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van Gorp A W - - 1995
The distensibility of the arterial system, which is partly determined by arterial wall structure, smooth muscle tone, and actual pressure level, decreases with aging and hypertension. Our aim was to compare aortic wall properties in 3- and 6-month-old normotensive Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) at comparable blood ...
Schussheim A E - - 1995
Intracellular pH (pHi) and developed pressure during hypercapnic acidosis were studied in the spontaneously hypertensive rat (SHR) heart and Wistar-Kyoto controls. Developed pressure was determined using a modified Langendorff isovolumic perfusion technique and 31P magnetic resonance spectroscopy was used to determine pHi. In response to acidosis, both developed pressure and ...
Schiffrin E L - - 1995
1. Endothelin-1 gene expression is enhanced in aorta and mesenteric arteries, and possibly other vessels, of deoxycorticosterone acetate (DOCA)-salt hypertensive rats but is normal or reduced in spontaneously hypertensive rats (SHR). Bosentan, a mixed ETA/ETB endothelin receptor antagonist, blunts the development of elevated blood pressure of DOCA-salt hypertensive rats but ...
Calhoun D A - - 1995
We recently reported that high dietary NaCl exposure significantly increases both daytime and nighttime mean arterial pressure in male spontaneously hypertensive rats (SHR) but only nighttime values in male normotensive Wistar-Kyoto rats (WKY). In the present study we used a telemetry monitoring system to evaluate the effects of high dietary ...
Smid S D - - 1995
Treatment of spontaneously hypertensive rats (SHR) with alpha-adrenoceptor antagonists failed to alter the development of hypertension in this animal model. However, agents such as captopril (CAP) and losartan (LOS) which interfere with the renin-angiotensin system effectively prevented the development of hypertension. When tolerance occurred in the presence of doxazosin (DOX) ...
Rozsa Z - - 1995
We examined the possibility that changes of the mesenteric resistance play a role in the development of hypertension in spontaneously hypertensive rats (SHRs). Genetically hypertensive (Okamoto) and normotensive Wistar rats (WKYs) were studied after oral treatment for 6 weeks with 100 mg of captopril dissolved in 500 ml water daily. ...
Lichtenstein O - - 1995
Hypertension is known to decrease arterial distensibility and volumetric compliance, as reported from pressure-volume experiments and ring and strip studies of human and animal large arteries. However, recent data using noninvasive in vivo recording of vessel diameter suggest that the cross-sectional compliance of large arteries can be unchanged or even ...
Xiao J - - 1995
Hypertensive individuals often exhibit immune abnormalities. We have previously reported that spontaneously hypertensive rats (SHR) had a severely depressed lymphocyte proliferation response caused by excessive nitric oxide (NO) from macrophages and vascular smooth muscle cells (VSMC). However, the development of hypertension was not correlated with the lymphocyte depression and elevated ...
Traub O - - 1995
Recent studies have shown that angiotensin converting enzyme (ACE) inhibitor treatment in young spontaneously hypertensive rats (SHR) reduces blood pressure into adulthood. This study explored changes in vascular reactivity in adult normotensive (WKY) rats and stroke-prone SHR (SHRSP) receiving the following treatments at 6-10 weeks of age: (a) ACE inhibitor ...
Qiu H Y - - 1995
An in situ model was developed for studying mechanical properties of mesenteric arteries in rats. A branch of the mesenteric artery was exposed and dissected in normotensive (WKY) and spontaneously hypertensive rats (SHR). A catheter was introduced into the larger branch of the mesenteric artery and connected to a pressure ...
Vacher E - - 1995
OBJECTIVE: To investigate the haemodynamic and morphological effects resulting from the chronic administration to young spontaneously hypertensive rats (SHR) of a new selective angiotensin II subtype 1 (AT1) receptor antagonist, SR 47436/BMS-186295 (SR/BMS) both during and after the treatment period. METHODS: SR/BMS (60 mg/kg per day, orally) or distilled water ...
Samani N J - - 1995
The SA gene was initially identified by differential hybridisation because of its higher expression in the kidney of the spontaneously hypertensive rat (SHR) compared with the normotensive Wistar-Kyoto rat. In subsequent studies, the allele of the SA gene from the SHR and several other genetically hypertensive strains was found to ...
Madeddu P - - 1995
1. We determined whether early inhibition of angiotensin II subtype1 (AT1) receptors by the newly synthesized nonpeptidic antagonist, A-81988, can attenuate the development of hypertension in spontaneously hypertensive rats (SHR) and if the altered blood pressure phenotype can be passed on to the subsequent generation, not exposed to the antagonist. ...
Lodwick D - - 1995
Allelic variants at the human angiotensinogen locus have recently been reported to increase susceptibility to the development of essential hypertension. In this study we analyzed the role played by angiotensinogen in the elevated blood pressure of the spontaneously hypertensive rat (SHR). The SHR angiotensinogen locus (on chromosome 19) cosegregated with ...
Vulpis V - - 1995
The aim of this study is to investigate the effects of two ACE-inhibitors with different chemical formulae, cilazapril (CLZ) and captopril (CPT), on left ventricular myocardiocytes from spontaneously hypertensive rats (SHR), characterized by ultrastructural alterations associated with left ventricular hypertrophy, and from Wistar-Kyoto (WKY) rats, considered as controls. After CLZ-treatment, ...
Stasch J P - - 1995
The cardiovascular consequences of inhibition of the neutral endopeptidase 24.11 (NEP) with the orally active NEP inhibitor sinorphan were evaluated by determining long-term effects of the drug on hemodynamic, hormonal and structural parameters in stroke-prone spontaneously hypertensive rats (SHR-SP). Systolic blood pressure increased in young SHR-SP from 194 +/- 2 ...
Hayashi K - - 1995
Renal autoregulation curves are reset toward higher renal arterial pressure in spontaneously hypertensive rats (SHR) compared with those in Wistar-Kyoto rats (WKY). We previously demonstrated that myogenic afferent arteriolar constriction is shifted to higher renal arterial pressure. To investigate whether nitric oxide participates in the regulation of myogenic tone, we ...
Larson T S - - 1995
An increase in medullary blood flow has been implicated as a mediator of the natriuresis following increases in renal perfusion pressure (RPP). We examined whether administration of L-arginine, the substrate for nitric oxide production, restores the impaired vasa recta hemodynamic response to increases in RPP and the blunted pressure natriuresis ...
Korner P I - - 1995
We studied the long-term effects after withdrawal of enalapril, an angiotensin-converting enzyme inhibitor, on tail systolic pressure and cardiovascular structural properties in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). Observations in control rats were from 4 to 35 weeks of age, whereas treated rats received enalapril from 4 to ...
Douglas S A - - 1995
Indirect evidence has implicated endothelin-1 in the pathogenesis of hypertension. In the present study we examined such a role directly with SB 209670, a novel nonpeptide endothelin receptor antagonist. The antihypertensive and hemodynamic effects of SB 209670 were examined in conscious, unrestrained spontaneously hypertensive (SHR), normotensive Wistar-Kyoto (WKY), and renin-hypertensive ...
Tsoucaris D D Department of Internal Medecine, Broussais Hospital, Paris, - - 1995
In a previous study (J Hypertens 1993, 11:135-139) our group showed that in anaesthetized rats, although pulse pressure increased from the proximal (common carotid artery) to the distal (terminal aorta) portion of the aorta in normotensive Wistar-Kyoto (WKY) rats, such a pulse pressure gradient was not observed in spontaneously hypertensive ...
Johnson R A - - 1995
Heme oxygenase is a mammalian enzyme that converts heme to biliverdin and carbon monoxide. Carbon monoxide activates soluble guanylate cyclase and relaxes vascular smooth muscle, and it has been implicated as a potential neuromessenger. The regulatory functions of endogenous carbon monoxide on hemodynamics are not known. Zinc deuteroporphyrin 2,4-bis glycol ...
Iida N - - 1995
The aims of this study were to elucidate the vasoconstrictor mechanism that mediates the changes in celiac and mesenteric vascular resistances during vasoconstriction and hypertension induced by ganglionic blockade and to explore the preferential mechanism that contributes to the elevation of arterial pressure in conscious spontaneously hypertensive rats (SHR). In ...
O'Sullivan J B - - 1995
Brief angiotensin-converting enzyme (ACE) inhibition in young spontaneously hypertensive rats (SHR) causes a persistent reduction in blood pressure. Bradykinin accumulation may contribute to these long-term effects, and to test this hypothesis we studied the consequences of bradykinin B2 receptor antagonism during ACE inhibitor treatment in young SHR. Male SHR were ...
Vacher E - - 1995
The aim of this study was to determine whether activation of vasopressin (AVP) peripheral V1 receptors is involved in the development of malignant hypertension, stroke, and end-organ damage in stroke-prone spontaneously hypertensive rats (SHR-SPs). For this purpose, young salt-loaded SHR-SPs were treated orally daily from their 5th to 34th week ...
Amann K - - 1995
Hearts of stroke-prone spontaneously hypertensive rats (SHR) were investigated by means of stereology and were compared with those of normotensive. Wistar-Kyoto controls. At the age of 9 months, hypertensive rats showed cardiac hypertrophy, marked myocardial fibrosis, activation of nonvascular interstitium, focal myocytial degeneration, reduction of capillarization, and microarteriopathy of small ...
Takahashi S - - 1995
An elevation of blood pressure is observed in approximately 30% of dialysis patients treated with recombinant human erythropoietin (rHuEPO). Various studies have been performed in order to elucidate possible underlying mechanisms, but it is not yet well understood whether there is one major mechanism involved. In this present study, samples ...
Korner P I - - 1995
In chronic hypertension, vascular resistance is raised and there is concentric left ventricular (LV) hypertrophy, at least in animal models. Together these changes enhance hemodynamic performance ("amplifier" properties) and help maintain elevated blood pressure (BP) and net microcirculatory exchange. Sometimes there is vascular "remodelling", with only luminal narrowing, but no ...
Barlow R J - - 1995
Six patients with delayed pressure urticaria (DPU) applied clobetasol propionate (0.05%) ointment or its base to predetermined test sites on the right and left thigh as part of a randomized, double-blind study. A pressure challenge was administered to each test site at the initial visit and repeated after 3 days ...
Stasch J P - - 1995
The cardiovascular consequences of endothelin (ET) blockade with the ETA receptor antagonist FR 139317 were evaluated by determining long-term effects of the drug on hemodynamic, hormonal, 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 lesions. ...
Chiu E K - - 1995
The role of sympathetic function in the mechanism of the decrease in arterial pressure that follows withdrawal of an intravenous infusion of arginine vasopressin (AVP) in spontaneously hypertensive rats (SHR) was studied by comparing this withdrawal-induced antihypertensive phenomenon (WAP) in rats with intact sympathetic function to those subjected to sympathectomy. ...
Bing O H - - 1995
Studies of hemodynamics and intrinsic left ventricular myocardial function are carried out to investigate the transition from stable hypertrophy to cardiac decompensation in the aging (18-24 months) spontaneously hypertensive rat (SHR). Echocardiographic data in awake animals demonstrate increased end-diastolic and end-systolic volumes and depressed ejection fractions in left ventricles from ...
Watts S W - - 1994
We have tested the hypothesis that altered vascular reactivity, specifically the appearance of spontaneous and BayK 8644 (L-type voltage gated calcium channel agonist)-induced oscillations in the carotid artery and the sarcoplasmic reticulum Ca(2+)-ATPase inhibitor cyclopiazonic acid (CPA)-induced oscillations in the aorta from stroke-prone spontaneously hypertensive rats (SHRS), are dependent upon ...
Takeda N - - 1994
OBJECTIVE: To investigate the effects of long term treatment with delapril hydrochloride (an angiotensin-converting enzyme inhibitor) on myocardial contractility and ventricular myosin isoenzymes in spontaneously hypertensive rats (SHR). DESIGN: Delapril hydrochloride (10 mg/kg/day by mouth) was administered to 22- to 24-week-old male SHR for eight to 10 weeks. The isometric ...
Packer C S - - 1994
Heart disease, stroke, and kidney failure are leading causes of death. Essential hypertension is the major predisposing risk factor of cardiovascular disease. Yet, after several decades of intensive investigation, the initiating causative mechanism of essential hypertension is still unknown. However, investigators in the field generally agree that an increased total ...
Jin X Q - - 1994
Captopril (Cap) 20 mg.kg-1.d-1 and clonidine (Clo) 300 micrograms.kg-1.d-1 were given po to SHR from their parents mating day to 24 wk of age, with untreated, age-matched SHR and WKY as controls. Stress cardiac function was assessed by the development of LVdp/dtmax in response to incremental pressure load (phenylephrine, Phe) ...
Hüsken B C - - 1994
We have studied the effects of hypertension and aging on the concentration-response curves for alpha 1-adrenoceptor-mediated vasoconstriction and methacholine-induced endothelium-dependent relaxation. The experiments were performed in aortic rings and in perfused mesenteric vascular bed preparations taken from WKY rats, from SHR of 16-18, 28-30, and 58-60 weeks, and from 16- ...
Heimann A - - 1994
Hypobaric hypotension was used to reduce systemic blood pressure in rats below the lower threshold of CBF autoregulation to evaluate a new laser Doppler (LD) "scanning" technique. Spontaneously breathing male Wistar Kyoto rats (n = 8) were anesthetized with chloral hydrate and the head fixed in a stereotaxic head holder. ...
Christe M E - - 1994
The purpose of this study was to characterize the effect of chronic treatment with an angiotensin-converting enzyme (ACE) inhibitor on left ventricular function in spontaneously hypertensive rats (SHR). Cilazapril (5 mg/kg) was administered in the drinking water continuously for 11 wk, beginning at 4 wk of age. Systolic arterial pressure ...
Lee R M - - 1994
BACKGROUND: Among the antihypertensive agents available for the treatment of hypertension, only angiotensin-converting enzyme (ACE) inhibitors have been shown to modify cardiovascular changes in structure and function. OBJECTIVE: To study the effect of perindopril treatment on hypertension and stroke prevention in two genetic models of hypertensive rats. DESIGN: Adult (15 ...
Verma S - - 1994
To determine the relationship between hyperinsulinemia and hypertension in spontaneously hypertensive rats (SHR), the antihyperglycemic agent metformin was administered to SHR and their Wistar-Kyoto (WKY) controls, and its effects on plasma insulin levels and blood pressure were examined. Five-week-old rats were started on oral metformin treatment (350 mg.kg-1.day-1, which was ...
Basu A K - - 1994
Evidence to support a hypertensinogenic role of family 3A cytochrome P-450 (CYP3A) activity is that troleandomycin, a selective inhibitor of CYP3A, decreases both blood pressure and in vivo corticosterone 6 beta-hydroxylation in spontaneously hypertensive rats (SHR). Renal CYP3A activity is markedly increased in SHR compared with Wistar-Kyoto (WKY) rats. Cyclosporine ...
Head G A - - 1994
1. The role of cardiac reflexes in baroreflex control mechanisms and the changes that occur in chronic hypertension is reviewed. The rapid resetting properties of the arterial baroreceptors ensures its role in short-term rather than long-term control of blood pressure. 2. In hypertensive humans and animals, the baroreceptor-heart rate reflex ...
Wada K - - 1994
The antihypertensive effect of (+/-)-3-(4-allyl-1-piperazinyl)-2,2-dimethylpropyl methyl 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylate dihydrochloride (NKY-722, CAS 117241-46-0) was examined in conscious spontaneously hypertensive rats (SHR), normotensive Wistar rats (NWR) and anesthetized NWR, and its vasodilatory effect was investigated in the perfused NWR mesenteric vascular bed. NKY-722 and nicardipine administered intravenously (10-100 micrograms/kg) and orally (0.3-10 mg/kg) ...
Hu C T - - 1994
In hypertensive animals and humans, cardiac hypertrophy may occur as a consequence of an external load on the heart. Several studies have suggested that the non-pulsatile components of arterial haemodynamics, such as arterial pressure and vascular resistance, do not adequately represent the ventricular afterload and are not well correlated with ...
Privette T H - - 1994
Dentate granule cells can be selectively destroyed by intrahippocampal injections of colchicine. This study evaluates the consequences of granule cell destruction on blood pressure regulation in the normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rat (SHR). Bilateral destruction of dentate granule cells at 6 weeks of age produced a significant increase ...
Brooks W W - - 1994
We studied functional and intracellular calcium responses to treppe and extracellular calcium in spontaneously hypertensive rat (SHR) hearts during the transition from compensated pressure overload to failure. Intracellular calcium was measured using aequorin, a bioluminescent Ca2+ indicator. Experiments were performed with intact, isovolumically contracting, buffer-perfused hearts from three rat groups: ...
Jenkins C - - 1994
The objective of this study was to determine the effect of a high sodium diet and prepubertal castration (5-6 weeks) and androgen replacement therapy on blood pressure in male normotensive, borderline hypertensive and hypertensive rats on a high sodium diet between 9-22 weeks of age. The strains used were: Wistar ...
Dohi Y - - 1994
Endothelial regulation of peripheral vascular resistance is impaired in hypertension. We studied the effects of different antihypertensive therapies on endothelial function in perfused mesenteric resistance arteries. Spontaneously hypertensive rats (SHR) aged 7 weeks were treated with either the nonpeptidic angiotensin II (AII) receptor antagonist CGP 48369, the angiotensin-converting enzyme (ACE) ...
Danysz A - - 1994
Administration of coenzyme Q-10 (10 mg/kg) once a day for 4 weeks decreased the arterial blood pressure in SHR's. Enalapril and nitrendipine administered in a single dose caused significant decrease of blood pressure. Application of enalapril and nitrendipine to rats chronically pretreated with coenzyme Q-10 revealed, that the maximal hypotensive ...
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