Search Results
Results 451 - 500 of 712
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Engelke K A - - 1996
We tested the hypothesis that one bout of maximal exercise performed at the conclusion of prolonged simulated microgravity would improve blood pressure stability during an orthostatic challenge. Heart rate (HR), mean arterial blood pressure (MAP), norepinephrine (NE), epinephrine (E), arginine vasopressin (AVP), plasma renin activity (PRA), atrial natriuretic peptide (ANP), ...
Tucker V L - - 1996
The relationship between plasma immunoreactive atrial natriuretic peptide (irANP) and radiolabeled albumin clearance (CBSA) in multiple tissues after graded volume stimuli was examined. To obtain a pure volume stimulus, pentobarbital sodium-anesthetized rats (5 or 6 per group) were equilibrated with a reservoir of blood by a femoral arteriovenous shunt, and ...
Leuenberger U - - 1996
To determine whether prejunctional angiotensin II receptors facilitate norepinephrine (NE) release during exercise, normal volunteers exercised at approximately 25 or approximately 65% of maximal O2 consumption (VO2max) on two occasions. Steady-state NE kinetics were determined at rest and during exercise by using infusions of [3H]NE. Arterial plasma NE and [3H]NE ...
Lang C C - - 1996
BACKGROUND: One suggested mechanism for the reduction in mortality rates resulting from the use of angiotensin converting enzyme inhibitors in congestive heart failure is the inhibition of the angiotensin II-mediated norepinephrine release. Direct evidence for this mechanism is lacking in humans. SUBJECTS AND METHODS: We examined the effects of captopril, ...
McFarlane A C - - 1996
1. Atrial natriuretic factor (ANF) and its analogues have been shown previously to inhibit corticotrophin-releasing hormone (CRH)-induced adrenocorticotrophin (ACTH) release, both in vivo and in vitro, and it has been suggested that ANF may be a, or the, physiological ACTH-inhibitory factor. To determine whether ANF is relevant in the regulation ...
Dunn A L - - 1996
Regional changes in concentrations of brain norepinephrine [NE] and its metabolites after chronic exercise have not been described for exercise protocols not confounded by other stressors. We examined levels of [NE], 3-methoxy-4-hydroxyphenylglycol [MHPG], and 3,4-dihydroxyphenylglycol [DHPG] in the frontal cortex, hippocampus, pons-medulla, and spinal cord after 8 wk of exercise. ...
Naumann M - - 1996
While several radiological findings point towards the basal ganglia as a possible anatomical site of the lesion in dystonia patients the biochemical basis of the disorder is still unknown. 5-Hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA) levels-the respective metabolites of serotonin and dopamine-were measured in lumbar cerebrospinal fluid (lCSF) of ...
Geny B - - 1996
Exercise tolerance of heart transplant patients is often limited. Central and peripheral factors have been proposed to explain such exercise limitation but, to date, the leading factors remain to be determined. We examined how a short-term endurance exercise training programme may improve exercise capacity after heart transplantation, and whether atrial ...
Lind H - - 1996
The aim of this study was to investigate the regulation of two sensory peptides calcitonin gene-related peptide (CGRP) and substance P, reflected as circulating levels during provocation of the sympathetic nervous system. Levels in hypertensives, diabetics (NIDDM) and controls were assayed before, during and after an exercise test (average work ...
Jahnke A W - - 1995
Bicaval anastomoses in orthotopic cardiac transplantation offer the advantage of preserving the right atrial geometry. To elucidate the impact of this anastomotic technique on atrial natriuretic peptide plasma levels at rest and with exercise, nine patients were submitted to a symptom-limited supine exercise test. Atrial natriuretic peptide plasma levels in ...
Mandroukas K - - 1995
The aim of this study was to evaluate and compare the plasma concentration of atrial natriuretic factor (ANF), K+, Na+, blood lactate, heart rate, and blood pressure in moderately trained women. Ten healthy women were studied on a cycle ergometer during 20 min of constant submaximal and maximal exercise, as ...
Marumoto K - - 1995
To assess the role of atrial and brain natriuretic peptides (ANP, BNP) in maintaining cardiac performance at rest and during exercise in patients with cardiac dysfunction, we measured plasma levels of ANP and BNP during 201Tl dynamic exercise testing in 32 patients with angiographically proven old myocardial infarction (OMI) and ...
Braam B - - 1995
The present study was designed to investigate whether nitric oxide (NO) antagonizes angiotensin II (Ang II) in modulating the tubuloglomerular feedback (TGF) system. Maximum TGF responses were assessed by evaluating stop-flow pressure (SFP) responses to late proximal perfusion with artificial tubular fluid (40 nl/min). Peritubular capillary (PTC) infusion of 10(-3) ...
Birnbaum B A - - 1995
OBJECTIVE: The purpose of this study was to compare the degree and timing of peak hepatic enhancement, optimal scanning intervals, and optimal delay times of moderate-rate uniphasic and biphasic contrast material injection protocols for hepatic helical CT. MATERIALS AND METHODS: One hundred fifty patients were randomized into three injection protocols, ...
Azizi C - - 1995
Spontaneous and experimental rises of intracardiac pressure and/or volume increase the level of atrial natriuretic (ANP) mRNA in rat atrial tissue. There is expanding evidence that ANP synthesis is increased in the ventricle under such conditions. However, little is known with regard to the myocardial ANP synthesis response to physical ...
Antezana A M - - 1995
Acute and chronic exposure to high-altitude (HA) hypoxia inhibits the renin-angiotensin-aldosterone system and may modify the release of atrial natriuretic peptide (ANP) in sea-level (SL) natives. In HA natives, the release of these hormones could be influenced by changes in blood volume or pulmonary arterial pressure. Twenty-four men residing in ...
Angus R M - - 1995
The reduced ability of inhaled compared with intravenous atrial natriuretic peptide (ANP) to modify bronchial reactivity and tone may be due to degradation of the peptide by neutral endopeptidase (NEP) within the airways. To test this hypothesis, we have examined the effect of thiorphan, an NEP inhibitor, on the protection ...
Madsen B K - - 1995
Survival in congestive heart failure is related to plasma catecholamines and atrial natriuretic peptide at rest, but the prognostic importance of changes during exercise is unknown. The aim of this study was to evaluate the prognostic value of catecholamines and atrial natriuretic peptide at rest and during maximal exercise in ...
Smit A J - - 1995
Close relations exist between the peripheral dopaminergic system, and the sympathetic nervous and renin-angiotensin-aldosterone system: D1 dopamine receptor stimulation-induced vasodilation may activate the sympathetic nervous and renin-angiotensin system in vivo, presynaptic D2 dopamine receptor stimulation is known to inhibit stimulated norepinephrine release from sympathetic nerve terminals, in experimental conditions both ...
Tanaka M - - 1995
To determine the major stimuli for the release of brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP), we measured their plasma concentrations in 14 normal subjects and 19 patients with essential hypertension during exercise with a bicycle ergometer. The plasma levels of both hormones at baseline were significantly higher ...
Pagliari R - - 1995
Cortical norepinephrine (NE) release and metabolism were studied by using chronic microdialysis in rats performing a treadmill exercise at 25 m/min with a 3% slope. Cortical microdialysates and peripheral blood were collected at rest, during 1- or 2-h treadmill running, and for 1 h after exercise. Microdialysate NE and its ...
Kokkonen U M - - 1995
To study the exercise-induced changes in atrial natriuretic peptide (ANP), a hormone with cardiovascular and renal effects, an incremental submaximal exercise test on a high-speed treadmill was carried out with Standardbred and Finnhorse trotters, the former bred for speed and the latter originally for heavy work. Standardbreds performed the 2 ...
Marumoto K - - 1995
1. This study was conducted to assess the role of artrial and brain natriuretic peptides during acute myocardial ischaemia associated with dynamic exercise. 2. Study subjects consisted of 35 angiographically proven patients with angina pectoris and 35 angiographically normal control subjects. All subjects underwent 201Tl dynamic exercise testing. The presence ...
Ukai M - - 1995
The effects of recombinant alpha-human atrial natriuretic peptide (alpha-hANP) infusion an acute left ventricular dysfunction provoked by exercise were examined in 14 men with coronary artery disease. Patients performed symptom-limited, graded exercise on a supine bicycle ergometer. Plasma alpha-hANP and guanosine 3',5'-monophosphate (cyclic GMP) concentrations as well as hemodynamic variables ...
Stevens T L - - 1995
Asymptomatic or early left ventricular dysfunction in humans is characterized by increases in circulating atrial natriuretic peptide (ANP) without activation of the renin-angiotensin-aldosterone system (RAAS). We previously reported a canine model of early left ventricular dysfunction (ELVD) produced by rapid ventricular pacing and characterized by an identical neurohumoral profile and ...
Moe L - - 1995
The glomerular filtration rates (GFR) of 18 dogs of different breeds were estimated by simultaneously comparing the plasma decay curves of 99M-Tc-diethylenetriaminepentaacetic acid (Tc-DTPA) and the contrast medium iohexol. Nine of the dogs were clinically healthy, and nine had renal disease. After the intravenous injection of the two substances, nine ...
Huang W - - 1995
The involvement of endogenous oxytocin (OT) in the renal natriuretic response to an intravenous load of hypertonic and isotonic saline was investigated in anesthetized male rats with use of a selective OT-receptor antagonist [Mpa1,D-Tyr(Et)2,Thr4,Orn8]-OT (OT-ant). NaCl was infused (0.05 mmol.min-1.kg body wt-1 iv for 120 min) as a hypernatremic (HNa) ...
Fanciullacci M - - 1995
In this study, changes in plasma levels of calcitonin gene-related peptide (CGRP) and substance P (SP) during a spontaneous-like cluster headache attack provoked by nitroglycerin were evaluated. Peptide variations after spontaneous or sumatriptan-induced remission were also assessed. Blood was collected from the external jugular vein homolateral to the pain side ...
Dobnig H - - 1995
Plasma levels of sulfoconjugated (sc) catecholamines (CA) have been shown to be increased with activation of the sympathoadrenal system in a number of clinical settings. We evaluated the relation between scCA and clinical or hemodynamic parameters of patients with idiopathic dilated cardiomyopathy (IDC) at rest and during incremental exercise testing. ...
Lordick F - - 1995
Plasma atrial natriuretic peptide (ANP) is an endogenous vasodilator, which might counteract pulmonary hypertension due to hypoxaemia. The aim of this study was to investigate the influence of acute and chronic hypoxia on plasma (ANP) concentrations in humans. Venous plasma ANP concentrations in six healthy subjects were measured before and ...
Robichaud A - - 1995
The aim of this work was to establish the role of endogeneous ANP during a spontaneous asthma attack. Forced expiratory lung volume in 1 s (FEV1), cardiovascular parameters, and plasma ANP, cAMP, and cGMP were measured for 60 min before and 10 min after treatment with a bronchodilator in 10 ...
Flege J E - - 1995
English monolinguals and native Spanish speakers of English used a 9-point scale to rate syllable-initial stops for goodness as realizations of the English /p/ category. Voice onset time (VOT) was varied in a set of short-duration ('fast-rate') consonant-vowel (CV) stimuli, and in a set of longer-duration ('slow-rate') CV stimuli. The ...
Moriguchi A - - 1995
We investigated the underlying mechanisms of baroreflex alteration produced by intravenous angiotensin II (ANG II) by monitoring the release of amino acids from the rostral ventrolateral medulla (VLM) using a brain microdialysis technique. Reflex changes in heart rate were elicited by bolus intravenous injection of phenylephrine (2-40 micrograms/kg) before and ...
Kentsch M - - 1995
In man, chronic antihypertensive calcium antagonist treatment improves cardiac function and reduces plasma ANF concentrations. Physical exercise increases cardiac workload and plasma ANF levels. In the present study, we investigated the effects of acute administration of the dihydropyridine calcium antagonist BAY t 7207 (BAY) during bicycle exercise on plasma ANF ...
Nagashima K - - 1995
To assess the relationship between atrial natriuretic peptide (ANP) and the reduction in plasma volume (PV) during exercise, we measured changes in PV and ANP in seven male volunteers during treadmill exercise in air (AE) and with water immersion (WE) together with time control studies of rest in air and ...
Atuk N O - - 1994
Although increased plasma norepinephrine (NE) concentrations mediate vasoconstriction during episodic hypertension and hypertensive crises in patients with pheochromocytoma (Pheo), the precise origin of this circulating NE (tumor or sympathetic nerves) is not known. Dihydroxyphenylglycol (DHPG), a deaminated metabolite of NE, is formed principally in sympathetic nerve endings. Under basal conditions, ...
Fontana F - - 1994
OBJECTIVE: To investigate the effects of the endogenous opioid system on plasma atrial natriuretic factor (ANF) levels during sympathetic hyperactivity. DESIGN: We studied the young normotensive offspring of parents who both had essential hypertension, who are characterized by a hyperactive sympathetic nervous system. METHODS: We assessed plasma beta-endorphin, met-enkephalin, dynorphin ...
Leitch S P - - 1994
Catecholamines can offset the negative effect of acidosis and raised extracellular K+ concentration in the isolated rabbit heart when these factors are changed with similar kinetics and concentrations as those observed in exercise. This effect appears to be mediated by changes in Ca2+ handling in the heart. To test the ...
Baboolal K - - 1994
The effect of acute Ang II blockade on renal function in rats with reduced nephron number was assessed in micropuncture studies. The Ang II receptor blocker, losartan, was administered at a dose of 10 mg i.v. at two intervals following five-sixths renal ablation. At eight weeks following ablation, Ang II ...
Woods R L - - 1994
The influence of atrial natriuretic peptide (ANP) on the blood pressure (BP)-heart rate (HR) baroreflex was studied in conscious chronically instrumented dogs and rats. In both species, sigmoid steady-state baroreflex curves were constructed from the baroreflex changes in HR to alternating slow injections of vasopressor and vasodepressor drugs. When this ...
Noshiro T - - 1994
To investigate the potential modulating influence of angiotensin II (ANG II) on sympathetic activity in response to changes in baroreflex activity, renal and total norepinephrine (NE) spillover rates were examined during sodium nitroprusside (SNP) and phenylephrine (PE) infusions in four groups of conscious rabbits: 1) saline (control); 2) subpressor ANG ...
Liguori A - - 1994
The neurohormonal changes occur early, have important prognostic value, and may play a role in the evolution and progression of heart failure in man. Atrial natriuretic factor (ANF) is a natriuretic and vasorelaxant peptide. Previous studies indicated that plasma ANF provides prognostic information and, ANF levels closely related to both ...
Nose H - - 1994
To investigate the relationship between right atrial pressure (RAP) and atrial natriuretic peptide (ANP) release during prolonged exercise in a hot environment (30 degrees C, 20% relative humidity), we studied with a Swan-Ganz catheter five male volunteers exercising on a cycle ergometer at 60% of peak aerobic power for 50 ...
Mukaddam-Daher S C - - 1994
Angiotensin II (AngII) influences the regulation of mean arterial pressure (MAP) through numerous mechanisms, including an action of circulating AngII on the brain to alter autonomic activity. We have obtained evidence that the relative importance of this effect is increased during pregnancy. Consequently, these studies were undertaken to assess the ...
Bussières-Chafe L M - - 1994
OBJECTIVE: To determine the influence of body posture and central hemodynamics on the plasma levels of immunoreactive atrial natriuretic peptide (irANP) during exercise in cardiac transplant patients. METHODS: Central hemodynamics, mixed expired gas and ventilatory measurements, and venous blood sampling (for irANP determination) were obtained in cardiac transplant patients at ...
Weltman A - - 1994
Ten collegiate rowers performed discontinuous incremental exercise to their tolerable limit on two occasions: once on a rowing ergometer and once on a treadmill. Ventilation and pulmonary gas exchange were monitored continuously, and blood was sampled from a venous catheter located in the back of the hand or forearm for ...
Béliveau L - - 1994
The purpose of this study was to examine atrial natriuretic peptide (ANP) secretion at rest and in response to moderate treadmill exercise (10 min, 4 km/h, 26% slope) in control dogs (n = 17) and in dogs (n = 14) with complete atrioventricular block produced by electrocauterization of the His ...
Clemson B - - 1994
To determine if peripheral angiotensin II (Ang II) prejunctional receptors facilitating NE release exist in humans, we used [3H]NE kinetic methodology to measure forearm NE spillover during intrabrachial arterial Ang II infusions in eight normal male subjects. We used the following protocol to optimize conditions for demonstrating these receptors: (a) ...
Sigurdsson A - - 1994
Static measurements of plasma neurohormones at rest may not be adequate to detect alterations in cardiovascular control mechanisms in congestive heart failure (CHF). Therefore, it is of interest to study neurohormonal activation during different physiological conditions. Plasma neurohormones were measured in 54 patients on diuretic therapy for mild or moderate ...
Robinzon B - - 1994
Cockerels with permanent cannulas in the brachial artery and vein were put into isolated slings. Arterial pressure and heart rate were continuously recorded. Following habituation, tests were initiated. In each cockerel 2 nmol/kg of the tested neurohypophysial peptide (NPs) or analogue was IV injected six times at 6-min intervals. Arginine ...
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