Abstract:
:Antioxidant protection provided by different doses of alpha-tocopherol was compared by determining nitric oxide synthase (NOS) activity in blood vessels of spontaneously hypertensive rats (SHR) treated with alpha-tocopherol. SHR were divided into four groups namely hypertensive control (C), treatment with 17 mg of alpha-tocopherol/kg diet (alpha1), 34 mg of alpha-tocopherol/kg diet (alpha2), and 170 mg of alpha-tocopherol/kg diet (alpha3). Wister Kyoto (WKY) rats were used as normal control (N). Blood pressure were recorded from the tail by physiography every other night for the duration of the study period of 3 months. At the end of the trial, animals were sacrificed. The NOS activity in blood vessels was measured by [3H]arginine radioactive assay and the nitrite concentration in plasma by spectrophotometry at wavelength 554 nm using Greiss reagent. Analysis of data was done using Student's t test and Pearson's correlation. The computer program Statistica was used for all analysis. Results of our study showed that for all the three alpha-tocopherol-treated groups, blood pressure was significantly (P < .001) reduced compared to the hypertensive control and maximum reduction of blood pressure was shown by the dosage of 34 mg of alpha-tocopherol/kg diet (C: 209.56 +/- 8.47 mm Hg; alpha2: 128.83 +/- 17.13 mm Hg). Also, NOS activity in blood vessels of SHR was significantly lower than WKY rats (N: 1.54 +/- 0.26 pmol/mg protein, C: 0.87 +/- 0.23 pmol/mg protein; P < .001). Although alpha-tocopherol in doses of alpha1, alpha2, and alpha3 increased the NOS activity in blood vessels, after treatment only that of alpha2 showed a statistical significance (P < .01). Plasma nitrite concentration was significantly reduced in SHR compared to normal WKY rats (N: 54.62 +/- 2.96 mol/mL, C: 26.24 +/- 2.14 mol/mL; P < .001) and accordingly all three groups showed significant improvement in their respective nitrite level (P < .001). For all groups, NOS activity and nitrite level showed negative correlation with blood pressure. It was significant for NOS activity in hypertensive control (r = -0.735, P = .038), alpha1 (r = -0.833, P = .001), and alpha2 (r = -0.899, P = .000) groups. For plasma nitrite, significant correlation was observed only in group alpha1 (r = -0.673, P = .016) and alpha2 (r = -0.643, P = .024). Only the alpha2 group showed significant positive correlation (r = 0.777, P = .003) between NOS activity and nitrite level. In conclusion it was found that compared to WKY rats, SHR have lower NOS activity in blood vessels, which upon treatment with antioxidant alpha-tocopherol increased the NOS activity and concomitantly reduced the blood pressure. There was correlation of lipid peroxide in blood vessels with NOS and nitric oxide, which implies that free radicals may be involved in the pathogenesis of hypertension.
journal_name
Am J Hypertensjournal_title
American journal of hypertensionauthors
Newaz MA,Nawal NN,Rohaizan CH,Muslim N,Gapor Adoi
10.1016/s0895-7061(99)00022-9subject
Has Abstractpub_date
1999-08-01 00:00:00pages
839-44issue
8 Pt 1eissn
0895-7061issn
1941-7225pii
S0895-7061(99)00022-9journal_volume
12pub_type
杂志文章abstract::Angiotensin II (Ang II) and transforming growth factor-beta (TGF-beta) modulate cell growth and metabolism. Our objective was to evaluate the effect of Ang II on the characteristics and expression of TGF-beta receptors on vascular smooth muscle cells (VSMC) from Wistar-Kyoto rats. The addition of TGF-beta1 elicited a ...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/s0895-7061(99)00152-1
更新日期:2000-02-01 00:00:00
abstract::Leptin, the gene product of the ob gene, is influenced by gender and insulin sensitivity. Because in human hypertension there are important endocrine-hemodynamic gender-dependent differences, we compared plasma leptin in 39 essential hypertensives (EH) and in 27 normotensive healthy subjects (HS) matched for gender, a...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/s0895-7061(00)00263-6
更新日期:2000-08-01 00:00:00
abstract::Calcitonin gene-related peptide (CGRP), a highly potent vasodilator, is expressed from the calcitonin-gene and has been localized to nerve fibers of the cardiovascular system, suggesting involvement in the physiologic regulation of vascular tone. In this investigation serum concentrations of CGRP were measured in pati...
journal_title:American journal of hypertension
pub_type: 杂志文章,评审
doi:10.1093/ajh/4.7.565
更新日期:1991-07-01 00:00:00
abstract:BACKGROUND:Peripheral endothelial dysfunction has been demonstrated in hypertension. However, its relationship to blood pressure (BP) load, vascular structure, and metabolic disturbances in patients with long-standing, previously treated hypertension is unclear. METHODS:A total of 41 patients with stage I to III essen...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/s0895-7061(01)02148-3
更新日期:2001-09-01 00:00:00
abstract::To clarify the function of polymorphonuclear leukocytes (PMN) in spontaneously hypertensive rats (SHR) and the effect of beraprost sodium (BS) on these functions, we examined superoxide anion (O2-) production and adherent activity by PMN, as well as modification of these functions by BS ex vivo and in vitro. In study ...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/s0895-7061(01)01309-7
更新日期:2001-07-01 00:00:00
abstract:BACKGROUND:The present study examined the inhibitory action of temporary treatment with an angiotensin type 1 (AT(1)) receptor blocker (ARB) on vascular remodeling using hypertensive mice with overexpression of the human renin (hRN) and angiotensinogen (hANG) genes. METHODS:hRN/hANG transgenic mice (hRN/hANG-Tg) were ...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1038/ajh.2011.6
更新日期:2011-05-01 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: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:BACKGROUND:Schlager inbred hypertensive mice (BPH/2J) have been suggested to have high blood pressure (BP) due to an overactive sympathetic nervous system (SNS). The brain nuclei associated with the hypertension are also those involved in the integration of the cardiovascular responses to stress. Therefore, in the pres...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1038/ajh.2010.69
更新日期:2010-08-01 00:00:00
abstract::The hypertensive transgenic rat model TGR(mRen2)27 has been used to investigate the development of cardiac and vascular hypertrophy in response to two different drug regimes. Cardiac hypertrophy was shown to be related to age and gender with the copy number of mouse renin transgenes having an additive effect. A simila...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/s0895-7061(99)00021-7
更新日期:1999-07-01 00:00:00
abstract:BACKGROUND:Previous reports have demonstrated the antihypertensive efficacy of high doses of spironolactone in subjects with primary aldosteronism and, to a lesser degree, subjects with resistant hypertension. METHODS:In current analysis, we examined the antihypertensive benefit of adding low-dose spironolactone to mu...
journal_title:American journal of hypertension
pub_type: 临床试验,杂志文章
doi:10.1016/s0895-7061(03)01032-x
更新日期:2003-11-01 00:00:00
abstract:BACKGROUND:Aortic pulse wave velocity (PWV) is a measure of arterial stiffness and has proved useful in predicting cardiovascular morbidity and mortality in several populations of patients, including the healthy elderly, hypertensives and those with end-stage renal disease receiving hemodialysis. Little data exist char...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1038/ajh.2009.240
更新日期:2010-03-01 00:00:00
abstract:BACKGROUND:Vitamin D deficiency in pregnancy has been associated with an increased risk of preeclampsia. However, the association between serum vitamin D and blood pressure in pregnant women has been scarcely evaluated, particularly in women with a high risk of developing hypertensive disorders of pregnancy. We sought ...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/hpu043
更新日期:2014-10-01 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::Antihypertensive drugs are often initiated and adjusted over a period of weeks to months. It is not clear whether the time and inconvenience of this approach is necessary. We studied whether or not drug adjustment over several days in the context of a physician-nurse team could produce a durable blood pressure benefit...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/s0895-7061(00)01273-5
更新日期:2001-04-01 00:00:00
abstract::The purpose of this double-blind, forced titration study was to compare the antihypertensive effect duration of candesartan cilexetil, which has a longlasting binding to the human AT1-receptor, to that of losartan on ambulatory BP (ABP) not only during the 24-h dosing interval but also during the day of a missed dose ...
journal_title:American journal of hypertension
pub_type: 临床试验,杂志文章,多中心研究,随机对照试验
doi:10.1016/s0895-7061(99)00142-9
更新日期:1999-12-01 00:00:00
abstract:BACKGROUND:Our aim was to assess whether home blood pressure (HBP) and ambulatory BP monitoring measurement (ABPM), in addition to office BP (OBP) predict changes of cardiovascular biomarkers during antihypertensive treatment. METHODS:Two hundred and fifty-two hypertensive patients (mean age, 68 years; men: 41%) under...
journal_title:American journal of hypertension
pub_type: 杂志文章,多中心研究
doi:10.1038/ajh.2011.229
更新日期:2012-03-01 00:00:00
abstract:OBJECTIVES:Central blood pressure (BP) can be used to define hypertension. A central BP approach may be more sensitive than a conventional brachial BP approach in detecting hypertension. We aimed to compare the 2 approaches in estimating the prevalence hypertension in a nationally representative population. METHODS:A ...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/hpx178
更新日期:2018-02-09 00:00:00
abstract:OBJECTIVE:To determine the effects of orthostatic hypotension (OH) measurement timing on its associations with dizziness, falls, fractures, cardiovascular disease (CVD), and mortality. METHODS:We analyzed OH measurements from the Action to Control Cardiovascular Risk in Diabetes BP trial, which evaluated two blood pre...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/hpz015
更新日期:2019-06-11 00:00:00
abstract::We have previously reported that weight gain induced by high-fat diet (HFD) leads to an increase in mean arterial pressure (MAP, +14%) and heart rate (HR, +31%) in the adult rabbit. In the present study, we tested the hypothesis that an increased activity of the sympathetic nervous system may contribute to the develop...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/s0895-7061(99)00267-8
更新日期:2000-05-01 00:00:00
abstract:BACKGROUND:The renal resistive index (RI) measured using Doppler ultrasonography has been used as a diagnostic tool in the daily work-up of kidney diseases. A better understanding of its relationship with preclinical organ damage may help in determining overall cardiovascular risk in hypertensive patients. METHODS:We ...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1038/ajh.2012.113
更新日期:2012-12-01 00:00:00
abstract:BACKGROUND:African-American men have stiffer arteries than white men at rest. We sought to test the hypothesis that reductions in stiffness after aerobic exercise may be attenuated in African-American (AA) men compared with white (W) men. METHODS:Twenty-four young men (age 22+/-1.0 years; 12 AA and 12 W) underwent mea...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/j.amjhyper.2007.03.015
更新日期:2007-08-01 00:00:00
abstract:BACKGROUND:Population-level sociologic studies have suggested that adverse societal conditions may affect fetal viability in a sex-specific manner and thereby modify the ratio of male vs. female babies. This concept suggests that there may exist certain physiologic features in a woman that relate to her likelihood of d...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/hpw165
更新日期:2017-04-01 00:00:00
abstract::Leptin may be a link in the relationship of obesity with hypertension. We evaluated associations of leptin with blood pressure (BP) in 54 normotensive and 114 hypertensive African American individuals. Plasma leptin was higher (P <.03) in hypertensive women than in normotensive women, although body mass index did not ...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/s0895-7061(02)03089-3
更新日期:2002-11-01 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::Vasodilation is impaired in various conditions, such as hypercholesterolemia and tobacco use. We evaluated brachial artery flow-mediated vasodilation (FMD) after blood pressure (BP) cuff occlusion using high-resolution B-mode ultrasound in 20 alcoholics, without any coexisting conditions such as smoking, hypertension,...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/s0895-7061(98)00173-3
更新日期:1999-02-01 00:00:00
abstract::We studied the role of the sympathetic nervous system and the renin angiotensin system for pressure induced left ventricular hypertrophy (LVH) in 135 rats with experimental supravalvular aortic stenosis (AS). We induced this condition by a silver clip on the ascending aorta, when body weight (BW) was 90 to 100 g. Symp...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1093/ajh/4.6.521
更新日期:1991-06-01 00:00:00
abstract:BACKGROUND:The angiotensin II type 1 receptor A1166C polymorphism has been associated with increased risks of hypertension and myocardial infarction in several small studies. We examined the association between this polymorphism and new-onset hypertension, blood pressure (BP) control, and incident cardiovascular events...
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(02)03063-7
更新日期:2002-12-01 00:00:00
abstract::To determine whether the benefits of antihypertensive treatment vary according to dipper status, 811 asymptomatic elderly Japanese hypertensives underwent 24-h ambulatory blood pressure monitoring. During a mean follow-up period of 41 months, 32 stroke events were observed in patients who remained nonmedicated (n = 38...
journal_title:American journal of hypertension
pub_type: 临床试验,杂志文章
doi:10.1016/s0895-7061(02)03020-0
更新日期:2002-10-01 00:00:00
abstract::The peak incidence of cardiovascular complications in the morning points to a possible role of the abrupt increase in blood pressure on arising. However, there is as yet no firm evidence linking the extent of the elevation in blood pressure on arising and the risk of cardiovascular complications. We sought a correlati...
journal_title:American journal of hypertension
pub_type: 杂志文章
doi:10.1016/s0895-7061(96)00048-9
更新日期:1997-05-01 00:00:00