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Results 351 - 400 of 1261
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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 ...
Bernardi M - - 1995
Little is known about the effect of posture on the circulatory abnormalities of advanced cirrhosis. We evaluated the systemic hemodynamics, measured by Doppler-echocardiography, atrial natriuretic factor, plasma renin activity and plasma norepinephrine, in 10 patients with cirrhosis and ascites and 10 healthy controls, after 2 h of standing and during ...
Aliaga L - - 1995
We studied the interrelationships between systemic hemodynamics, sodium excretion and the renin-angiotensin system in 28 nonazotemic cirrhotic patients on a sodium restricted diet. Renal hemodynamics were also assessed. The patients were divided into three groups. Group A comprised 9 patients without ascites or edema; group B comprised 8 patients with ...
Heropoulos M - - 1995
This study was designed to evaluate effects of enalaprilat, an angiotensin-converting enzyme inhibitor, on hemodynamic and hormonal responses during surgery at endotracheal intubation, incision, and limb-tourniquet inflation. Thirty patients undergoing limb procedures with general anesthesia (N2O/narcotic technique) and a pneumatic tourniquet were randomized to receive either preoperative enalaprilat (1.25 mg ...
Cockcroft J R - - 1995
The renin-angiotensin system is intimately involved in the control of sodium and water balance, the activity of the sympathetic nervous system, mitogenesis and the regulation of vascular tone. There is evidence that many of these effects may be controlled at a local level by independent tissue renin-angiotensin systems. Drugs that ...
Kotamäki M - - 1995
The effects of smoking on autonomic function, the renin-angiotensin-aldosterone system, plasma catecholamine and 11-dehydro-thromboxane B2 values were studied in 37 young male military pilot candidates, 19 smokers and 18 non-smokers. There was a higher diastolic blood pressure at rest and higher systolic blood pressure after 5 min during the orthostatic ...
Stock P - - 1995
In its classical definition, the renin-angiotensin system (RAS) acts predominantly by endocrine mechanisms. This view has been modified since several components of the RAS and their mRNAs were found in peripheral tissues. These findings gave rise to the concept of local tissue renin-angiotensin systems. Although no cells of cardiovascular organs ...
Jacobsen J - - 1995
Cardiovascular and hormonal responses to anaphylactic shock were evaluated in anaesthetized pigs sensitized by natural exposure to Ascaris suum as verified by antibodies. In six animals with such antibodies, Ascaris antigen injection produced a plasma histamine increase of 52 (42-196) fold (median and range; P < 0.05), while four pigs ...
Maschio G - - 1995
Systemic hypertension has been reported to develop, or to worsen, in 20-30% of patients treated with recombinant human erythropoietin (r-HuEPO) worldwide. The greatest increases in blood pressure affect day-time systolic and night-time diastolic blood pressure. Hypertension may develop in some patients as early as 2 weeks and in others as ...
Whitworth C E - - 1994
Spontaneous development of malignant phase hypertension in TGR(mREN2)27 heterozygotes occurs as a consequence of crossing TGR(mREN2)27 homozygotes with Edinburgh Sprague-Dawley rats. Similarities to human malignant phase hypertension are seen with an accelerated rise in blood pressure, fibrinoid necrosis of renal afferent arterioles, renal failure and evidence of renin-angiotensin system activation. ...
Kiowski W - - 1994
BACKGROUND: The contribution of nonangiotensinergic effects of converting enzyme inhibitors to their hemodynamic effects in patients with chronic heart failure is not clear. A comparison of the effects of renin and converting enzyme inhibition should help to clarify this issue. METHODS AND RESULTS: Thirty-six patients with chronic heart failure (New ...
Paul M - - 1994
Numerous in vitro studies have demonstrated that angiotensin II has distinctive cellular effects in the cardiovascular system, independent from its effects on blood pressure. These have led to the hypothesis that activation of the angiotensin system in the heart could be of functional relevance for the adaptive processes in several ...
Vacca G - - 1994
It has recently been shown that distension of the stomach in anesthetized pigs causes reflex hemodynamic responses through efferent sympathetic mechanisms. The present study was undertaken to investigate whether these mechanisms include activation of the renin-angiotensin system. In twelve anesthetized pigs, intragastric balloons were distended for periods of 30 minutes ...
Ishibashi K - - 1994
The mechanism by which excessive NaCl intake raises blood pressure has not been fully clarified. The present study was undertaken in 87 Japanese inpatients with essential hypertension to investigate the interrelation among effects of age, sex and the renin-angiotensin system on NaCl sensitivity. After ingesting a regular NaCl diet (170 ...
Hernández-Llamas G - - 1994
Acute unilateral ureteral obstruction (AUUO) has been associated to a blood pressure increase, presumably secondary to activation of the renin-angiotensin system (RAS), since the obstructed kidney increases renin secretion (Ref. 8). In an attempt to delineate the role of the RAS in this hypertensive model, we acutely obstructed the ureter ...
Scholz H - - 1994
In this study we examined the role of calcium ions in the control of renin release by the renal artery pressure. For this purpose renin secretion rates (RSR) were measured in isolated rat kidneys perfused at pressures of 140, 100, 80 and 40 mmHg (19, 13, 11, 5 kPa) with ...
Frishman W H - - 1994
The renin-angiotensin system (RAS) functions as a primary regulator in the short-term and long-term control of blood pressure. Pharmacologic inhibition of the RAS with angiotensin-converting enzyme (ACE) inhibition is effective for treating systemic hypertension and congestive heart failure. As a more specific therapy, the development of renin inhibitors has evolved ...
Kool M J - - 1994
Diurnal variation has been demonstrated for blood pressure and heart function. Several hormones influence these hemodynamic parameters. This study investigates the diurnal variation in plasma prorenin in relation to renin, atrial natriuretic peptide (ANP), norepinephrine, and hemodynamic changes. Circulating plasma prorenin may be able to serve as a marker for ...
Ghio S - - 1994
OBJECTIVE: To investigate whether the susceptibility to tolerance to glyceryl trinitrate is similar in different vascular beds in patients with chronic heart failure. PATIENTS: Twenty patients with heart failure underwent a continuous infusion of glyceryl trinitrate over 24 hours followed by administration of N-acetylcysteine (5 g intravenously) in a bolus. ...
Linz W - - 1994
The renin inhibitory effect of the non-peptide renin inhibitor S 2864 (N-[N-(3-(4-Amino-1-piperidinyl-carbonyl)-2(R)-benzylpropionyl)-L- histidinyl]-(2S,3R,4S)-1-cyclohexyl-3,4-dihydroxy-6(2-pyridyl)-hexane-2- amide acetate, CAS 135683-92-0) was characterized in vitro and in vivo in primates. In vitro, S 2864 inhibited the activity of purified human plasma renin with an IC50 of 3.8 x 10(-10) mol/l and did not affect ...
Hegbrant J - - 1994
Blood pressure stability is better during cold hemodialysis (HD). This has mainly been attributed to a more pronounced sympathetic activation during cold than during warm HD. The authors studied the effect of dialysate temperature on vasoactive peptides, noradrenaline (NA), and renin (PRA). Ten hemodynamically stable patients were dialyzed for 240 ...
Riley D J - - 1994
Progressive systolic dysfunction of the heart results in a broad array of physiologic compensatory mechanisms within the kidney. These mechanisms are primarily stimulated by diminution of the effective arterial blood volume and resultant activation of a biochemical cascade of neurohormonal responses, including activation of the renin-angiotensin-aldosterone system and enhanced release ...
Gould A B - - 1994
We compared some of our latest experiments on blood pressure control and erythrocytosis in spontaneously hypertensive rats with Gaar's computer-simulated studies, which suggest that erythrocytosis is a key to understanding the hemodynamic changes in hypertension. We tested two of Gaar's several predictions: (i) peripheral vascular resistance decreases when the feedback ...
Johnson R A - - 1994
The influence of renal perfusion pressure on renin release was examined in rats administered the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME). Compared with the control plasma renin of 6.0 +/- 0.7 ng angiotensin I (ANG I).ml-1.h-1, plasma renin activity was suppressed (1.8 +/- 0.2 ng ANG I.ml-1.h-1, P ...
Thrasher T N - - 1994
The high-pressure or arterial baroreceptors and low-pressure or atrial receptors are believed to participate in the reflex control of arginine vasopressin (AVP) and renin secretion. The current concept of the control system is that at normal blood volume and pressure, afferent impulses from the receptors tonically inhibit central mechanisms controlling ...
Veglio F - - 1994
The acute effects of doxazosin, a new selective alpha-1 adrenergic blocking agent, on blood pressure, heart rate, and on some circulating vasoactive hormones, such as plasma renin activity, catecholamines, serotonin and endothelin-1 in ten healthy normotensive volunteers and eight moderate-severe essential hypertensives were studied. Two milligrams doxazosin was administered orally ...
Weaver D - - 1994
Xeric-adaptation was studied during 28 days of total water deprivation (TWD) in Notomys alexis. Beyond 7 days, the initial reductions in body weight and increases in haematocrit, plasma renin and juxtaglomerular (JG) cell morphological activity returned to normal. Mus musculus showed similar changes at 7 days but could not be ...
Hopf H B - - 1994
BACKGROUND: The renin-angiotensin and vasopressin systems, in addition to the sympathetic system, are important backup mechanisms for maintaining arterial blood pressure during circulatory challenges. We tested the hypothesis that preganglionic sympathetic blockade by thoracic epidural anesthesia interferes with the functional integrity of the renin-angiotensin system. METHODS: Renin concentrations were assessed ...
Zusman R M - - 1994
The hemodynamic and humoral effects of the specific human renin inhibitor R-PEP-27 were studied in six normal human subjects on low and high sodium intake diets. An intravenous infusion of R-PEP-27 (0.5 to 16 micrograms/min/kg body wt) reduced blood pressure in a dose-dependent fashion; the mean arterial blood pressure at ...
Azizi M - - 1994
OBJECTIVE: To assess the participation of the renin-angiotensin system in the blood pressure regulation of essential hypertensive patients through acute specific renin inhibition. DESIGN AND METHODS: Fifty-three consecutive untreated hypertensive patients (mean +/- SD age 55 +/- 10 years, 42 male) were investigated on their usual sodium diet in a ...
Agostoni P - - 1994
OBJECTIVES: This study was designed to investigate whether a subclinical accumulation of fluid in the lung interstitium associated with moderate congestive heart failure interferes with the patient's functional capacity, and whether furosemide treatment can promote reabsorption of the excessive fluid. BACKGROUND: In patients with moderate congestive heart failure, pulmonary overhydration ...
O'Donnell C P - - 1994
Hypovolemia activates reflexes that stimulate secretion of renin and arginine vasopressin (AVP). A large body of evidence, obtained mainly in anesthetized preparations, supports the hypothesis that unloading cardiac receptors stimulates increases in plasma AVP and renin activity (PRA). We have observed significant increases in PRA before any change in either ...
Naftilan A J - - 1994
In recent years numerous data have given evidence that the tissue renin-angiotensin system may play an equal or perhaps an even more important role than the circulating renin-angiotensin system in numerous physiologic processes. This was first suggested by the observation that the blood pressure lowering effect of angiotension-converting enzyme (ACE) ...
West M J - - 1994
1. The associations between left ventricular hypertrophy (LVH) and specific alleles of the renin and angiotensin-converting enzyme (ACE) genes were studied in patients with essential hypertension and normal blood pressure. 2. LVH was present in 42% of those with essential hypertension (n = 72) and 17% of those with normal ...
Gerber L M - - 1994
OBJECTIVE: To determine prospectively the relationship between the renin-sodium profile and the renin response to captopril challenge in patients with essential hypertension. DESIGN: A standard captopril test was performed in 108 uncomplicated, untreated hypertensive subjects with normal renal function and urinary sodium excretion in the range 50-240 mmol/day. The subjects ...
Reinhardt H W - - 1994
This study examines whether an increase in renal perfusion pressure (RPP) is necessary to escape endogenously stimulated Na- and water-retaining mechanisms. In seven dogs stimulation was accomplished by a servo-controlled reduction of RPP (rRPP) below the threshold for pressure-dependent renin release for 4 days. Oral intake was standardized. Plasma renin ...
Eng E - - 1994
Angiotensin II (AII) is a vasoconstrictive peptide with hypertrophic and mitogenic effects on many cell types. Previous studies have shown that in vivo administration of AII in rats results in proliferation of, and phenotypic changes in, many renal cell populations, but in doses also causing hypertension. Thus, it was not ...
Peters T K - - 1994
1. The interaction of electrical stimulation of the carotid sinus nerves (carotid sinus nerve stimulation, CSNS) with mechanisms of renin release was studied in conscious and unrestrained resting beagle dogs receiving a standardized diet (sodium intake, 4.5 mmol/kg bodyweight (bw); water intake, 91 mL/kg bw). 2. By CSNS, mean arterial ...
Lichardus B - - 1994
Transgenic mice overexpressing a transthyretin promoter-ANF structural fusion gene have a life-long reduction in arterial blood pressure compared to nontransgenic littermates. The present study was designed to test the hypothesis that the high plasma level of ANF in the transgenic mice inhibits the renin-angiotensin and/or vasopressin systems, thereby causing the ...
Taddei S - - 1994
Experimental data indicate the existence of a vascular tissue renin-angiotensin system in several different vessels from various animal models. Active renin can be locally synthesized into the vessel wall or taken up from circulating plasma to produce vascular angiotensin II. Using the human forearm technique, we produced evidence indicating the ...
Reid I A - - 1994
Studies in vitro and in vivo have implicated nitric oxide in the control of renin secretion. In the present study, the effect of inhibition of nitric oxide synthesis with NG-nitro-L-arginine methyl ester hydrochloride (L-NAME) on the renin secretory response to beta-adrenergic stimulation was investigated in conscious, chronically prepared rabbits. Intravenous ...
Silke B - - 1994
An immediate improvement in haemodynamic variables and cardiac performance is achieved in chronic heart failure following diuretic therapy, primarily due to reductions in plasma and extracellular fluid volumes. Humoral markers of these alterations are increased plasma renin, angiotensin and aldosterone levels; these increase maximally over the first week of treatment ...
Lee H S - - 1994
Shih-Hsüan [Sipseon (EX-UE-11)] are Curious loci lying outside of the meridians on the tips of each finger. These loci have long been the acupuncture sites for the treatment of cardiovascular disease in oriental medicine. Alterations in the renin-angiotensin system have been considered as the pathophysiological basis of the origin and/or ...
Nagano M - - 1994
Although the activity of the renin-angiotensin system is known to decrease with age, the antihypertensive efficacy of angiotensin-converting enzyme (ACE) inhibitors has been demonstrated in the elderly. To examine the role of the renin-angiotensin system in hypertension in the elderly, we evaluated the antihypertensive response to enalapril and to TCV-116, ...
Thel M C - - 1993
We have described a patient, subsequently found to have polyarteritis, whose renin activity was 60 times normal, a level associated with malignant hypertension and severe renal artery stenosis. The severe hypertension and its resistance to multiple medications in the face of a dramatic response to low-dose enalapril imply the renin-angiotensin ...
Rosenthal J - - 1993
The role of the renin-angiotensin system in cardiovascular function and disease has long been recognized. The renin-angiotensin system was originally thought to be only active in the plasma as a circulating endocrine system, controlling blood pressure and electrolyte homeostasis. The recent introduction of new biotechnologies to cardiovascular research has demonstrated ...
Brunner H R - - 1993
The tools which have led to a better understanding of the role of the renin-angiotensin system in determining the tone of peripheral arteries in cardiovascular disease consist of highly specific and sensitive methods to measure the different components of the renin-angiotensin system and in specific probes used to inhibit the ...
Zayas V M - - 1993
To assess the relative contributions of neural and nonneural stimuli of renin secretion, the effects of an alpha 1-agonist, phenylephrine (Phe), or a beta-agonist, epinephrine (Epi), on plasma renin activity (PRA), renal blood flow (RBF), and glomerular filtration rate (GFR) were compared during sympathetic blockade with epidural hypotensive anesthesia [mean ...
Hou C H - - 1993
We examined the antihypertensive response to enalapril and its relation to the changes of the renin-angiotensin-aldosterone axis (RAA) in essential hypertensive patients. The responders, whose blood pressure reduced after enalapril administration, had significant elevation of plasma renin activity after enalapril (7.5 +/- 4.0 to 31.9 +/- 10 ng/mL/h, p < ...
Ruzicka M - - 1993
Besides cardiac volume overload, cardiac sympathetic activity and the renin-angiotensin system (RAS) are activated by arterial vasodilators such as minoxidil. To evaluate the possible involvement of the RAS in the development of minoxidil-induced cardiac hypertrophy, we assessed in normotensive rats minoxidil-induced changes in cardiac and plasma renin activity (PRA) and ...
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