Search Results
Results 301 - 350 of 1260
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Takewa Y - - 1997
The effects of reduced pulmonary arterial blood flow (PAF) during venoarterial bypass (VAB) on hemodynamic and humoral conditions were investigated in a series of experiments in a chronic animal model. A biventricular bypass system was installed in five adult goats weighing 49.8 +/- 1.1 kg. Two weeks later, the extracorporeal ...
Flesch M - - 1997
BACKGROUND: Hypertensive cardiomyopathy is a major risk factor for the development of chronic heart failure. OBJECTIVE: To investigate whether treatment with an angiotensin converting enzyme inhibitor (ACEI) or with an angiotensin type 1 receptor antagonist (AT1-RA) is sufficient to prevent the development of hypertensive cardiomyopathy and cardiac contractile dysfunction. Special ...
Martín I - - 1997
The aim of the present study was to provide an overview of the role of circulating gonadal steroids on the adaptive changes of the renin-angiotensin system to chronic hypobaric hypoxia (CHH: 4400 m simulated altitude in an hypobaric chamber) and the development of experimental hypertension by bilateral renal ischemia. In ...
Nafz B - - 1997
In Goldblatt hypertension, renal artery stenosis reduces renal arterial pressure (RAP) and renal blood flow (RBF) and thereby increases plasma renin activity (PRA) levels. Although it is clear that reduction in RAP stimulates renin, the decrease in RBF may contribute to higher PRA as well. However, it has hitherto never ...
DiPaola N R - - 1997
When an approximately 30 centiMorgan (cM) region of chromosome 13 containing the renin gene from the Dahl salt-resistant rat (R) was introgressed into the Dahl salt-sensitive rat (S), the resulting congenic rat (designated S.R-Ren) had a systolic blood pressure on a 2% (w/w) salt diet that was 24 mmHg lower ...
Bertaux F - - 1997
Renin is an aspartyl protease that is involved in the conversion of angiotensinogen to angitensin II and hence participates in the regulation of blood pressure. Mice are polymorphic for the number of renin genes with some strains harbouring two renin genes, Ren-1d and Ren-2. To study the role of renin ...
Bakris G - - 1997
BACKGROUND: Arginine vasopressin (AVP), in addition to being an antidiuretic hormone, might also have pressor effects relevant to the maintenance of hypertension. Results from several experimental and clinical studies suggested that the pressor function of AVP is more important in low-renin hypertension and in the salt-loaded state and that it ...
Chiu N - - 1997
OBJECTIVE: There is evidence that kinins contribute to some of the renal, cardiovascular, and endocrine effects of the diuretic furosemide. The aim of the present study was to investigate the role of kinins in the regulation of renin secretion, blood pressure, and heart rate under resting conditions and after administration ...
Jensen J - - 1997
OBJECTIVE: To determine plasma renin activity (PRA), angiotensin I (Ang I), and aldosterone (ALDO) values in clinically normal cats and hypertensive cats with renal disease, and the relation of renin-angiotensin-aldosterone activation in response to treatment with beta-blockers or angiotensin-converting enzyme inhibitors. ANIMALS: 5 normotensive healthy control cats and 12 Untreated ...
Trevisani F - - 1997
BACKGROUND/AIMS: Measurements of plasma endothelin-1 and -3 in pre-ascitic cirrhosis have provided controversial results. Similarly, the role of the endothelin system in the pathogenesis of volume and hemodynamic disturbances of cirrhosis is still debated. To provide a further insight into this issue, we assessed the daily fluctuations of plasma endothelins ...
Bohlender J - - 1997
We examined the effect of chronic human renin infusion and human renin inhibition on blood pressure in a unique transgenic rat model. We infused incremental doses of human renin (1 to 500 ng/h) with minipumps for 10 days into rats harboring the human angiotensinogen gene [TGR (hAOGEN)1623]. We measured blood ...
Fukamizu A - - 1997
Much of our knowledge about blood pressure regulation has come from a huge number of biochemical, endocrinologic, pharmacologic, clinical, and physiologic studies. The renin-angiotensin system, composed of enzymatic and signal-transduction cascades, has a key role in regulating arterial blood pressure and in developing certain forms of experimentally induced hypertension and ...
Zimmerman B G - - 1997
A microdissected rabbit intrarenal arterial network (IAN) perfused at constant flow with Krebs-bicarbonate solution was employed to determine whether this network, which has a high renin content, releases angiotensin II (AII) either spontaneously or during beta-adrenergic stimulation. Six groups of experiments were conducted in which samples of the vascular effluent ...
Pecins-Thompson M - - 1997
Gonadal steroids have been implicated in the control of blood pressure and fluid homeostasis. These experiments test the effect of progesterone in ovariectomized ewes on blood pressure, volume, and hormone responses to hypotension. Eight ewes were each studied in four conditions: ovariectomized, progesterone and estrogen replaced, progesterone replaced, or sham ...
Sasaguri M - - 1997
OBJECTIVE: Recent clinical studies suggest that the reflex increase in sympathetic nervous activity accompanying a reduction in blood pressure may contribute to the untoward effects of dihydropyridine calcium antagonists. The aim of this study was to examine whether plasma noradrenaline levels and renin activity are increased with the reduction of ...
Meeran K - - 1997
Adrenomedullin has been proposed to be a circulating hormone regulating systemic and pulmonary blood pressure. A potential therapeutic role in the management of pulmonary hypertension has been suggested based on animal studies, but the pharmacokinetics and pharmacodynamics in human subjects have not been studied. We have infused adrenomedullin into volunteers ...
Isnard R - - 1997
In a double-blind, placebo-controlled study, the central and peripheral hemodynamic effects of 100 mg oral flosequinan and the impact of this drug on neurohormonal activation were noninvasively evaluated in 18 patients with congestive heart failure, after the first administration and after 10 days of treatment. No significant hemodynamic and neurohormonal ...
Zimmerman B G - - 1997
In this review, we present background material that provides partial support for a tissue renin-angiotensin system (RAS). Evidence for the existence of this system relied in part on the use of drugs, which has entailed using low doses or concentrations of angiotensin-converting enzyme inhibitors, renin inhibitors, and angiotensin antagonists to ...
Ciana G - - 1997
A premature baby had severe hypertension associated with idiopathic arterial calcification of infancy. Despite the fact that there was laboratory evidence of renin-mediated hypertension, the disease was refractory to specific renin antagonist and failed to respond to conventional medical treatment. Prostaglandin E1 (PGE1) infusion (dosage range 0.017-0.068 microgram/kg/min) promptly controlled ...
Fedorova O V - - 1996
Previous studies with micropigs showed that conditioned suppression of respiration preceding the onset of an avoidance task was associated with increased pCO2, decreased plasma pH, decreased hematocrit, and increased blood pressure with no change in heart rate. Voluntary hypoventilation by humans, which evoked similar effects, was found to elicit increases ...
Knoblich P R - - 1996
We evaluated pressure-dependent stimulation of renin release in rats with sustained hypertension induced by chronic blockade of nitric oxide synthase with N omega-nitro-L-arginine methyl ester (L-NAME) for 5 to 7 days. Rats were anesthetized and catheters were inserted into the carotid artery and abdominal aorta for measurement of arterial pressures. ...
Danser A H - - 1996
The beneficial effects of angiotensin converting enzyme (ACE) inhibitors in heart failure appear to be independent, at least in part, of their effect on blood pressure. The existence of a local cardiac renin angiotensin system is often suggested as an explanation. It has been known for some time that a ...
Fogo A - - 1996
Effectiveness of antihypertensive agents is assessed not only by systemic blood pressure levels, but by multiple parameters that reflect specific organ functions. Among antihypertensive agents, those which inhibit angiotensin actions show particular efficacy in ameliorating end organ damage. This efficacy likely reflects the central role that angiotensin has in regulating ...
Lippoldt A - - 1996
The transgenic rat (TGR) (mRen-2)27 is said to have low circulating active renin values in plasma and little or no renin gene expression in the kidney. Nevertheless, intrarenal angiotensin II-related effects appear to be responsible for the rightward shift in pressure-natriuresis curves of TGR. To clarify the role of the ...
Courneya C A - - 1996
It is not known how the intrarenal mechanisms that control renin release, in particular the intrarenal receptor, respond to the structural changes in renal vasculature that are secondary to hypertension. It is also not known whether baroreflex control of renin release is affected by hypertension. We hypothesized impairment at both ...
Bijlstra P J - - 1996
OBJECTIVE: To investigate methods to diagnose renal artery stenosis (RAS) among the general hypertensive population. METHODS: We studied the value of clinical and biochemical characteristics at the outpatient clinic to identify subjects with a renal artery narrowing of more than 50% of the luminal surface among 1047 hypertensive patients. Included ...
Vallès Prats M - - 1996
The effects of inhibition of the renin-angiotensin system with quinapril on adrenergic transmission were determined in 18 patients with moderate essential hypertension. Plasmatic renin activity, catecolamines, and aldosterone as well as vascular reactivity after norepinephrine and angiotensin II perfusion were determined before and after treatment with the ACE inhibitor quinapril ...
Lin C - - 1996
The renin-angiotensin system (RAS) is a major contributor in the regulation of blood pressure, and pharmacologic manipulation of this system has resulted in a beneficial class of therapeutic agents, which include angiotensin-converting enzyme (ACE) inhibitors. However, ACE inhibitors are not specific for RAS, and in addition, they can affect bradykinin ...
Bloomfield E L - - 1996
Craniotomy for resection of cerebral arterial venous malformation has been associated with postoperative hypertension, which necessitates administration of large doses of antihypertensive medications to control blood pressure. Controlling blood pressure is essential because hypertensive episodes can lead to postoperative cerebral hemorrhage with increases in morbidity and mortality. We measured vasoactive ...
Goonasekera C D - - 1996
BACKGROUND: Beginning in 1978 a cohort of patients with reflux nephropathy first seen at a London Childrens hospital have had 5-yearly follow-ups. This is the fourth (15-year) report from that series. METHODS: Of the original 100 normotensive children with reflux nephropathy 78 were traced for the 15-year study in 1994. ...
Lewanczuk R Z - - 1996
Parathyroid hypertensive factor (PHF) is a circulating hypertensive factor, levels of which are inversely related to renin profile. Given this relationship, it was hypothesized that a PHF level might serve as an alternate predictor of antihypertensive efficacy in hypertensive patients, avoiding the difficulties associated with renin profiling. To test this ...
Yuasa S - - 1996
Dietary Ca is an important modulator of blood pressure in humans and rats. Since the kidney plays a key role in the pathogenesis of hypertension, the effects of a low Ca diet (0.01% Ca) on blood pressure and pressure natriuresis response were studied in normotensive Sprague-Dawley rats. In addition, a ...
Blair M L - - 1996
1. The paraventricular hypothalamic nucleus (PVH) is a complex structure with both neuroendocrine and autonomic functions. It is a major source of vasopressin and the primary source of corticotropin-releasing factor. In addition, parvicellular PVH neurons have reciprocal connections with brainstem autonomic centres and directly innervate sympathetic preganglionic neurons. Evidence is ...
Strohmaier W L - - 1996
PURPOSE: There is ongoing controversy regarding blood pressure changes after extracorporeal shock wave lithotripsy (ESWL*). Experimental data suggest a role for renin but only few data are relevant to humans. It has been shown that renin secretion is stimulated by endothelin, a recently discovered peptide with strong vasoconstrictive properties and ...
Pinto Y M - - 1996
In this paper, we review the hypothesis that activated tissue renin-angiotensin systems play a detrimental role in heart failure. The main arguments for this idea are discussed: a) tissue renin-angiotensin systems behave functionally distinct from the circulating renin-angiotensin system; b) tissue renin-angiotensin systems are activated in heart failure; c) activated ...
Braun C - - 1996
The Han:SPRD (PKD) rat is a new animal model of autosomal dominant polycystic kidney disease (ADPKD) which resembles many clinical and pathoanatomical features of human ADPKD. The aim of the present study was to analyse age-dependent changes in renal haemodynamics and renal renin secretion which could be of pathophysiological importance ...
Bellissant E - - 1996
The effects of a single oral dose (6 mg) of the angiotensin-I converting enzyme inhibitor, spirapril, on systemic, pulmonary and regional (brachial, renal, hepato-splanchnic) hemodynamics as well as on biological parameters investigating the renin-angiotensin-aldosterone and sympathetic nervous systems were studied over a 24-hour period in eight patients with severe congestive ...
Tauchi K - - 1996
We examined the involvement of the renin-angiotensin system in the maintenance of hypertension of the rat with congenital hydronephrosis having no urinary tract obstruction. The congenital hydronephrosis rat (HNR) had a significantly higher systolic blood pressure (181 +/- 9.5 mm Hg in the male bilateral hydronephrosis rat, BHN, at 13 ...
Gutmann J L - - 1996
The effects of varying clinically relevant patterns of anaesthetic-vasoconstrictor combinations used for periradicular surgery on plasma concentrations of catecholamines and haemodynamic responses was studied in the canine model. Five mongrel dogs were anaesthetized with sodium pentobarbitol. A femoral cannula was inserted to measure central blood pressure and an ECG was ...
Kleinert H D - - 1995
Modification of the renin-angiotensin-aldosterone system by renin inhibitors may be an alternative to angiotensin-converting enzyme inhibitors in the treatment of cardiovascular disease. The development of clinically useful renin inhibitors has been hampered by a variety of pharmacologic problems, most notably the poor oral bioavailability of these peptide-related compounds. Peptidomimetic renin ...
Rossi G - - 1995
BACKGROUND: Arterial hypertension is the leading cause of cardiovascular disease and is associated with an increased risk of stroke and heart attack. These complications have been largely attributed to the remodeling of the arterial wall, including accelerated atherosclerosis occurring in hypertensive patients. Although the risk of haemorrhagic stroke seems to ...
Takeda R - - 1995
Referring to the mosaic theory of Page, the authors present an overview of recent topics related to the participation of endocrine and auto-paracrine factors, such as steroids, ouabain-like substance, insulin, renin-angiotensin and endothelin, in the pathogenesis of primary hypertension. These factors promote the development of hypertension in either a direct ...
Böhm M M Max-Delbrück-Center for Molecular Medicine (MDC), Berlin-Buch, - - 1995
To study the effect of angiotensin II receptor AT1 blockade on blood pressure, gene expression and pathomorphology of transgenic rats harbouring the mouse Ren-2 gene [TGR(mREN2)27], that develop fulminant hypertension while exhibiting suppressed components of the circulating renin-angiotensin system. TGR(mREN2)27 were treated orally with the newly developed AT1-specific angiotensin receptor ...
Rongen G A - - 1995
The successful introduction of angiotensin converting enzyme (ACE) inhibitors in the treatment of patients with essential hypertension or heart failure has increased interest in the (patho)physiological role of the renin-angiotensin system (RAS). ACE is not only involved in the formation of angiotensin II from angiotensin I, but also inactivates vasoactive ...
Beierwaltes W H - - 1995
The macula densa is a regulatory site for renin. It contains exclusively the neuronal isoform of nitric oxide synthase (NOS), suggesting NO could stimulate renin secretion through the macula densa pathway. To test whether neuronal NOS mediates renin secretion, renin was stimulated by either the renal baroreceptor or the diuretic ...
Sealey J E - - 1995
This report investigates whether there is evidence that prorenin has cardiovascular effects. The report concludes that prorenin may indeed have cardiovascular effects, causing regional vasodilation by counteracting the vasoconstrictor effect of renin, and thereby maintaining blood flow to vital organs. This view is based on several observations. In direct contrast ...
Marfella R - - 1995
The present study aimed at evaluating whether acute elevations of plasma glucose concentrations could influence systemic hemodynamic parameters and baroreflex activity in humans. Plasma glucose concentrations were acutely raised to 15 mmol/l in 12 healthy male volunteers. During hyperglycemia, there were significant increments of systolic [from 118 +/- 9 to ...
Rudy David R. - - 1995
This double-blind experiment tested the hypothesis that renin is a mediator of neurogenic hypertension. Forty-three of 46 hypertensive (mean BP 142/94) were typed for renin index and treated by combinations of group therapy (n = 32) or placebo (n = 11). A treatment effect in the therapy group resided virtually ...
Jurklies B - - 1995
Morphology studies imply a possible contribution of the renin-angiotensin system (RAS) to neurotransmission in the mammalian retina. To investigate further the functional role of the RAS in the visual system of humans, we tested the effects of the angiotensin-converting enzyme (ACE) inhibitor Captopril (Capt; 25 mg) on electroretinogram (ERG) recordings, ...
Chiu T - - 1995
Nitric oxide plays an important role in the regulation of arterial pressure by its actions to dilate vascular smooth muscle, alter sympathetic neural activity, and modulate the vasoconstrictor action of norepinephrine, angiotensin II and vasopressin. Nitric oxide may also influence blood pressure regulation by altering the secretion of renin and ...
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