) blockade increases blood pressure (BP) and modifies glomerular and tubular function. Angiotensin II (AII) blockade restores glomerular and tubular function but does not lower BP. We measured plasma renin activity (PRA), plasma (AIIp), and kidney tissue (AIIk) AII with radioimmunoassay to in...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/s0895-7061(97)00123-4
更新日期:1997-10-01 00:00:00
abstract:BACKGROUND:We hypothesized that high-dose active vitamin D therapy in the form of alphacalcidol (α-calcidol), used to treat secondary hyperparathyroidism in chronic kidney disease, could lead to vascular calcification and accelerated progression of aortic stiffness. METHODS:We conducted an observational study in 85 pa...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/hpu057
更新日期:2014-11-01 00:00:00
abstract:BACKGROUND:We examined data from a cohort of Caucasian women for evidence of an association between serum vitamin D (25-hydroxyvitamin D (25(OH)D)) insufficiency and greater risk of systolic hypertension in the population-based longitudinal Michigan Bone Health and Metabolism Study (MBHMS). METHODS:The cohort includes...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1038/ajh.2010.226
更新日期:2011-03-01 00:00:00
abstract::Galanin is a 29-amino acid peptide and widely distributed in the brain, although its significance in the control of neural activities is undefined. In the present study, we describe the effects of galanin on the electrically evoked release of dopamine in the rat central nervous system. In addition, to elucidate a poss...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/s0895-7061(98)00168-x
更新日期:1998-12-01 00:00:00
abstract::Most ambulatory blood pressure monitoring (ABPM) studies have used a mechanical clock as the reference time, but there is no biologic background for assuming that midnight by the mechanical clock is zero hour by the biologic clock. The aim of this study was to determine the biologic zero hour as the zero reference tim...
journal_title:American journal of hypertension
pub_type: 临床试验,杂志文章
doi:
更新日期:1997-07-01 00:00:00
abstract::There is controversy over whether endothelial function is impaired in human essential hypertension. All studies to date have used measurements of forearm blood flow by plethysmography to assess endothelium-dependent vasodilation and endothelial function. In contrast to these studies, which have focused on resistance v...
journal_title:American journal of hypertension
pub_type: 临床试验,杂志文章
doi:10.1016/s0895-7061(96)00414-1
更新日期:1997-03-01 00:00:00
abstract:BACKGROUND:Altered diastolic filling is an important contributor to several cardiovascular disorders. Multiple lines of evidence suggest a genetic contribution to left ventricular (LV) diastolic filling; however, chromosomal locations harboring genes involved in impaired LV diastolic filling have not been reported. The...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/s0895-7061(02)02943-6
更新日期:2002-07-01 00:00:00
abstract::It has been speculated for some time that various antihypertensive medications may have a deleterious effect on respiration during sleep and thereby enhance the apparent association between hypertension and sleep apnea/hypopnea (SAH). However, there are few data to support this contention. The present study used a dou...
journal_title:American journal of hypertension
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1016/s0895-7061(96)00507-9
更新日期:1997-06-01 00:00:00
abstract::The role of an endogenous sodium pump inhibitor in the pathogenesis of hypertension has been reported in several papers. Unfortunately, because of the unknown structure and lack of biochemical characterization, some discrepancies have arisen. In this study we report a method to obtain extracts from human plasma that a...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/1.3.56s
更新日期:1988-07-01 00:00:00
abstract:BACKGROUND:The aim of our study was to investigate the control of hypertension (HT) in treated children using ambulatory blood pressure (BP) monitoring (ABPM). METHODS:We retrospectively reviewed all ABPM studies in our center. Controlled HT was defined as systolic and diastolic BP index (patients' BP divided by the 9...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1038/ajh.2011.218
更新日期:2012-03-01 00:00:00
abstract::Ambulatory blood pressure (BP) and heart rate (HR) were measured in a physically fit, normotensive postmenopausal African American woman, before and after 15 weeks of aerobic training. Mean BP, HR, and HR variability were normal at the outset and were further improved by training. Training had no effect on circadian B...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/s0895-7061(02)02973-4
更新日期:2002-09-01 00:00:00
abstract::Increased dietary K+ increases plasma [K+] and is linked to or associated with reduced mortality from stroke and reduced blood pressure in humans and animals. We hypothesized that physiologic increases in extracellular [K+] ([K]o) directly inhibit cultured vascular smooth muscle cell (VSMC) proliferation. Studies were...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/7.4.346
更新日期:1994-04-01 00:00:00
abstract::Angiotensin II (Ang II) plays important roles in the development of cardiovascular diseases including hypertension, renal diseases, cardiac hypertrophy, congestive heart failure, and ischemic heart disease. Angiotensin II exerts classic hemodynamic and renal effects, but it is also a local biologically active mediator...
journal_title:American journal of hypertension
pub_type: 杂志文章,评审
doi:10.1016/j.amjhyper.2005.05.005
更新日期:2005-09-01 00:00:00
abstract:BACKGROUND:Recently, some investigators have shown that telmisartan, an angiotensin II (Ang II)-receptor blocker (ARB), is a partial agonist of the peroxisome proliferator-activated receptor-gamma (PPAR-gamma). We investigate whether telmisartan improves cardiovascular remodeling associated with the production of endot...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1038/ajh.2008.27
更新日期:2008-05-01 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::This double-blind placebo controlled study investigated the antihypertensive and humoral effects of nifedipine capsules in patients with essential hypertension inadequately controlled (seated diastolic blood pressure greater than or equal to 95 mm Hg) by hydrochlorothiazide (HCTZ) alone. Nifedipine acutely (first dose...
journal_title:American journal of hypertension
pub_type: 临床试验,杂志文章
doi:10.1093/ajh/2.11.828
更新日期:1989-11-01 00:00:00
abstract:BACKGROUND:We investigated the effects of percutaneous transluminal renal angioplasty on left ventricular (LV) mass, and the impact of LV mass reduction on outcomes. METHODS:A total of 144 hypertensive patients with renal artery stenosis (RAS) (mean age 69 years; 22.2% fibromuscular dysplasia (FMD)) who underwent angi...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/hpaa036
更新日期:2020-05-21 00:00:00
abstract::In a retrospective study we investigated the effects of altering treatment of type II diabetes mellitus from insulin to tolazamide on weight and blood pressure. In 17 patients, weight decreased from 136 +/- 6 to 131 +/- 6% of ideal body weight (P = .01). Even though weight loss occurred, mean systolic blood pressure i...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/0895-7061(95)00046-R
更新日期:1995-05-01 00:00:00
abstract::To examine the effects of hypertension on renal graft function, we studied the clinical course of 144 kidney transplant recipients who had functioning grafts for three to 13 years. The patients were divided into three groups: normotensive (n = 32), controlled hypertensive (n = 49) and uncontrolled hypertensive group (...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/2.5.341
更新日期:1989-05-01 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:BACKGROUND:Hypertension varies in prevalence among race/ethnic groups in the United States. Within-ethnic group differences associated with acculturation have been less frequently examined. We studied the association of three measures of acculturation (language spoken at home, place of birth, and years living in the US...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/j.amjhyper.2006.09.025
更新日期:2007-04-01 00:00:00
abstract:BACKGROUND:Previous reports focused on the significant acute effects immediately after an earthquake on an increase in blood pressure (BP) assessed by ambulatory BP monitoring. However, there have been no data on the impact of environmental triggers on the long-term response to earthquake. METHODS:We analyzed the ambu...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/hpv044
更新日期:2015-12-01 00:00:00
abstract::Because left ventricular hypertrophy (LVH) is a strong risk factor for cardiac morbidity and mortality considerable interest has been generated concerning the possible effects of modifying LVH in hypertensive patients. In animal models disproportionate regression of left ventricular (LV) mass in relation to blood pres...
journal_title:American journal of hypertension
pub_type: 临床试验,杂志文章,评审
doi:10.1093/ajh/3.6.512
更新日期:1990-06-01 00:00:00
abstract:BACKGROUND:Epidemiologic analysis of family data on blood pressure (BP) is often compromised by the effects of antihypertensive medications. A review of numerous clinical trials that investigated the effects of BP-lowering medications is summarized here. METHODS:Published clinical trials, including 137 clinical trials...
journal_title:American journal of hypertension
pub_type: 杂志文章,meta分析
doi:10.1016/j.amjhyper.2005.01.011
更新日期:2005-07-01 00:00:00
abstract::The role of dietary salt and calcium on changes in cellular cation metabolism has been evaluated in 11 salt-sensitive hypertensive black adults maintained on the following four metabolic diets for 56 days, 14 days on each diet in a repeated measures format: 356 mg Ca-1000 mg sodium (NA); 356 mg Ca-4000 mg Na; 934 Ca-1...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/1.4.386
更新日期:1988-10-01 00:00:00
abstract:OBJECTIVE:The target levels of home-monitored blood pressure (BP) in patients with type 2 diabetes mellitus (T2DM) have not yet been established. We sought to examine the appropriate target home BP level in T2DM. METHODS:This is a subanalysis of the Japan Morning Surge-Home Blood Pressure (J-HOP) study. We enrolled 4,...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/hpu249
更新日期:2015-08-01 00:00:00