Search Results
Results 501 - 550 of 1435
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Dickhout J G - - 1998
The course of hypertension development in young spontaneously hypertensive rats (SHR) was studied by the measurement of changes in systolic blood pressure (BP), body weight, and heart rate (HR) at 2, 3, 4, and 6 wk of age. To achieve this, we compared inbreeding lines of SHR and Wistar-Kyoto rats ...
Hashimoto Y - - 1998
It is well-known that cardiac hypertrophy and arterial and renal dysfunction are serious complications of hypertension. Therefore, we investigated the chronic effects of 606A (2-propyl-3-[2'(1H-tetrazole-5-yl)biphenyl-4-yl]methyl-5-acetyl-4,5,6,7- tetrahydro imidazo [4,5-c]pyridine-4-carboxylic acid disodium salt), a novel AT1-receptor antagonist, on these complications of hypertension in stroke-prone spontaneously hypertensive rats (SHRSP) using Wistar Kyoto rats ...
Rauchová H - - 1998
The effect of chronic L-carnitine treatment on blood pressure and plasma lipids was studied in spontaneously hypertensive rats (SHR). L-Carnitine treatment for 6 weeks lowered significantly both the systolic and mean arterial pressure of SHR but its influence on diastolic and pulse pressure was only modest. L-Carnitine did not influence ...
St Lezin E - - 1998
To investigate whether molecular variation in the renin gene contributes to the greater blood pressure of spontaneously hypertensive rats (SHR) versus normotensive Brown Norway (BN) rats, we measured blood pressure in an SHR progenitor strain and an SHR congenic strain that are genetically identical except at the renin gene and ...
Chan P - - 1998
Stevioside is a sweet-tasting glycoside, composed of stevia, a diterpenic carboxylic alcohol with three glucose molecules, mainly used as a substitute for non-alcoholic sweetener. It has previously been shown to reduce blood pressure in studies in animals and human. The effect of intravenous stevioside on the blood pressure was studied ...
Adili F - - 1998
BACKGROUND: Photodynamic therapy (PDT), the light activation of photosensitizer dyes for the production of free radicals, effectively inhibits experimental intimal hyperplasia with systemic administration of the photosensitizer. The local application of the photosensitizer directly into a vascular lesion to avoid systemic side effects and tightly control dose administration has theoretical ...
Bushehri N - - 1998
A gradual increase in blood pressure (BP), often attaining hypertensive levels, is common during aging--"age-related hypertension." Therefore, means to prevent or ameliorate this elevated BP safely are important. Although oral B-nicotinamide adenine dinucleotide (NADH), a natural coenzyme, is used principally to treat various neurologic disorders, we wished to investigate whether ...
Reckelhoff J F - - 1998
Studies were performed in intact male and female, gonadectomized male and female, and gonadectomized female rats given testosterone for 5 weeks to investigate the role played by testosterone in altered blood pressure control and pressure-natriuresis in male SHR. Serum testosterone levels reached a peak at 12 weeks of age in ...
Martin D S - - 1998
The initial stages of hypertension in the spontaneously hypertensive rat (SHR) are characterized by an increase in cardiac output. Venous capacitance plays an important role in the control of cardiac output. This study tested the hypothesis that venous tone is elevated in the developmental stages of spontaneous hypertension. Male SHR ...
Sharifi A M - - 1998
There is some evidence that the endothelin (ET) system may participate in blood pressure elevation and in vascular hypertrophy in stroke-prone spontaneously hypertensive rats (SHR-SP). To further understand the involvement of the ET system in this hypertensive model, we examined preproendothelin-1 (preproET-1) mRNA abundance in blood vessels of 5-week and ...
Miki S - - 1998
To determine whether the vasoconstrictor response to endothelin-1 (ET-1) is altered in coronary vessels of hypertensive hearts and the role of ETA and ETB receptors in these responses to ET-1, the vasoconstrictor response to ET-1 in coronary vessels was measured with or without ETA and ETB receptor antagonists. In isolated ...
Yokogoshi H - - 1998
The effect of gamma-glutamylmethylamide(GMA), one of the components of green tea extract, on the blood pressure in spontaneously hypertensive rats (SHR) was investigated. The effect of glutamic acid and r-glutamylethylamide (theanine), which is structurally similar to GMA, was also examined. When SHR were injected with glutamic acid (2000mg/kg), the blood ...
Seki T - - 1997
Although carbon monoxide (CO) has been suggested to be involved in the regulation of cardiovascular function through activation of soluble guanylyl cyclase, the pathophysiological significance in hypertension remains unknown. We therefore examined the effects of heme oxygenase (HO) inhibitor zinc protoporphyrin IX (ZnPP-IX) on blood pressure and determined HO mRNA ...
Zanchi A - - 1997
BACKGROUND: We had previously demonstrated that the distensibility of the carotid artery in spontaneously hypertensive rats (SHR) aged 18 weeks does not differ from that of the carotid artery in normotensive animals for common pressure levels, despite vascular hypertrophy in SHR. OBJECTIVE: To examine the time-course effects of hypertension on ...
Chao J - - 1997
Adrenomedullin (ADM) is a potent vasoactive peptide. In this study, we explored the effects of a continuous supply of ADM by somatic gene delivery on spontaneously hypertensive rats (SHR). DNA constructs containing the human ADM cDNA fused to either the cytomegalovirus promoter (CMV-cADM) or Rous Sarcoma virus 3'-long terminal repeat ...
Nakano N - - 1997
Hepatocyte growth factor (HGF) is a mesenchyme-derived pleiotropic factor that regulates cell growth, cell motility, and morphogenesis of various types of cells, and is thus considered a humoral mediator of epithelial-mesenchymal interactions responsible for morphogenic tissue interactions. We have previously reported that HGF is a novel member of endothelium-specific growth ...
Stella M L - - 1997
OBJECTIVE: In essential hypertension, the mechanical properties of the radial artery have been shown to be largely unaltered, whereas more controversial and less reliable data have been obtained for the common carotid artery. We therefore examined the distensibility/pressure relationships of the predominantly elastic common carotid artery and of the predominantly ...
Gillies L K - - 1997
The effects of chronic treatment with an AT1 receptor antagonist (L-158,809) on hypertension development and cardiovascular changes were studied in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). L-158,809 treatment (0.6 mg/kg PO) was initiated at 3 weeks of age and lasted 12 weeks, to 15 weeks of age. The ...
Arribas S M - - 1997
Cellular aspects of remodeling in intact arteries have not been fully investigated, mainly due to the lack of an appropriate methodology that allows for simple measurements. The aim of this study was to develop a method based on laser scanning confocal microscopy (LSCM), compare it with previous methodology, and apply ...
Passmore J C - - 1997
Many vasoactive elements are involved in the elevation of blood pressure in spontaneously hypertensive rats (SHR). Elevated dietary calcium has been observed to reduce blood pressure in SHR. This study investigates interactions among dietary calcium, renal vascular resistance (RVR), elevation of blood pressure and effects of norepinephrine and nitric oxide ...
Díez J - - 1997
Increased apoptosis has been reported in the heart of rats with spontaneous hypertension and cardiac hypertrophy. This study was designed to investigate the relationship between apoptosis and hypertrophy in cardiomyocytes from the left ventricle of spontaneously hypertensive rats (SHR). In addition, we evaluated whether the development of cardiomyocyte apoptosis is ...
Benetos A - - 1997
We previously showed that chronic angiotensin-converting enzyme (ACE) inhibition prevented the increase in aortic collagen in spontaneously hypertensive rats (SHRs) independently of blood pressure reduction. The aim of the present study was to determine whether the effects of ACE inhibition on aortic fibrosis were due to inhibition of angiotensin II ...
Irvine R J - - 1997
We examined the influence of procedures used in blood pressure measurement on blood pressure and the effects of antihypertensive agents. Subjects were spontaneously hypertensive rats (SHR) and their Wistar/Kyoto (WKY) controls. Blood pressure was recorded by telemetry. Twenty-four h baseline pressure were measured, and the effect of minor handling on ...
Iliskovic N - - 1997
Adriamycin, an effective anticancer chemotherapeutic agent, causes an insidious and delayed cardiotoxicity. Different subcellular abnormalities including calcium transport changes in the sarcolemma (SL) as well as downregulation of the adrenergic system have been shown to be associated with the development of this cardiomyopathy. Since both of these activities are influenced ...
Yang C M - - 1997
OBJECTIVE: Excessive deposition of collagen has been implied to be responsible for abnormal stiffness and altered cardiac function during hypertrophy and heart failure. In the present paper we studied the changes in collagen and their phenotypes during development of cardiac hypertrophy in spontaneously hypertensive rats (SHR) compared to age- and ...
Jiang J - - 1997
The present study evaluated the effects of lovastatin on renal function and the development of hypertension in spontaneously hypertensive rats (SHR). Four-week-old SHR were given lovastatin (10 mg/kg) or vehicle twice daily by gavage. After 4 weeks of treatment, mean arterial pressure was significantly lower in lovastatin-treated SHR (131 +/- ...
Sutoo D - - 1997
The effects of calcium on blood pressure regulation remain controversial. Although the mechanism by which calcium increases blood pressure when it is given intravenously and acutely has been elucidated, that by which calcium reduces blood pressure when it is supplemented chronically and slightly through daily diet is unclear. From a ...
Kovács P - - 1997
In this study the spontaneously hypertensive rat (SHR/Mol) and the spontaneously diabetic BB/OK rat were crossed, and the F1 hybrids were backcrossed onto the BB/OK rat in order to search for cosegregation between blood pressure and loci on chromosomes 4 and 13. Cosegregation of microsatellites on chromosomes 4 (Spr, Npy, ...
Petersson M - - 1997
The aim of the present study was to investigate the effects of repeated injections of oxytocin on blood pressure and heart rate in spontaneously hypertensive rats (SHR). For this purpose subcutaneous (s.c.) injections of oxytocin 1 mg/kg or saline were given for 5 days to male and female SHR. Blood ...
Balakrishnan S M - - 1997
Changes in blood pressure, cardiac output, and total peripheral conductance evoked by intravenous infusions of [Arg8]-vasopressin (vasopressin) were recorded before and after pretreatment with bosentan, a non-selective endothelin antagonist, in conscious unrestrained spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). The presser effects of vasopressin were exaggerated in SHR compared ...
Machkov V V - - 1997
Vasoconstrictor effects of noradrenaline were compared in 6- to 7-month-old spontaneously hypertensive (SHR) and Wistar Kyoto (WKY) rats. A cylindrical segment was dissected from the proximal part of tail artery, cannulated at both ends and perfused alternately either at constant flow or constant pressure. Two series of experiments were performed. ...
Black M J - - 1997
OBJECTIVE: To examine the role played by angiotensin II (AII) in the development of prehypertensive vascular hypertrophy in the spontaneously hypertensive rat (SHR) and to determine whether normalization of prehypertensive vascular hypertrophy attenuates the development of hypertension. DESIGN: Male SHR and Wistar-Kyoto (WKY) rats were treated from age 10 days ...
Rizzoni D - - 1997
The aim of this study was to evaluate the delayed effects of an angiotensin converting enzyme (ACE) inhibitor on blood pressure and on structural and functional alterations in mesenteric small resistance arteries of spontaneously hypertensive rats (SHR). The ACE inhibitor fosinopril (25 mg/kg/day) was administered according to three different schedules: ...
Kurashina T - - 1997
Adrenomedullin (ADM), a peptide with potent vasodilatory and natriuretic actions, is elevated in patients with essential hypertension. Because pharmacological doses of ADM result in renal vasodilation and natriuresis, it has been suggested that ADM may play a modulatory role in hypertension through potential actions on renal pressure natriuresis. However, it ...
Lin K F - - 1997
Endothelium-derived nitric oxide (NO) in peripheral vessels has been shown to modulate vascular resistance and blood pressure. We explored the effect of a continuous supply of human endothelial NO synthase (eNOS) on the blood pressure of spontaneously hypertensive rats (SHR) by somatic gene delivery. A DNA construct containing the human ...
Ono H - - 1997
The vascular compliance and contractility of vascular smooth muscle of rat freshly amputated hindlimbs and hindlimbs preserved at -1 degree C for 12, 24, 48, and 72 hr were evaluated using a fresh blood extracorporeal circulatory system. Vascular compliance was measured under physiologic circulatory conditions (blood pressure of the amputated ...
K-Laflamme A - - 1997
As interactions between the renin-angiotensin and sympathetic nervous systems have been suggested in the pathogenesis of hypertension, we wanted to investigate the effect of chronic renin-angiotensin blockade with losartan and enalaprilat on the sympathetic reactivity to hypotension and on the cardiac beta-adrenergic-coupled adenylyl cyclase pathway in 12-week-old Wistar-Kyoto rats (WKY) ...
Arnolda L - - 1997
There is substantial evidence for an activation of the sympathetic nervous system in man as well as in genetic models of hypertension, such as the spontaneously hypertensive rat (SHR), but we are only beginning to understand the central mechanisms that generate changes in sympathetic activity and elevate blood pressure (BP). ...
Dukacz S A - - 1997
Long-term angiotensin-converting enzyme inhibitor treatment has been shown to have a persistent antihypertensive effect in spontaneously hypertensive rats (SHR) long after discontinuation of treatment. To test the hypothesis that this persistent effect involves a shift in the pressure-natriuresis relation, we performed experiments in male, anesthetized SHR at 18 wk of ...
Harrap S B - - 1997
It has been proposed that cardiovascular hypertrophy precedes and contributes to the development of genetic hypertension. In a genetically segregating population we determined whether susceptibility to high blood pressure was associated with cardiovascular structural abnormalities in youth. In 9-week old male F2 rats derived from a cross of spontaneously hypertensive ...
Schiffrin E L - - 1997
1. Chronic treatment with a combined ETA/ETB endothelin receptor antagonist has been shown to reduce blood pressure in experimental rat models of hypertension in which endothelin-1 gene overexpression occurs in the walls of blood vessels, particularly small, resistance-sized arteries, but not in those genetic or experimental models of hypertension in ...
Li J S - - 1997
The structure and function of small arteries of different vascular beds in spontaneously hypertensive rats (SHRs) are altered relative to Wistar-Kyoto (WKY) control rats, and these differences may be blunted under treatment with angiotensin-converting enzyme inhibitors. To determine whether this effect of angiotensin-converting enzyme inhibitors was caused by the interruption ...
Talom R T - - 1997
The role of the endothelium-derived relaxing factor (EDRF), nitric oxide (NO), in the withdrawal-induced antihypertensive phenomenon (WAP) of arginine vasopressin (AVP) was studied in conscious unrestrained rats implanted with femoral arterial catheters for the measurement of arterial blood pressure. Cessation of a 3-h intravenous infusion of AVP (20 ng.kg-1.min-1) was ...
Lin A M - - 1997
The role of paramedian reticular nucleus (PRN), a structure effecting sympathetic inhibition, in the development of hypertension was investigated in young spontaneously hypertensive rats (SHR) and two age-matched normotensive rats, Wistar-Kyoto (WKY) and Sprague-Dawley rats (SD). Three different experimental manipulations, including electrical-lesioning, sham-operated and intact control, were performed in SHR, ...
Chao J - - 1997
The tissue kallikrein-kinin system has been postulated to play an important role in blood pressure regulation. Kallikreins are serine proteinases that release potent vasodilating kinin peptides from precursor kininogens by limited proteolysis. Our recent studies show that systemic delivery of the human tissue kallikrein gene into adult spontaneously hypertensive rats ...
Eyal S - - 1997
This research uses the diastolic decay constant (tau) to investigate the short term mechanism responsible for vasomotor control, mainly the alpha-sympathetic control system. Previous studies have shown that vasomotor control is altered in spontaneously hypertensive rats (SHR) preceding the phase of overt hypertension. The diastolic decay, according to the two ...
Gyurko R - - 1997
Antisense oligodeoxynucleotides (AS-ODN) can be designed to provide inhibition of a specific protein. Since angiotensin receptors are involved in blood pressure regulation we constructed AS-ODN to angiotensin II type-1 receptor (AT1) mRNA. When given centrally, the AS-ODN reduces blood pressure in spontaneously hypertensive rats (SHR) 24 h after injection. To ...
Yokoshiki H - - 1997
The presence of left ventricular hypertrophy (LVH) is associated with an increased incidence of arrhythmias. Our previous study on hypertrophied rat hearts has demonstrated that regression of LVH prevents ischemia-induced lethal arrhythmias. To elucidate the underlying mechanism of the reduced incidence of arrhythmias in regression of LVH, we examined electrophysiological ...
Dobesová Z - - 1997
Heart and kidney weight of newborn rats was studied in two progenitor strains (Brown Norway-BN, and spontaneously hypertensive rats-SHR) and in 31 recombinant inbred (RI) strains developed by inbreeding of F2 cross derived from these two progenitors. The relative weight of both organs was significantly higher in SHR newborns than ...
Di Meo S - - 1997
We studied the effect of in vivo administration of 3,3',5-triiodo-L-thyronine (L-T3) and other iodothyronines to thyroidectomized rats on the heart rate and electrophysiological properties, recorded in vitro, from papillary muscle fibres. The treatment with a daily substitutive L-T3 dose (3.7 nmoles/100 g body weight) for ten days was associated with ...
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