Search Results
Results 301 - 350 of 1435
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Tomassoni Daniele - - 2003
Effects of treatment with equi-hypotensive doses of first-, second-, and third-generation dihydropyridine-type Ca2+ channel blockers on hypertension-dependent left ventricle hypertrophy and coronary vascular changes were assessed in spontaneously hypertensive rats (SHRs) by quantitative microanatomic techniques. Male SHRs were treated for 12 weeks with equi-hypotensive doses of nifedipine, isradipine, manidipine, amlodipine, ...
Rithalia A - - 2003
BACKGROUND: Halothane shortens ventricular action potential duration (APD), as a consequence of its inhibitory effects on a variety of membrane currents, an effect that is greater in sub-endocardial than sub-epicardial myocytes. In hypertrophied ventricle, APD is prolonged as a consequence of electrical remodelling. In this study, we compared the effects ...
Hirooka Yoshitaka - - 2003
Previously, we demonstrated that endothelial nitric oxide synthase (eNOS) gene transfer into the nucleus tractus solitarii (NTS) decreased blood pressure, heart rate and sympathetic nerve activity in conscious normotensive Wistar-Kyoto rats (WKY). In order to determine whether overexpression of eNOS in the NTS causes different effects on blood pressure and ...
Chen Tzy-Li - - 2003
Synthetic peptides were microencapsulated into liposomes, cycled with a disulfide bond or modified with d-phenylglycine (d-phg) at the N-terminal, and their antihypertensive effects as orally administered (0.18 mM/kg body weight) to spontaneously hypertensive rats (SHR) were measured. The microencapsulated Leu-Lys-Pro reduced significantly the systolic blood pressures of SHR by 45 ...
Sharma Jagdish N - - 2003
It is known that the tissue kallikrein-kinin system is located in the cardiac tissue, and the lack of this system in the cardiac tissue might induce cardiac dysfunctions. In this study, we investigated the potential role of tissue kallikrein and Trasylol, an inhibitor of tissue kallikrein, on survival time with ...
Cingolani Oscar H - - 2003
Hypertensive heart disease is characterized by early development of hypertrophy and fibrosis that leads to heart failure (HF). HF develops in spontaneously hypertensive rats (SHR) after 18 months; however, it is not clear whether hypertrophy leads to altered cardiac performance at an earlier age in these rats. We studied cardiac ...
Laurent P - - 2003
The blood pressure pattern in spontaneously hypertensive rats (SHRs) involves three main characteristics: increase in mean blood pressure (MBP); increase in thoracic aorta (proximal) and iliac (distal) pulse pressure (PP); disappearance of the normal PP amplification between the proximal and the distal arteries. Whether pharmacologic agents may reduce MBP with ...
Chu Yi - - 2003
Oxidative stress may contribute to hypertension. The goals of this study were to determine whether extracellular superoxide dismutase (ECSOD) reduces arterial pressure in spontaneously hypertensive rats (SHR) and whether its heparin-binding domain (HBD), which is responsible for cellular binding, is necessary for the function of ECSOD. Three days after intravenous ...
Welch William J - - 2003
BACKGROUND: The spontaneously hypertensive rat (SHR) has oxidative stress and enhanced O2 usage (Q(O2)) relative to tubular sodium transport (TNa). Angiotensin II (Ang II) acting on Type I receptors (AT1-R) causes renal oxidative stress and functional nitric oxide (NO) deficiency that could enhance O2 usage. Therefore, we investigated the hypothesis ...
Liu Ju-Chi - - 2003
Stevioside is a sweet-tasting glycoside isolated from the leaves of Stevia rebaudiana. It has been used as a noncaloric sugar substitute in Japan and Brazil for decades. Previous studies have shown that it lowered blood pressure in spontaneously hypertensive rats by intravenous injection. This study was designed to evaluate the ...
Lu Ze-An - - 2003
1. Hydrochlorothiazide mixture (HCTM) is widely used in China for the treatment of hypertension. This mixture consists of hydrochlorothiazide, triamterene, reserpine, hydralazine and chlordiazpoxide, with small (one-third to one-fifth of normal) doses of each drug. The present study was designed to investigate the effects of this mixture on blood pressure, ...
Mandarim-de-Lacerda Carlos Alberto - - 2003
The aim of this study was to evaluate the cardiac structure of spontaneously hypertensive rats (SHRs) treated with different doses of spironolactone. Twenty SHRs were separated into four groups and treated for 13 weeks, as follows: one control group and three spironolactone treatment groups receiving doses of 5, 10 or ...
Bayer Allison L - - 2003
Cardiomyocytes express several isoenzymes of protein kinase C (PKC), which as a group have been implicated in the induction of left ventricular hypertrophy (LVH) and its transition to heart failure. Individual PKC isoenzymes also require transphosphorylation and autophosphorylation for enzymatic activity. To determine whether PKC isoenzyme expression and autophosphorylation are ...
Rao Man-Ren - - 2002
Tetrandrine (Tet) is an alkaloid isolated from the Chinese herb Radix of Stephaniae tetrandrae S Moore. Cardiac and vascular remodeling confers a very definite risk of increased cardiovascular morbidity and mortality. Remodeling reversal has been achieved in human and experimental animals treated with some antihypertensive drugs but not all. This ...
Abraham N G - - 2002
Heme oxygenase (HO) is a microsomal enzyme that oxidatively cleaves heme to form biliverdin, releasing iron and carbon monoxide (CO). Thus, HO not only controls the availability of heme for the synthesis of hemeproteins but also generates CO, which binds to the heme moiety of hemoproteins, thereby affecting their enzymatic ...
Xie He-Hui - - 2002
AIM: To study the importance of reduction of blood pressure variability (BPV) in the organ protection of long-term treatment with combination of nitrendipine and atenolol, which was abbreviated as Nile, in spontaneously hypertensive rats (SHR). METHODS: Combination of nitrendipine (10 mg/kg/d) and atenolol (20 mg/kg/d) was given in SHR chow ...
Khan Imran M - - 2002
Spontaneously hypertensive rats (SHR) exhibit enhanced pressor, heart rate, and nociceptive responses to spinal nicotinic agonists. This accompanies a paradoxical decrease in spinal nicotinic receptor number in SHR compared with normotensive rats. The congenic strain, SHR-Lx, with an introgressed chromosome 8 segment from the normotensive Brown-Norway-Lx strain (BN-Lx) exhibits reduced ...
Ledingham Janet M - - 2002
1. The aims of the present study were, first, to determine whether, in the genetically hypertensive (GH) rat, fluvastatin would lower blood pressure and remodel mesenteric resistance arteries (MRA) and the basilar artery and, second, to see whether treatment with a combination of fluvastatin and the angiotensin receptor antagonist valsartan ...
Zhang Jian - - 2002
Rilmenidine is a second-generation centrally acting antihypertensive drug that acts mainly through the activation of the imidazoline (I(1)) receptor in the rostral ventrolateral medulla (RVLM). To investigate the contribution of the N-methyl-D-aspartate receptor (NMDAR) to the hypotensive action of rilmenidine, experiments were undertaken in conscious male spontaneously hypertensive rats (SHRs). ...
Vasdev S - - 2002
In spontaneously hypertensive rats (SHRs) excess endogenous aldehydes bind sulfhydryl groups of membrane proteins, altering membrane Ca2+ channels and increasing cytosolic free calcium and blood pressure. The thiol compound, N-acetyl cysteine, normalizes elevated blood pressure in SHRs by binding excess endogenous aldehydes. Vitamin E increases tissue glutathione levels--a storage form ...
Alemayehu Adamu - - 2002
The normotensive Wistar-Kyoto (WKY) rat strain is a traditional control for the spontaneously hypertensive rat (SHR). We found trait differences between two inbred normotensive WKY strains, derived originally from different vendors, and compared these two strains from La Jolla-Taconic Farms (WKY/lj-tf) and La Jolla-Charles River (WKY/lj-cr) with the inbred SHR/lj-cr ...
Abdelrahman Aly M - - 2002
This study examined the vasodilator action of nociceptin, an endogenous opioid receptor-like ligand (ORL1), in thiobutabarbital-anesthetized rats, via the triple-isotope microspheres technique. Nociceptin (10, 30 nmol/kg, left ventricular injection) reduced mean arterial pressure (-27, -29 mm Hg), total peripheral resistance (-36, -41% of baseline) and heart rate (-8, -11% of ...
Li Yuan - - 2002
We have previously shown that the enhanced expression of G(i) proteins in spontaneously hypertensive rats (SHR) that precedes the development of high blood pressure may be one of the contributing factors in the pathogenesis of hypertension. In the present study, we demonstrate that the inactivation of G(i) proteins by intraperitoneal ...
Sinert Richard - - 2002
Patients with essential hypertension (EH) have higher mortality rates from hemorrhage. How the complex physiologic changes seen in EH affect the response to uncontrolled hemorrhage has yet to be adequately described. OBJECTIVE: To test the null hypothesis that there would be no difference in the hemorrhage volumes and hemodynamic responses ...
Su Ding-Feng - - 2002
Arterial baroreflex (ABR) is a very important mechanism in the regulation of cardiovascular activities. As ABR function is largely inhibited by anesthesia, its measurement in conscious animal becomes important. The present review summarizes the works concerning ABR function in conscious rats completed in our department in the last 10 years. ...
Sakata Katsufumi - - 2002
Patients with a reduced nonlinear component of heart rate regulation have a poorer outcome. We investigated whether a nonlinear correlation between renal sympathetic nerve activity (RSNA) and blood pressure or renal blood flow is reduced in conscious, spontaneously hypertensive rats (SHR) by comparing them with normotensive Wistar-Kyoto rats (WKY). We ...
Bergström Göran - - 2002
OBJECTIVE: We studied the importance of regional vascular structural changes for the long-term antihypertensive effect of brief angiotensin II receptor blockade with losartan in young spontaneously hypertensive rats (SHRs). DESIGN/METHODS: SHRs were treated from 3 to 8 weeks of age with losartan (SHRLos, 30 mg/kg per day in drinking water) ...
Endemann Dierk - - 2002
This study examined the role of tyrosine kinase-dependent signaling pathways in arginine vasopressin (AVP)-induced contractile responses in resistance arteries from spontaneously hypertensive rats (SHR). Systolic blood pressure was measured in conscious 6- and 21-week old SHR and Wistar Kyoto rats (WKY) by tail cuff measurements. Segments of third-order mesenteric arteries ...
Touyz Rhian M - - 2002
Extracellular signal-regulated kinases (ERK1/2) modulate vascular smooth muscle cell (VSMC) growth and contractility, important factors in blood pressure regulation. In the present in vivo study, we investigated whether short-term inhibition of ERK1/2-dependent signaling pathways influences vascular function and blood pressure (BP) in spontaneously hypertensive rats (SHR). SHR and Wistar-Kyoto (WKY) ...
Alvarez Bernardo V BV Universidad Nacional de La Plata, La Plata, - - 2002
Sodium/hydrogen ion exchange is hyperactive in hypertension. Myocardial sodium/hydrogen ion exchange hyperactivity accompanies the regression of cardiac hypertrophy in spontaneously hypertensive rats (SHR) after long term control of blood pressure with enalapril. To explore whether this effect is shared by other antihypertensive agents or is specific to angiotensin-converting enzyme inhibition. ...
Yamada Yuko - - 2002
Ovokinin(2-7) (RADHPF), an orally active antihypertensive peptide derived from ovalbumin, lowers blood pressure in SHRs at a dose of 10 mg/kg. Attempts were made to potentiate its anti-hypertensive activity by replacing the amino acid residues in [Pro2, Phe3]-ovokinin(2-7), which was previously reported to have 33-fold stronger activity than ovokinin(2-7). The ...
Hayward Linda F - - 2002
We examined the effect of alpha(2)-adrenoreceptor blockade in the nucleus of the solitary tract (NTS) on baroreflex responses elicited by electrical stimulation of the left aortic depressor nerve (ADN) in urethane-anesthetized spontaneously hypertensive rats (SHR, n = 11) and normotensive Wistar-Kyoto rats (WKY, n = 11). ADN stimulation produced a ...
Bellenger-Germain S - - 2002
The aim of the present study was to investigate whether a mixture of dietary n-6 and n-3 PUFA could lower blood pressure in spontaneously hypertensive rats (SHR) of different ages. In addition, we studied how such a treatment could normalize the FA composition of plasma TAG and cholesterol esters (CE), ...
Ritter Oliver - - 2002
BACKGROUND: In animal models, increased signaling through the calcineurin pathway has been shown to be sufficient for the development of cardiac hypertrophy. Calcineurin activity has been reported to be elevated in the myocardium of patients with congestive heart failure. In contrast, few data are available about calcineurin activity in patients ...
Packer C Subah - - 2002
OBJECTIVES: To determine: 1) whether ovariectomy increases low-density lipoprotein (LDL) cholesterol; 2) if increased LDL cholesterol correlates with increased blood pressure; and 3) whether arterial muscle reactivity to the vasoactive oxidant hydrogen peroxide (H2O2) is gender-dependent in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). METHODS: SHR and WKY ...
Cosenzi Alessandro - - 2002
Enrasentan is an antagonist of endothelin (ET) receptors. Previous studies have shown that antagonism of ET receptors might represent a new approach to the treatment of hypertension. Rats with a high-fructose diet (HFD) develop hyperinsulinemia, hypertriglyceridemia, and hypertension; renal and cardiac damage. The aim of this study was to evaluate ...
Rao Sumangala P - - 2002
We tested the hypothesis that a single bout of dynamic exercise produces a postexercise hypotension (PEH) and alpha(1)-adrenergic receptor hyporesponsiveness in spontaneously hypertensive rats (SHR). The postexercise alpha(1)-adrenergic receptor hyporesponsiveness is due to an enhanced buffering of vasoconstriction by nitric oxide. Male (n = 8) and female (n = 5) ...
Roald Anca B - - 2002
Renal tissue damage is substantially more pronounced in the juxtamedullary than in the superficial cortex in hypertensive rats, and the pathogenesis of the morphological changes are only partly understood. Glomerular capillary pressure (P(GC)) is increased, and steady-state autoregulation is normal in the deep renal cortex. We tested the hypothesis that ...
Zdrojewski Tomasz - - 2002
The effect of ACE inhibition after myocardial infarction (MI) on MI healing and remodeling in the presence of hypertension is not exactly known. Therefore, the effect of quinapril on scar formation, remodeling and hemodynamics was studied in spontaneously hypertensive rats (SHR). Nine weeks after moderate and large MI, left ventricular ...
Yang Q - - 2002
Choto-san is a formula used for the treatment of headache and vertigo. Recently it has often also been used for hypertension and dementia. One of the mechanisms involved is thought to be the improvement of blood circulation, but the details are still unclear. In this study, the effect of Chotosan ...
Franco Maria do Carmo P Mdo - - 2002
Epidemiologic studies suggest that intrauterine undernutrition plays an important role in the development of arterial hypertension in adulthood. The aim of the current study was to evaluate whether severe nutritional restriction during pregnancy can aggravate hypertension, vascular reactivity changes, and renal development in spontaneously hypertensive rat (SHR) offspring. To investigate ...
Li Weimin - - 2002
OBJECTIVE: To explore the pathogenic changes of myocardial apoptosis in heart hypertrophy during hypertension and evaluate the anti-apoptosis effect of Valsartan. METHODS: Thirty spontaneously hypertensive rats (SHRs) were divided into two groups: 15 treated with Valsartan (20 mg x kg(-1) x d(-1)) (SHR + Valsartan group), the others with placebo ...
Lo Ming - - 2002
One or more quantitative trait locus (QTL) for blood pressure (BP) exists on rat chromosome 1, in the vicinity of the Sa gene. The present work examined whether this QTL region: 1) alters pressure-natriuresis relationship and 2) affects the BP response to salt load. Male spontaneously hypertensive rats (SHR), Wistar-Kyoto ...
Kishi Takuya - - 2002
We have previously demonstrated that the overexpression of endothelial NO synthase (eNOS) in the rostral ventrolateral medulla (RVLM) decreases blood pressure, heart rate, and sympathetic nerve activity via an increase in gamma-amino butyric acid release in normotensive Wistar-Kyoto rats (WKY). Stroke-prone spontaneously hypertensive rats (SHRSP) appear to have reductions of ...
Sipola Marika - - 2002
The effect of long-term intake of two fermented milk products on the development of hypertension was compared in young spontaneously hypertensive rats (SHR). The products contained tripeptides isoleucine-proline-proline (IPP) and valine-proline-proline (VPP), which have been shown to possess angiotensin converting enzyme (ACE) inhibitory activity. Six-week-old SHR were divided into four ...
Setoguchi Yuki - - 2002
Effects of long-term sarpogrelate (5-HT(2) antagonist) administration on the systolic blood pressure of Wistar-Kyoto normotensive rats (WKYs) and spontaneously hypertensive rats (SHRs) were studied and compared with those of quinapril (ACE-I). Sarpogrelate and quinapril were administered orally for 12 weeks and body and heart weights, systolic blood pressure and the ...
Raasch Walter - - 2002
Since agmatine has been identified as a clonidine displacing substance (CDS), the aim of this study was to investigate whether agmatine can mimic CDS-induced cardiovascular reactions in organ bath experiments, pithed spontaneously hypertensive rats (SHR) and anaesthetized SHR. Intravenously-administered agmatine significantly reduced the blood pressure and heart rate of anaesthetized ...
Han Shaojie - - 2002
Chronic treatment with Salvia Miltiorrhiza preventing left ventricular hypertrophy (LVH) and its possible mechanism--inhibiting the action of cardiac aldosterone in spontaneously hypertensive rats (SHR) were investigated. Normotensive Wistar-kyoto (WKY) rats and SHRs were used. Part of SHRs was treated with Salvia Miltiorrhiza for 12 weeks. Systolic blood pressure (SBP) and ...
Mizutani Ken-ichi - - 2002
The rostral ventrolateral medulla (RVLM) plays a critical role in the tonic and reflexive regulation of arterial blood pressure. Recent studies have demonstrated that injection of kynurenic acid (KYN) into the RVLM of spontaneously hypertensive rats (SHR) decreases arterial blood pressure. We hypothesized that a relative increase in the excitatory ...
Sato Minoru - - 2002
AIM: The angiotensin-I-converting enzyme (ACE) inhibitory and antihypertensive activities of wakame hydrolysates have been investigated in several studies. METHODS: Wakame (Undaria pinnatifida) was hydrolyzed using 17 kinds of proteases and the inhibitory activity of the hydrolysates for ACE was measured. Of these hydrolysates 4 with potent ACE inhibitory activity were ...
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