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Results 351 - 400 of 708
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Tajima F - - 1999
BACKGROUND: The hydrostatic pressure gradient during head-out water immersion (HOI) causes a blood shift from the legs into the thoracic cavity to stretch the receptors in the cardiac atria and results in a diuresis in hydrated subjects. The present study was conducted to examine whether the HOI-induced diuresis and related ...
Schulz O - - 1999
BACKGROUND: Heart transplantation is associated with a reduction of the neurohumoral activation seen in patients with severe congestive heart failure. In this study, we investigated whether pharmacologically induced complex hemodynamic improvement during assessment of reversibility of pulmonary hypertension with a phosphodiesterase inhibitor is able to induce neurohormonal changes of diagnostic ...
Stewart P M - - 1999
Hypertension with hypokalaemia and suppression of plasma renin activity is known as mineralocorticoid hypertension. Although mineralocorticoid hypertension accounts for a small number of patients labelled as having "essential" hypertension, it is a potentially reversible cause of high blood pressure. The most common cause of mineralocorticoid hypertension is probably primary aldosteronism; ...
Hummler E - - 1999
Arterial blood pressure is critically dependent on sodium balance. The kidney is the key player in maintaining sodium homeostasis. Aldosterone-dependent epithelial sodium transport in the distal nephron is mediated by the highly selective, amiloride-sensitive epithelial sodium channel (ENaC). Direct evidence that dysfunction of ENaC participates in blood pressure regulation has ...
Zavagli G - - 1999
The infusion of 40 mEq potassium (aspartate) in 250 ml isotonic 1-fructose at a rate of 20 mEq/h into 5 patients (34-56 years old) with aldosteronoma and 2 patients with bilateral primary aldosteronism consistently raised their mean arterial pressure by 15-20 mmHg. Their pressure values returned to the baseline levels ...
Sato A - - 1999
There is increasing evidence for important cardiovascular effects of aldosterone via classical mineralocorticoid receptors in the heart. Administration of aldosterone with excess salt produces both cardiac hypertrophy and interstitial cardiac fibrosis in rats, and concomitant administration of potassium canrenoate at a dose that only modestly lowers blood pressure completely blocks ...
Stoynev A G - - 1999
The circadian rhythm of arterial pressure (AP) is not a passive consequence of the impact of exogenous factors. Endogenous mechanisms play an important role in the generation and maintenance of AP rhythm. The adaptation of the exogenous components of AP rhythm to the demands of the environment is modulated by ...
Veglio F - - 1999
The purpose of this study was to evaluate if changes in vascular properties were related to baroreflex function in patients with primary aldosteronism. Twenty-three patients with primary aldosteronism, 22 essential hypertensive patients and 16 normal controls were studied. Continuous finger blood pressure (BP) was recorded by Portapres device during supine ...
Rocha R - - 1999
Stroke-prone spontaneously hypertensive rats (SHRSP) on 1% NaCl drinking solution and Stroke-Prone Rodent Diet develop severe hypertension and glomerular and vascular lesions characteristic of thrombotic microangiopathy seen in malignant nephrosclerosis. We recently reported that spironolactone, a mineralocorticoid receptor antagonist, markedly reduced proteinuria and malignant nephrosclerotic lesions in these animals. This ...
Fridman K U - - 1999
The effects of the angiotensin II receptor blocker candesartan cilexetil on systemic and forearm haemodynamics and baroreceptor sensitivity were evaluated in this randomized, placebo-controlled, double-blind, crossover study. After a 4-week placebo run-in period, 22 patients with essential hypertension (diastolic blood pressure 100-114 mmHg) were randomized to receive either candesartan cilexetil ...
Spitzer D - - 1998
A 46-year old female nursing sister was admitted to three different hospitals because of blood pressure crises of 300/150 mmHg which occurred up to six times a day. The rises in blood pressure were accompanied by headache, tachycardia and outbreaks of sweating. Raised catecholamine concentrations were repeatedly measured in the ...
Yee K M - - 1998
1. Recent animal evidence suggests that aldosterone, like angiotensin II, may possess detrimental autonomic modulating properties. Aldosterone has been shown to impair the baroreflex response in animal models. This study is designed to test the hypothesis that aldosterone directly attenuates the baroreflex in vivo in man.2. Fourteen healthy male volunteers ...
Proye C A - - 1998
BACKGROUND: Despite cure of primary aldosteronism by surgical resection, hypertension persists postoperatively in 30% to 50% of patients. The aim of this study was to determine factors influencing long-term outcome of blood pressure after unilateral adrenalectomy for primary aldosteronism. METHODS: Records of 100 patients who underwent unilateral adrenalectomy for primary ...
Kelly J J - - 1998
1. In humans, the hypertensive effects of adrenocorticotropic hormone (ACTH) infusion are reproduced by intravenous or oral cortisol. Oral cortisol increases blood pressure in a dose-dependent fashion. At a dose of 80-200 mg/day, the peak increases in systolic pressure are of the order of 15 mmHg. Increases in blood pressure ...
Wehling M - - 1998
Rapid nongenomic in vitro effects of aldosterone have been demonstrated recently in cultured vascular smooth muscle and endothelial cells. But there is, as yet, little evidence for corresponding in vivo effects. The present study thus investigates the rapid nongenomic effects of aldosterone on human cardiovascular function. In a double-blind placebo-controlled ...
Tominaga M - - 1998
Resection of pheochromocytoma is associated with potential risks of hypertensive crises and serious arrhythmias due to massive release of catecholamines from the tumor. We report our surgical experience with complete inferior vena caval isolation and extracorporeal charcoal hemoperfusion (IVCI-CHP), which were performed to prevent systemic exposure to catecholamines during surgical ...
Pojoga L - - 1998
The renin-angiotensin-aldosterone system plays an important role in large artery structure and blood pressure homeostasis. Among the genes coding for different components of this system, the aldosterone synthase (CYP11B2) gene could play an important role, but has been less investigated. We examined the role of two variations of the aldosterone ...
Luchsinger A - - 1998
This study was conducted in normotensive and hypertensive subjects at the Vargas Hospital of Caracas. Normotensive subjects received, in a cross-over fashion, placebo, metoclopramide (MTC), or domperidone (DOMP), 40 mg of each drug, daily for 1 week. The first group of patients under placebo for 1 week received a single ...
Bartter F C - - 1998
A new syndrome, characterized by hypertrophy and hyperplasia of the juxtaglomerular apparatus of the kidneys, aldosteronism resulting from adrenal cortical hyperplasia, and persistently normal blood pressure is described in two patients. Overproduction of aldosterone could not be prevented by sodium loading or by administration of albumin intravenously; it was associated ...
Fletcher A K - - 1998
Correction of the causes of secondary forms of hypertension usually restores blood pressure to normal. Hypothyroidism is a potentially important but overlooked cause of hypertension and restoration of euthyroidism with thyroxine therapy usually results in a substantial reduction in both systolic and diastolic blood pressure, especially in younger subjects. The ...
Rizzoni D - - 1998
The aim of our study was to evaluate the relationships between endothelial function, small resistance artery structure, and blood pressure in patients with primary or secondary hypertension. Sixty subjects were included in the study: 9 patients with pheochromocytoma, 10 with primary aldosteronism, 17 with renovascular hypertension, and 13 with essential ...
Sohn C I - - 1998
A 40-year-old woman was admitted because of abdominal pain and diarrhea. She sometimes experienced paroxysmal hypertension, sweating, headache, and palpitation. Sigmoidoscopic findings showed well-demarcated diffuse mucosal edema, hyperemia, and easy touch bleeding from distal descending colon up to the splenic flexure area. Barium x-ray showed loss of haustral marking, thumb ...
Miyazawa K - - 1998
A 49-year-old male was diagnosed as having primary aldosteronism at age 39, and he was treated with antihypertensive drugs. In 1995, a computed tomogram revealed a mass in the right adrenal gland. Radiological examinations and endocrinological data revealed the presence of a pheochromocytoma in the right and an adrenocortical tumor ...
Blacher J - - 1997
We previously observed that, in subjects with essential hypertension, acute ouabain constricts the brachial artery diameter in the presence of spironolactone treatment, a finding that is not observed in the absence of aldosterone antagonist and therefore suggests a specific effect of aldosterone on the arterial wall. To evaluate whether aldosterone ...
Wang H - - 1997
OBJECTIVE: To compare the effect of ouabain on the blood pressure of rats with that of digoxin to find the evidences of the relationship between endogenous ouabain (EO) and development of hypertension. METHODS: Sprague-Dawley rats, which were divided into 3 groups, were infused with ouabain (23 x 75 micrograms.kg-1/day, i.p.), ...
Jespersen B - - 1997
As it has been suggested that parathyroid hormone (PTH) is implicated in the pathophysiology of essential hypertension, the effects of PTH(1-34) were assessed during infusion over 120 min in ten men with essential hypertension and in ten healthy men. Ionized calcium was kept constant by a clamping technique. Mean arterial ...
Thorens J B - - 1997
The aim of this study was to investigate the haemodynamic and endocrinological effects of noninvasive positive pressure ventilation (NIPPV). Eleven patients with oedema and recent hypercapnic and hypoxaemic worsening of a chronic respiratory insufficiency were included. Echocardiography, cardiac radionuclide assessment, blood catecholamines, salt and water handling hormones were measured at ...
Zweiker R - - 1997
Pheochromocytoma endures as a life-threatening disorder. In the absence of systemic hypertension, diagnosis may be difficult. We present a 46-year-old normotensive male with a history of presyncope. One of these episodes could be documented, and revealed symptomatic bradycardia suspicious of sinus node arrest. Due to hints of an elevated sympathetic ...
Takami H - - 1997
A patient with asymptomatic pheochromocytoma associated with catecholamine hypersecretion but no hypertension was treated by right laparoscopic adrenalectomy. The 63-year-old male patient was referred to us for treatment of an incidentaloma. The diameter of the adrenal tumor was 50 mm, and the peripheral blood nonrepinephrine level was 1.12 ng/ml (normal ...
White P C - - 1997
Genetic defects in aldosterone biosynthesis and action affect blood pressure and electrolyte homeostasis. Aldosterone synthase deficiency, salt-wasting forms of congenital adrenal hyperplasia, and adrenal hypoplasia congenita all cause aldosterone deficiency, signs of which include hyponatremia, hyperkalemia, hypovolemia, elevated plasma renin activity, and sometimes shock and death. Conversely, the inappropriate regulation ...
Bloomfield G L - - 1997
OBJECTIVE: To study the effects of elevated intra-abdominal pressure upon renal function and the renin-angiotensin-aldosterone system. MATERIALS AND METHODS: Two groups of anesthetized, ventilated swine were studied. Intra-abdominal pressure was increased in experimental animals (n = 6) by incrementally instilling an isosmotic ethylene glycol solution into the peritoneal cavity until ...
Rossi G P - - 1997
BACKGROUND: Since hyperaldosteronism has been experimentally related to myocardial interstitial fibrosis, we investigated the effects of hypertension and excess aldosterone due to aldosterone-producing adenomas (APAs) on the heart. METHODS AND RESULTS: In 52 hypertensive individuals, we performed Doppler echocardiography for estimation of left ventricular (LV) wall thickness and dimensions, transmitral ...
Haruna Y - - 1997
Long term change of renin-angiotensin-aldosterone system (RAAS) induced by bed rest and its effects on cardiovascular system are still controversial. The purpose of this study was to obtain a general conclusion on these questions by analyzing our two 20-days horizontal bed rest experiments in past two years with 18 subjects. ...
Lee H S - - 1997
The aim of this study was to investigate the effects of moxibustion at the meridian points BL-15 (Xin-shu) and BL-27 (Xiao-chang-shu) on renal function, systolic blood pressure, plasma levels of renin activity, aldosterone and atrial natriuretic peptide in spontaneously hypertensive rats. The results showed that urine volume increased significantly after ...
Pessina A C - - 1997
Left ventricular hypertrophy (LVH) is a common finding in hypertension and represents a detrimental outcome since it is associated with increased morbidity and mortality. For similar elevation of blood pressure the severity and type of LVH vary considerably in relation to several factors. Compelling evidence suggests that both the renin-angiotensin ...
Fardella C E - - 1996
Low renin hypertension (LRH), which accounts for 10-20% of patients with idiopathic "essential" hypertension, bears hormonal similarities to mineralocorticoid-induced hypertension, but elevated mineralocorticoid concentrations have not been found. Some patients with LRH have normal, rather than suppressed, plasma aldosterone concentrations, so that the ratio of aldosterone concentration to PRA (Aldo/PRA) ...
Hui Y - - 1996
OBJECTIVE: To evaluate the relationship between certain humoral factors and left ventricular hypertrophy (LVH) in essential hypertension. PATIENTS AND METHODS: 62 essential hypertension (EH) patients (32 men, 30 women; mean age, 55 years) and 20 normotensive healthy subjects (10 men, 10 women: mean age, 52 years) were studied. EH patients ...
Rizzoni D - - 1996
It has been proposed that several neurohumoral factors may be involved in the genesis of vascular structural changes (remodeling or hypertrophy) frequently observed in essential hypertension. Therefore, in this study we investigated vascular structural alterations of subcutaneous small resistance arteries in patients with secondary forms of hypertension. The study included ...
Dal Palù C - - 1996
A minimum level of blood pressure is necessary for atherosclerosis to develop, even in the presence of hypercholesterolemia. Experimentally and clinically we have both examples of atherosclerosis in which hypercholesterolemia is the dominant pathogenetic factor and others in which hypertension prevails (BBWT). The pathogenetic role of hypertension may be direct ...
Jensen L W - - 1996
The aim of this study was to assess the blood pressure profile and vasoactive hormones in valvular aortic disease. Thirteen aortic stenosis and/or aortic regurgitation patients were matched with 13 control subjects. Ambulatory blood pressure monitoring was performed for 24 h. Arterial and venous plasma concentrations of renin, angiotensin II, ...
Portaluppi F - - 1996
The temporal organization of blood pressure is mainly controlled by neuroendocrine mechanisms. The monoaminergic systems appear to integrate the major driving factors of temporal variability, but evidence also indicates a role of the hypothalamic-pituitary-adrenal, hypothalamic-pituitary-thyroid, opioid, renin-angiotensin-aldosterone, and endothelial systems as well as other vasoactive peptides. Although their hormonal secretions ...
Tresham J J - - 1996
The possibility that corticotropin (ACTH)-induced hypertension results from a direct central effect of the adrenocortical steroids released by ACTH was investigated in sheep. Using two approaches, steroid levels were increased in the brain while peripheral levels remained sub-pressor. The blood pressure response to intravenous infusion of a combination of 7 ...
Rossi G P - - 1996
We investigated the effects on the heart of hypertension due to the excess of aldosterone and suppression of the renin-angiotensin system caused by primary aldosteronism with M-mode echocardiography and transmitral Doppler flow velocity measurements. We studied 34 consecutive patients with primary aldosteronism and 34 with essential hypertension individually matched for ...
Young M J - - 1996
In uninephrectomized rats on 1% NaCl solution to drink, aldosterone (0.75 micrograms/h subcutaneously for 8 weeks) raises blood pressure and causes marked interstitial and perivascular cardiac fibrosis, effects not seen in animals on a low salt intake. In extending these initial findings, we have shown that cardiac fibrosis (i) is ...
Ou Y C - - 1996
BACKGROUND: Primary aldosteronism (PA) is a rare but potentially curable cause of hypertension. Between October 1982 and November 1994, 30 patients of PA received unilateral adrenalectomy with a long-term follow up (mean:60.3 months). Nineteen (63.3%) cases were cured (Group 1); 11(36.7%) cases were improved (Group 2). The purpose of this ...
Smith M C - - 1995
The major antihypertensive effect of losartan, a nonpeptide angiotensin II antagonist, is thought to be due to inhibition of the pressor effects of angiotensin II. It is possible, however, that losartan alters the synthesis of vasodilator or vasoconstrictor prostaglandins (PG), thus contributing to its antihypertensive effect. Sixteen postmenopausal women with ...
Munakata M - - 1995
OBJECTIVE: Reduced baroreflex sensitivity has been reported in several kinds of human hypertension. However, the nature of the baroreceptor-heart rate reflex in hypertension due to excess mineralocorticoid has never been fully explored. PATIENTS AND METHODS: Thirty patients with primary aldosteronism, 60 patients with essential hypertension (World Health organization stages I ...
Young M - - 1995
Uninephrectomized rats maintained on 1.0% NaCl to drink and infused with aldosterone (0.75 microgram/h) for 8 wk have previously been shown to develop hypertension, cardiac hypertrophy, and cardiac fibrosis. In the present study we have shown that K+ supplementation (1.0% NaCl plus 0.4% KCl drinking solution) alters neither the interstitial ...
Nakamoto H - - 1995
OBJECTIVE: To determine whether the central nervous system has a pressor or a depressor role in glucocorticoid-induced hypertension. METHODS: Intracerebroventricular dexamethasone or its receptor antagonist, RU 38486, was administered in 20 trained conscious dogs. In addition, intracerebroventricular RU 38486 was administered in dogs treated with oral dexamethasone. RESULTS: Intracerebroventricular dexamethasone ...
Velasco Manuel - - 1995
Nine patients with mild or moderate essential hypertension were studied at the Vargas Hospital of Caracas, Venezuela. After antihypertensive treatment discontinuation, all patients were placed on placebo during a 1-week period, after which domperidone, a peripheral DA(2) dopaminergic blocker, was orally administered at the dose of 20 mg every 12 ...
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