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Results 601 - 650 of 1435
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Chen D G - - 1996
AIM: To study whether the effect of captopril (Cap) on vascular structure and function may be seperated from its effect on blood pressure. METHODS: Captopril treatment (group Cap A and B, 20 and 100 mg.kg-1.d-1) was given to SHR rats during pregnancy, weaning, and up to 16 wk of age. ...
Wahlander H - - 1996
Therapy with angiotensin II-converting enzyme (ACE) inhibitors has been suggested to prevent cardiovascular hypertrophy in hypertension even in doses that are subantihypertensive. We investigated the effects of two different ACE inhibitors on blood pressure and cardiovascular changes during as well as after discontinuation of treatment in spontaneously hypertensive rats (SHR). ...
Mackintosh V S - - 1996
We wished to establish whether the haemodynamic changes accompanying alterations in blood pressure exert a direct effect on clearance of chylomicron-like emulsions. N-Nitro-L-arginine (NOLA) and endothelin-1 were used to increase the blood pressure of normotensive rats, sodium nitroprusside (NP) and calcitonin gene-related peptide (CGRP) were used to decrease the blood ...
Mills T M - - 1996
The present studies were designed to determine the role of reactive vascular smooth muscle in the regulation of blood flow into and out of the cavernous sinuses during penile erection in castrated and testosterone-treated animals. While the mean arterial pressure and intracavernosal pressure were continuously monitored, vasoactive drugs were injected ...
Ohno Y - - 1996
OBJECTIVE: To search for a genetic marker of the sarco(endo)plasmic reticulum Ca(2+)-dependent ATPase (SERCA) II gene in spontaneously hypertensive rats (SHRs) and to investigate differences in blood pressure and intracellular Ca2+ among some substrains of SHRs and Wistar-Kyoto (WKY) rats related to their SERCA II genotypes. DESIGN AND METHODS: The ...
Zhu S T - - 1996
We and other laboratories have reported that arterial baroreflex-mediated control of heart rate is blunted in spontaneously hypertensive rats (SHR) compared with normotensive controls. Recently, we reported that atrial natriuretic peptide (ANP) microinjected into the caudal nucleus tractus solitarii of SHR further blunts this defect. The present study tested the ...
Kapuscinski M - - 1996
OBJECTIVE: High blood pressure in spontaneously hypertensive rat (SHR) is associated with increased sympathetic innervation of key tissues, possibly as the result of increased nerve growth factor (NGF). The aim of this study was to test for genetic linkage of the NGF gene to high blood pressure. DESIGN: We studied ...
Sironi G - - 1996
The antihypertensive action of lercanidipine (CAS 132866-11-6, Rec 15/2375), a new 1,4-dihydropyridine (1,4-DHP) calcium entry blocker (CEB), was examined in spontaneously hypertensive rats (SHR) and renal hypertensive dogs after acute and repeated administration, in comparison to several reference 1,4-DHPs. In acute experiments in SHR, lercanidipine reduced diastolic blood pressure showing ...
Kumagai K - - 1996
Along with arterial blood pressure reduction, maintenance of the integrity of baroreceptor reflex function contributes to preserving end-organ function in the treatment of hypertensive patients. The purpose of this study was to investigate the effects of antihypertensive agents (trichlormethiazide, atenolol, nicardipine, and enalapril) on baroreceptor reflex function by comparing early ...
Sventek P - - 1996
Inhibition of nitric oxide synthase by L-arginine analogues is associated with elevation of blood pressure in rats. Deoxycorticosterone acetate (DOCA)-salt hypertensive rats and DOCA-salt-treated spontaneously hypertensive rats (SHR) overexpress the endothelin-1 gene in blood vessels, and this is associated with severe vascular hypertrophy, whereas SHR do not overexpress endothelin-1 and ...
Kren V - - 1996
The spontaneously hypertensive rat (SHR) is the most widely used animal model of human essential hypertension. In the SHR strain, as in humans, the high blood pressure is determined multifactorially. Analysis of genetically segregating populations, derived from SHR and normotensive inbred strains, enabled localization of quantitative trait loci (QTLs) responsible ...
Matsuoka H - - 1996
Nitric oxide inhibits proliferation and migration of vascular smooth muscle cells and contractility of cardiomyocytes in vitro. In spontaneously hypertensive rats (SHR), evidence suggests intrinsic abnormalities of the L-arginine-nitric oxide axis, such as low cGMP-dependent protein kinase in the heart and abnormal L-arginine metabolism. To investigate the in vivo effect ...
Van Liew J B - - 1996
The present study was undertaken to investigate whether the development of proteinuria in the borderline hypertensive rat (BHR) is influenced by the Y chromosome and to determine if the onset of proteinuria in the BHR is delayed when blood pressure is lowered with enalapril, an angiotensin I converting enzyme inhibitor. ...
Izzard A S - - 1996
To investigate myogenic tone during the developmental and established phases of hypertension, segments of distal (6th order) mesenteric arteries from spontaneously hypertensive rats (SHR) at 5 and 20 wk were isolated and pressurized in vitro and compared with vessels from age-matched Wistar-Kyoto (WKY) control animals. At 5 wk, tone was ...
Kett M M - - 1996
1. There is strong evidence for a renal basis to the development of hypertension in the spontaneously hypertensive rat (SHR). Alterations of the SHR renal vasculature, including the glomerulus, may be involved in the initiation and maintenance of hypertension in this animal model. 2. The arterial walls of pre-glomerular vessels ...
Zelezná B - - 1996
The influence of chronic angiotensin AT1 receptor blockade by specific antibody on the development of genetic hypertension was studied in young spontaneously hypertensive rats (SHR). The immunization of 4-week-old SHR with a small part of the angiotensin AT1 receptor molecule attenuated the development of hypertension in these animals. After five ...
Ziegler D - - 1996
Moxonidine is a second-generation, centrally acting antihypertensive drug with a distinctive mode of action. Moxonidine activates I1-imidazoline receptors (I1-receptors) in the rostroventrolateral medulla (RVLM), thereby reducing the activity of the sympathetic nervous system. Moxonidine leads to a pronounced and long-lasting blood pressure reduction in different animal models of hypertension, e.g., ...
Batt C M - - 1996
Normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) received aminopeptidase M (AmM) delivered into the paraventricular nucleus of the hypothalamus (PVN). Resulting changes in blood pressure were recorded in both anesthetized and alert animals. The findings indicate significant dose-determined decreases in blood pressure in members of both strains with SHR ...
McCarty R - - 1996
To examine the effects of the preweanling maternal environment on the development of adult blood pressure, individual spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) normotensive pups were reciprocally cross-fostered between mothers of the same or opposite strain. With this design, each SHR and WKY foster mother reared 7 of her own ...
Chen H I - - 1996
In long-term hypertension, hemodynamic alterations are associated with functional and structural changes in the cardiovascular system. The technique of arterial impedance spectral analysis has long been used to characterize the arterial hemodynamics of steady and pulsatile components in human hypertension. Although rats with spontaneous hypertension (SHR) are the most common ...
Privitera P J - - 1995
Microinjections of kallikrein, 0.5-2.0 units, in the rostral ventrolateral medulla (RVLM) of brain increased arterial pressure in Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). This effect was significantly greater in SHR. The kinin B2 receptor antagonist icatibant (Hoe 140) blocked the hypertensive responses to kallikrein in both groups and caused ...
Kobayashi T - - 1995
OBJECTIVE: This study was undertaken to clarify whether the myocardial dysfunction observed in the hypertensive heart is an intrinsic property of the myocyte or not. MATERIALS AND METHODS: We investigated left ventricular function and contractile function of myocytes from 30-week-old spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). We also ...
Markov M - - 1995
1. The aim of the present study was to examine the effects of isoteoline (IST), a new tetrahydroaporphine derivative, on the blood pressure and some of the components of renin-angiotensin-aldosterone system (RAAS) in spontaneously hypertensive rats (SHR). 2. After long-term treatment (14 days, 3 times daily) in a dose of ...
Amenta F - - 1995
1. The influence of hypertension and treatment with the dihydropyridine-type Ca2+ antagonist, nicardipine, on the structure of the kidney was assessed in spontaneously hypertensive rats (SHR) of 12 weeks of age. Treatment went for 8 weeks with a daily oral dose of 1 mg/kg of nicardipine. 2. Control SHR exhibited ...
Takemoto Y - - 1995
1. The regional vascular effects of a central injection of gamma-aminobutyric acid (GABA) in conscious spontaneously hypertensive rats (SHR) were compared with normotensive control rats (NCR), including Wistar-Kyoto rats (male, 10-20 weeks of age). One week or more after insertion of a cannula into the cisterna magna, an electromagnetic flow ...
Akagashi K - - 1995
1. We evaluated the protective effects of manidipine on spermatogenic damage induced by the hypertensive vascular changes in stroke-prone spontaneously hypertensive rats (SHRSP). 2. Blood pressure reached more than 250 mmHg in SHRSP at 15 weeks of age, and thereafter the hypertensive changes in testicular arterioles developed. Manidipine reduced both ...
Korner P I - - 1995
NEUROHUMORAL SYSTEMS AS SUPERCONTROLLERS: The brain and closely linked hormone systems play a crucial part in short- and long-term cardiovascular control and have many features of adaptive control systems. The cardiovascular control system is a multivariate system, while changes in environmental conditions often result in alterations in system parameters and ...
Taylor B K - - 1995
Spontaneously hypertensive rats (SHRs) are typically less responsive to phasic noxious stimuli than are their normotensive controls. Here, we used the formalin test to compare behavioral and cardiovascular responses to persistent noxious stimuli. Hindpaw formalin injection produced exaggerated flinching, arterial pressure and heart rate responses in SHRs, suggesting that abnormalities ...
Koletsky R J - - 1995
1. Obese SHR have lower blood pressures than lean littermates on ad libitum diets of standard rat chow and develop spontaneous progressive kidney disease with marked proteinuria, whereas lean SHR have only mild proteinuria. 2. On a high-salt diet, obese SHR show dramatic elevations in blood pressure accompanied by accelerated ...
Higashino H - - 1995
1. Depressor and pressor effects of endothelin-1, -2 and -3 in relation to hypertension were investigated in conscious WKY and SHRSP. 2. Changes of systolic arterial pressure to both depressor and pressor responses caused by three doses of endothelin-1, -2 or -3 (0.1, 0.3 and 1 nmol/kg) occurred to a ...
Lin K F - - 1995
Chronic infusion of atrial natriuretic peptide (ANP) has been shown to cause natriuresis, diuresis, and hypotension in rats and humans. We explored the effect of a continuous supply of ANP by somatic ANP delivery on genetically hypertensive rats. A DNA construct containing the human ANP gene fused to the Rous ...
Ichikawa M - - 1995
1. We investigated the effects of antihypertensive treatment (8 weeks) with four different agents (trichlormethiazide, atenolol, nicardipine and enalapril) on baroreceptor function in 28 week old spontaneously hypertensive rats (SHR) to measure aortic depressor nerve (ADN) activity. 2. Threshold pressure (Pth) of ADN activity was elevated and the gain sensitivity ...
Boutros A - - 1995
The frequency of chronic hypertension among cardiac surgery patients implies that experimental therapies that protect normotensive myocardium will be more clinically relevant if they also protect chronically hypertensive myocardium. We tested the effectiveness of three experimental therapies that protect normotensive myocardium from ischemic injury in both normotensive (NTR) and spontaneously ...
Amenta F - - 1995
1. The effect of long-term treatment with the dihydropyridine Ca2+ antagonist, nicardipine, on the morphology of different sized pial arteries was assessed in spontaneously hypertensive rats (SHR) using histological techniques associated with image analysis. 2. In control 20 week old SHR blood pressure values, the thickness of the tunica media, ...
Ito M M Second Department of Medicine, Nihon University School of Medicine, Tokyo, - - 1995
To evaluate the long-term effects of an angiotensin-converting enzyme inhibitor (ACEI) on vascular angiotensin II (AII), eicosanoid production and vascular reactivities, we treated spontaneously hypertensive rats (SHR) with alacepril for 6 weeks and perfused the isolated mesenteric arterial bed which contains resistance vessels. Alacepril significantly lowered the arterial blood pressure. ...
Tanaka M - - 1995
OBJECTIVE: To investigate the cardiovascular effects of adenosine A2 receptor stimulation in the nucleus tractus solitarius and whether these effects are altered in hypertension. DESIGN AND METHODS: Ten- or 11-week-old spontaneously hypertensive rats (SHR) or Wistar-Kyoto (WKY) rats were anaesthetized with urethane. Adenosine (100 ng) or adenosine A2 agonist (2-octynyladenosine, ...
Suzuki H - - 1995
This study is designed to explore the effect of adrenal glucocorticoids on arteriolar behavior under steady state conditions in spontaneously hypertensive rats (SHR) compared with their normotensive controls, the Wistar Kyoto (WKY) rats. Mesenteric arterioles were observed by intravital microscopy under general anesthesia and arteriolar diameters were measured. At the ...
Burrell L M - - 1995
Abnormalities of the vasopressin system are found in genetic hypertension. This study compares the delayed effects of a brief period of vasopressin V1A receptor blockade and angiotensin-converting enzyme inhibition in young female and male spontaneously hypertensive rats (SHR) on the development of hypertension in adult life. In a separate study, ...
Stasch J P - - 1995
The cardiovascular consequences of endothelin (ET) blockade with the ETA-receptor antagonist FR 139317 were evaluated by determining the long-term effects of the drug on hemodynamic, hormonal, renal and structural parameters in stroke-prone spontaneously hypertensive rats (SHR-SP). Young SHR-SP on a high-sodium diet develop malignant hypertension accompanied by renovascular and cerebrovascular ...
Shimosawa T - - 1995
In the present study, we investigated the change in renal hemodynamics induced by a calcium antagonist in young (6 week-old) spontaneously hypertensive rats (SHR), a salt-sensitive hypertensive model. In acute experiments, SHR were fed either a 0.66% or 8.0% NaCl diet for 4 weeks. In acute experiments, manidipine, a calcium ...
Schleiffer R - - 1995
Calcium intake has been implicated as being an important factor in the development and treatment of hypertension. The mechanisms underlying the relationship between calcium and blood pressure are not yet clearly defined. Experimental studies have documented an inverse association between calcium intake and blood pressure level. For 15 years it ...
Frei M R - - 1995
The objective of this study was to determine the thermal distribution and concomitant cardiovascular changes produced by whole-body exposure of ketamine-anesthetized rats to radiofrequency radiation of millimeter wave (MMW) length. Rats (n = 13) were implanted with a flow probe on the superior mesenteric artery and with a catheter in ...
Shaw L M - - 1995
OBJECTIVE: To investigate whether, when angiotensin converting enzyme inhibitors are administered to young, genetically hypertension-prone animals, the demonstrated attenuation of blood pressure development and prevention of the structural changes usually observed in small arteries is attributable to the prevention of angiotensin II production. DESIGN: We have treated spontaneously hypertensive rats ...
Chevalier B - - 1995
BACKGROUND: Although severe arrhythmias are still a major problem in patients with left ventricular hypertrophy (LVH), the relationship between ventricular remodeling and its regression or prevention, and the prevalence of ventricular premature beats (VPB) or more sustained arrhythmias are still poorly explored in hypertensive heart disease. METHODS AND RESULTS: Holter ...
Suzuki S - - 1995
We report in the present study the effect of intrathecal treatment with antisense oligonucleotides complementary to thyrotropin releasing hormone (TRH) receptor mRNA on the pressor response to intrathecal administration of TRH and on resting arterial blood pressure in Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). In 16-week-old male WKY ...
Wang X - - 1995
Autoregulation of total and zonal glomerular filtration rate (GFR) in outer, middle and inner cortex was estimated in spontaneously hypertensive rats (SHR), from the tubular uptake of 125I-labeled aprotinin (125I-Ap), injected at control renal arterial pressure (RAP), and 131I-Ap, injected at reduced RAP in left kidney. Normotensive Wistar-Kyoto (WKY) rats ...
Zimlichman R - - 1995
To investigate the effect of hyperinsulinemia on arteriolar hypertrophy, myocardial hypertrophy, and blood pressure, we administered insulin intraperitoneally to SHR and WKY rats for 3 consecutive weeks. To prevent hypoglycemia, the drinking water contained 10% sugar, and to accentuate the blood pressure, their chow contained 8% table salt. Blood pressure ...
Davidson A O - - 1995
We used a cross between the stroke-prone spontaneously hypertensive rat (SHRSP) strain and the Wistar-Kyoto (WKY) normotensive strain to elucidate the genetic basis of hypertension. Previous studies have reported conflicting evidence for the contribution of the Y chromosome to hypertension in these models. To investigate further the role of the ...
Panizo A - - 1995
In genetic and acquired hypertension, a structural remodeling of the nonmyocyte compartment of myocardium, including the accumulation of fibrillar collagen and other components of the extracellular matrix (ECM) within the interstitium, represents a determinant of pathologic hypertrophy that leads to ventricular dysfunction. Therefore, to evaluate the potential benefit of the ...
Lacolley P - - 1995
1. The contribution of vasomotor tone to the increased stiffness of carotid arteries in living spontaneously hypertensive rats (SHR) is largely unknown. Whether a reduced vascular tone is associated with an increase or a decrease in arterial stiffness in vivo remains to be determined. The goal of the present investigation ...
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