Search Results
Results 351 - 400 of 1169
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Silke B - - 1997
A double-blind, randomized, placebo-controlled comparison of metoprolol (50 mg) and celiprolol (200 mg) was undertaken in nine normal volunteers. Rest and exercise (supine bicycle) hemodynamics were assessed at 0, 2, 4, 6, and 8 hours following single oral doses of medication administered at weekly intervals. The influence of the ancillary ...
Mosha T C - - 1997
The alpha-carotene, beta-carotene and total provitamin A carotenoids and the effect of traditional processing practices on the retention of these provitamins were studied using amaranth, cowpea, peanut, pumpkin and sweet potato leaves. Results of this study indicated that the content of total carotenoids, beta-carotene and alpha-carotene were in the range ...
Weston A R - - 1997
Skeletal muscle buffering capacity (beta m), enzyme activities and exercise performance were measured before and after 4 weeks of high-intensity, submaximal interval training (HIT) undertaken by six well-trained competitive cyclists [mean maximal oxygen consumption (VO2max) = 66.2 ml.kg-1.min-1]. HIT replaced a portion of habitual endurance training and consisted of six ...
Perna G P - - 1997
OBJECTIVE: To determine whether the net release of beta-endorphin during exercise, similar to that of norepinephrine, is related to functional disability in patients with congestive heart failure. BACKGROUND: Plasma beta-endorphin and norepinephrine levels are elevated at rest in patients with heart failure, reflecting a functional disability. The net release of ...
Clancy R L - - 1997
To role of beta-adrenergic and muscarinic cholinergic systems on maximal treadmill exercise performance and systemic O2 transport during hypoxic exercise (PIO2 approximately 70 Torr) was studied in rats acclimatized to hypobaric hypoxia (PIO2 approximately 70 Torr for 3 weeks, A rats) and in non-acclimatized littermates (NA rats). Untreated A rats ...
Lipworth B J - - 1997
A partial beta-adrenoceptor (beta-AR) agonist will exhibit opposite agonist and antagonist activity depending on the prevailing degree of adrenergic tone or the presence of a beta-AR agonist with higher intrinsic activity. In vivo partial beta-AR agonist activity will be evident at rest with low endogenous adrenergic tone, as for example ...
Ishida K - - 1997
To elucidate whether combined adrenergic and parasympathetic blockade would affect the ventilatory response to exercise, especially at the initial stage (phase I), six healthy subjects performed a brief and light voluntary bilateral leg extension exercise and passive movements under the conditions of control (before the blockade) and after intravenous administration ...
Travis M D - - 1996
We examined the effects of the L- and D-isomers of S-nitroso-beta,beta-dimethylcysteine (L- and D-S-nitrosopenicillamine, 10(-7)-10(-5) M) on the guanosine 3',5'-cyclic monophosphate (cGMP) content of cultured porcine aortic smooth muscle cells and the decomposition of these stereoisomers to nitric oxide (NO). L-S-nitrosopenicillamine was a more potent generator of cGMP than D-S-nitrosopenicillamine ...
Raven P W - - 1996
The increased ratio of 5 alpha to 5 beta reduced steroids associated with apparent mineralocorticoid excess (AME) may be a necessary consequence of altered 11 beta-hydroxysteroid dehydrogenase (11-HSD) activity. In order to test this hypothesis we have compared changes in 11-HSD activity and 5 alpha/5 beta reduction in a variety ...
Franceschini R - - 1996
In order to obtain data regarding peripheral levels of beta-endorphin in head pain syndromes, we evaluated the plasma beta-endorphin secretory pattern in 12 adult male patients suffering from cluster headache. Blood samples were drawn every 2 hours for a 24-hour period, and in addition at 30-minute intervals for 120 minutes ...
Fujii N - - 1996
This study was undertaken to clarify whether beta-adrenergic receptor (beta-AR) translocation from intracellular sites to the cell surface contributes to an increase in the number of beta-AR in lymphocytes from trained and untrained men after exercise. Nine trained and 9 untrained subjects performed exercise on a bicycle ergometer until exhaustion. ...
Head A - - 1996
OBJECTIVE: To measure the previously reported beta blocker induced adverse changes in mood state and anxiety measures, and to determine if prolonged aerobic exercise attenuates such mood modifications. METHODS: After 4 days of drug treatment with comparable doses of propranolol (40 and 80 mg), metoprolol (50 and 100 mg), or ...
Mäki T - - 1996
In order to evaluate the effect of beta-blocking agents with and without intrinsic sympathomimetic activity (ISA) on work efficiency in healthy subjects, we studied the haemodynamic and gas exchange parameters, as well as blood lactate concentrations, during a graded maximal bicycle exercise test performed after perorally given propranolol (PRO) and ...
Hellström L - - 1996
Gender differences in adrenergic regulation of glycerol levels in subcutaneous, abdominal adipose tissue were investigated during submaximal exercise in non-obese, healthy men and women, using microdialysis. During exercise, glycerol levels in venous plasma and venous serum concentrations of free fatty acids increased more in women and reached about two-fold higher ...
Cosenzi A - - 1996
Endothelins (ET) are recently discovered vasoconstrictor agents released from endothelial cells and have been the object of intense investigation by researchers. Many of the factors that seem to influence the release of ET are modified by prolonged exercise. The purpose of this study was to investigate the effect of physical ...
Signore P E - - 1996
Neural control of the cardiac responses to exercise in air (running) and under water (diving) was studied in the muskrat (Ondatra zibethicus) by means of acute pharmacological blockade with the muscarinic blocker atropine and the beta-adrenergic blocker nadolol. Saline injection was used as a control. Controls running on a treadmill ...
Gonzales F - - 1996
The influence of age, physical conditioning and physical exercise on platelet function on human being is still controversial. The aim of our study were to evaluate the effect of physical exercise on platelet activation measured by beta-thromboglobulin (beta-TG) levels and the number of platelets in sedentary and athlete subjects of ...
Nieto J L - - 1996
Adaptive changes in the beta-adrenergic adenylyl cyclase (AC) system in response to endurance training were studied in heart and adipose tissue. Training was performed by making male Wistar rats run on a motor-driven treadmill. The changes following exercise training were opposite in the two tissue studied. The density of beta-adrenergic ...
Yao B - - 1996
AIM: To study the effects of M1 and M2 receptor agonists and blockers on dog respiration. METHODS: Using thoracic respiratory transducer and RM-86 multipurpose polygraph to determine respiratory rate (RR), tidal volume (TV), and minute ventilation volume (MVV), and DH-100G blood gas analysis instrument to analyze pO2, pCO2 and pH. ...
Kapoor C - - 1996
OBJECTIVES: Vascular responsiveness to infusions of vasoactive substances varies between ethnic groups. Indians of Asian origin are a rapidly growing ethnic group in the United States but have not been extensively studied. We sought to determine whether there was any difference in venous responsiveness to a local infusion of vasoactive ...
Ryan D M - - 1996
Catecholamines restore cardiac contraction depressed by hyperkalaemia (raised [K+]O) and acidosis, yet in exercise hyperkalaemia and acidosis are tolerated during beta adrenergic blockade. To test whether the negative effects of raised [K+]O are offset by a non-adrenergic hormone, angiotensin II (AII) was given to rabbit papillary muscle (All 75 nM, ...
Hampton J R - - 1996
There are good theoretical reasons for supposing that long-term treatment with a beta-blocker would improve symptoms and survival in patients with heart failure. A series of small studies have shown that beta-blockers improve haemodynamic parameters, but it is well known that these correlate poorly with symptoms. There is some evidence ...
Raulo S M - - 1996
The activities of lysosomal enzymes, such as beta-glucuronidase and N-acetyl-beta-D-glucosaminidase, have been shown to increase in muscle after endurance exercise. We examined whether measurable activities of lysosomal enzymes are present in equine plasma and whether the exercise-induced changes in the muscle are reflected in plasma. Six trained Standardbred trotters performed ...
Liss S - - 1996
The results of stimulating human subjects with the LISS Cranial Stimulator (LCS) and the LISS Body Stimulator (LBS) include an increase or decrease in the activities of certain neurotransmitters and neurohormones and the reduction of associated pain, insomnia, depression, and spasticity. The effects were documented in human subjects with measurements ...
Eston R - - 1996
The ratings of perceived exertion (RPE) scale has received widespread acceptance for gaining a subjective estimate of work intensity and as a means of monitoring and regulating exercise intensity across a variety of populations. The original premise for the use of the scale was its high correlation with heart rate ...
Koizumi T - - 1996
We have previously shown in sheep that pulmonary vascular resistance decreases rapidly after the onset of constant exercise, followed by a slower and smaller second vasodilation. The second phase is partly regulated by alpha- and beta-adrenoceptor activation. We examined the effect of inhaled nitric oxide (NO; 40 ppm) and intravenous ...
Hallén J - - 1996
Onset of exercise leads to a sudden increase in [K+] in venous plasma from the exercising muscles. Delayed by about 10 s. the arterial [K+] rises nearly at the same rate as the venous concentration. At exercise intensities below 100% of Vo2max, both venous and arterial [K+] stabilize at a ...
Cui Y - - 1996
State-dependent changes in extracellular concentration of endogenous opioids in the septum of Columbian ground squirrels were examined in the hibernating and euthermic states using in vivo microdialysis. The order of estimated extracellular concentration was found to be: hibernating > interbout euthermia > non-hibernating euthermia for dynorphin A and interbout euthermia ...
Eysmann S B - - 1996
To examine whether beta-adrenergic desensitization occurs after prolonged exercise, echocardiograms, heart rate responses to isoproterenol, plasma catecholamines, and circulating lymphocyte beta-adrenergic receptors were examined in 10 sedentary normal subjects at rest and after brief (10 min) and exhaustive (mean duration 95 min) cycle exercise. Resting end-diastolic volume and ejection fraction ...
Kuhn W - - 1996
Death of dopaminergic neurons in Parkinson's disease (PD) may partially be caused by synthesis and accumulation of endogenous and exogenous toxins. Because of structural similarity to MPTP, beta-carbolines, like norharman and harman, have been proposed as putative neurotoxins. In vivo they may easily be formed by cyclization of indoleamines with ...
Dicker A - - 1996
The ability of different adrenergic agents to stimulate nonshivering thermogenesis in Syrian hamsters was investigated. The hamsters were cold-acclimated to 6 degrees C and their thermogenic response was investigated in an open-circuit system at 24 degrees C. Both norepinephrine and the beta 3-specific adrenergic agonist CGP-12177 induced a high rate ...
Brodsky M A - - 1996
To further define the relation between changing adrenergic tone, beta-blocker therapy, and clinical ventricular tachycardia (VT), we evaluated these factors in 35 patients with VT unrelated to coronary artery disease or ventricular dysfunction. Testing included Holter monitoring (91% had VT), exercise test (69% had VT), Adrenergic responsiveness of VT was ...
Stoschitzky K - - 1996
OBJECTIVE: We recently reported a highly stereoselective increase in plasma concentrations of (S)-atenolol during exercise which is most likely due to a release of the drug from adrenergic cells. The objective of the present study was to investigate the influence of physical exercise on plasma concentrations of the (R)- and ...
Chugh L K - - 1996
Growth of embryonic axis of germinating pea seeds (Pisum sativum cv. Bonneville) was significantly inhibited by as low as 0.25 mM cadmium and the elongation of the radicle was affected more severely than that of the plumule. Total amylolytic activity, as well as activities of alpha- and beta-amylases, diminished progressively ...
Malerba M - - 1996
The effects on exercise tolerance after acute administration of beta 2-agonists were investigated in 11 patients with partly reversible chronic airway obstruction after 400 micrograms of salbutamol (S) given intravenously (i.v.) and after 400 micrograms i.v. of a new selective beta 2-agonist, broxaterol (B), by a cardiopulmonary incremental exercise test. ...
Gullestad L - - 1996
1. Variable results have been reported on the effect of beta-adrenoceptor blockers on maximal oxygen uptake (VO2 max) and exercise endurance. This may in part be due to different subject populations, but it could also be due to an adaption of metabolic and haemodynamic responses to exercise during chronic treatment ...
Kantola I - - 1996
Changes in the release of atrial natriuretic peptide (ANP) and vasopressin (VP) may contribute to the final outcome of beta-adrenoceptor blocking therapy. Therefore, we administered 2 hours before a bicycle exercise test (a 30-minute exercise with 100 W work load) in a randomized, double-blind, placebo-controlled crossover study orally 50 mg ...
Matthys D - - 1996
The aim of this study was to assess plasma ammonia levels during acute treadmill exercise in dogs after intravenous administration of a single dose of different cardioselective (atenolol) and non-selective (sotalol and propranolol) beta-adrenergic blocking drugs. The experiments were performed on 6 male mongrel dogs (20-25 kg) trained to run ...
Tuininga Y S - - 1995
BACKGROUND: Physical exercise and mental work cause alterations in cardiac autonomic control. beta-Blockers protect the heart against stress, and this effect may be in part centrally mediated. In this context, the lipophilicity of the drug would be clinically relevant. METHODS AND RESULTS: Thirty postinfarct patients were randomized to receive 100 ...
White M - - 1995
The effect of beta-adrenergic receptor downregulation on peak exercise response in patients with heart failure has not been directly investigated. Seventy-two patients with idiopathic dilated cardiomyopathy who had a mean ejection fraction of 23 +/- 1% (mean +/- SEM) and New York Heart Association class II or III symptoms were ...
Madjlessi-Simon T - - 1995
The purpose of this trial was to study the additional anti-ischaemic effects of amlodipine in coronary patients with ambulant ischaemia despite beta-blocker therapy. Beta-blockers are the most effective drug therapy for reducing the frequency and duration of ambulatory ischaemic episodes. However, the therapeutic advantage of combined calcium antagonist-beta-blocker treatment remains ...
Schneider D A - - 1995
The purpose of the present study was to examine the relationship between minute ventilation (VE) and plasma concentrations of epinephrine (EPI) and norepinephrine (NE) during incremental cycling (20 W.2 min-1) performed under conditions of beta-adrenergic blockade (80 mg of propranolol) and placebo in six untrained male subjects. No significant differences ...
Holubarsch C - - 1995
BACKGROUND: DL-Sotalol has class III antiarrhythmic activity through prolongation of the repolarization phase of the action potential as well as beta-adrenoceptor-blocking properties. Although the former effect was found to exert positive inotropic effects in animal experimental studies, the latter may be detrimental in heart failure due to negative inotropism. In ...
Thompson J M - - 1995
Dopamine-beta-hydroxylase (D beta H) is the enzyme responsible for intraneural conversion of dopamine to norepinephrine. Its deficiency results in failure of norepinephrine synthesis, excessive dopamine release and orthostatic hypotension. We studied a young patient with this deficiency using the currently available methods to assess sympathetic function namely measurement of norepinephrine ...
Benthem L - - 1995
The influence of 48 hours of starvation on sympathoadrenal regulation of nutrient utilization was investigated in rats. To assess the role of alpha- and beta-adrenoceptors, rats were studied during alpha- and beta-blockade. Energy metabolism was measured using indirect calorimetry before, during, and after moderate swimming exercise (approximately 60% maximal O2 ...
Schrauwen P - - 1995
beta-Adrenoceptor blocking agents impair endurance exercise performance in healthy subjects and in patients with hypertension. A possible explanation for the reduced exercise tolerance is a diminished availability of plasma non-esterified fatty acids (NEFA) for energy production during exercise. This study investigated the effect of beta-adrenoceptor blockade on NEFA uptake of ...
Patel J J - - 1995
OBJECTIVES: This study was designed to assess the effects of beta-blockade on cardiopulmonary exercise performance in symptomatic patients with tight mitral stenosis in sinus rhythm. BACKGROUND: The role of beta-blockers in these patients has been controversial and assessment of effort tolerance using treadmill exercise time has produced conflicting results. METHODS: ...
Matthys D - - 1995
The purpose of the present study was to document exercise induced hyperammoniemia after blockade of the beta-adrenoceptors and to investigate the effect of administration of branched-chain amino acids (BCAA) and glucose in these conditions. Seven dogs, chronically instrumented with a catheter in the deep jugular vein and a Doppler probe ...
Pennacchio M - - 1995
An aqueous extract obtained from the leaves of the traditional Aboriginal medicinal plant Eremophila alternifolia R.Br. (Myoporaceae) was tested on isolated hearts of normotensive rats using the Langendorff heart preparation. A single injection of the extract into the retrograge perfusion solution induced cardioactivity, consisting of a short initial increase in ...
Epple H J - - 1995
In vivo electrogenic Na+ absorption (JeNa) in the human rectum is controlled by acute variation of aldosterone in nanomolar concentration range. In this study we report both the induction of JeNa in human rectum epithelium by nanomolar aldosterone added in vitro and the enzymatic control of glucocorticoid action on JeNa. ...
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