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Nagatsu M - - 2000
BACKGROUND: It is clear that beta-blockers are effective for treatment of congestive heart failure, but their mechanism of action remains controversial. Hypothesized mechanisms include normalization of beta-receptor function and myocardial protection from the effects of catecholamines, possibly by the institution of bradycardia. We hypothesized that beta-blockade-induced bradycardia was an important ...
Anthonio R L - - 2000
In the present study, predictors of complicated initiation of beta blockade in patients with idiopathic dilated cardiomyopathy was studied. We found that generally accepted measures of severity of heart failure are not predictable, whereas low systolic blood pressure (< or =120 mm Hg) was the strongest predictor for problematic (up)titration.
Zhang Y C - - 2000
BACKGROUND: beta-Blockers are the first line of therapy for hypertension. However, they are associated with side effects because of central nervous system (CNS) effects and beta(2)-adrenergic antagonism. To overcome these problems and provide a long-term beta(1)-blockade, antisense oligonucleotides against rat beta(1)-adrenergic receptor (beta(1)-AR) mRNA (beta(1)-AS-ODN) were designed and tested for ...
Brock G - - 2000
Vasomax is an oral preparation of phentolamine mesilate (Zonagen Pharmaceuticals) currently undergoing worldwide regulatory approval for distribution. Phentolamine is primarily an alpha-adrenergic antagonist with mild sympatholytic action and a beta-adrenergic stimulating action. Over 30 years of clinical experience has shown it to be a strong direct vasodilator on muscular walled ...
Portaluppi F - - 2000
OBJECTIVE: Marked alterations have been demonstrated to occur in the platelet alpha2-adrenoceptors of patients with essential hypertension. The purpose of this study was to determine whether antihypertensive treatment with alpha-adrenergic blocker doxazosin or beta-adrenergic blocker propranolol can affect the affinity and the density of platelet alpha2-adrenoceptors in such patients. SUBJECTS ...
Shaw L - - 2000
1. The influence of 17 beta-oestradiol on pressurized isolated rat mesenteric and coronary small arteries was investigated. 2. 17 beta-oestradiol caused rapid (t1.0 < 5 mins) concentration-dependent relaxations of pre-contracted pressurized (50 mmHg) isolated rat mesenteric and coronary arteries. Similar responses were observed in both vessel types. Significant relaxations were ...
Warltier D C - - 2000
Goals for the perioperative management of patients with coronary artery disease include: * Prevent increases in sympathetic nervous system activity: reduce anxiety preoperatively; prevent stress response and release of catecholamines by appropriate use of opioids or volatile anesthetics and beta-adrenoceptor antagonists; beta-blocker therapy should be initiated before and continued during ...
Clare Zhang Y - - 2000
beta-Blockers are widely used for hypertension treatment but must be taken daily. We have developed a novel beta-blocker by targeting beta(1)-adrenergic receptor (beta(1)-AR) mRNA with antisense oligodeoxynucleotides (beta(1)-AS-ODN). A single intravenous injection of beta(1)-AS-ODN significantly reduced cardiac contractility and blood pressure (38+/-5 mm Hg, P<0.05) in spontaneously hypertensive rats for ...
Murakami M - - 2000
The objective of the present study was to evaluate the effects of a selective beta(3)-adrenoceptor agonist, (R, R)-5-[2-[[2-(3-chlorophenyl)-2-hydroxyethyl]-amino]propyl]-1, 3-benzodioxole-2,2-dicarboxylate (CL 316243), on the acutely obstructed ureter in anesthetized dogs. After a complete ureteral obstruction produced by the inflation of a balloon catheter placed within the left lower ureter, the intraluminal ...
Lindenfeld J - - 1999
To report a case of marked hypotension resulting from the concomitant use of low-dose carvedilol and intravenous dobutamine. A 54-year-old white man with severe heart failure was placed on carvedilol 3.125 mg orally twice a day; three days later the dosage was increased to 6.25 mg orally twice a day. ...
Hosseini-nia T - - 1999
Pressure-induced conformational changes in D(2)O solutions of the two genetic variants of beta-lactoglobulin A (beta-lg A) and beta-lactoglobulin B (beta-lg B) and an equal mixture of both variants (beta-lg A+B) were studied by employing variable-pressure Fourier transform infrared (VP-FTIR) spectroscopy. Changes in the secondary structure of beta-lg A were observed ...
Eno A E - - 1999
A crude extract was prepared from the roots of E. drupifera. Lethality studies in mice showed a dose-mortality relationship with an LD(50) of 145 mg/kg mice i.p. The extract (2-260 microg/kg. i.v.) was tested in graded doses on the blood pressure and heart rate of urethane anaesthetized rats. The results ...
Seljeflot I - - 1999
Elevated levels of endothelin-1 (ET-1) and von Willebrand factor (vWF), both markers indicative of endothelial function, are associated with hypertension. In a randomized open study we investigated the effect of antihypertensive treatment with the alpha-blocker doxazosin (n = 23) or the beta-blocker atenolol (n = 22) for 22 weeks on ...
Petzold T - - 1999
For the testing of heart assist devices most animal models of acute cardiac failure that are usually used show certain disadvantages. We therefore developed a new method using the beta-adrenoceptor antagonist carazolol. We administered a bolus injection of 1 mg/kg followed by a continuous infusion of 1 mg/kg/h in adult ...
Neubauer S - - 1999
Oral feeding with the creatine analogue beta-guanidinopropionate (beta-GP) reduces myocardial phosphocreatine and creatine concentrations by about 80%in vitro, this is accompanied by reduced contractile performance. We hypothesized, thus, that beta-GP feeding leads to hemodynamic changes in vivo characteristic of heart failure. beta-GP was fed to Wistar rats for up to ...
Cleophas T J - - 1999
Day-activity rhythms of heart rate and blood pressure are thought to be mediated mainly through the sympathetic nervous system and may have greater amplitudes in patients with hypertension owing to increased daytime and largely normal nighttime values. Drug-induced nighttime hypotension in patients with chronic hypertension has been associated with the ...
Cases A - - 1999
Nebivolol is a novel, potent and highly selective beta(1)-adrenergic antagonist, devoid of intrinsic sympathomimetic activity, that induces endothelium-dependent arterial and venous dilatation via the L-arginine-nitric oxide pathway. Nebivolol reduces blood pressure and peripheral vascular resistance and does not depress, but rather maintains or improves, left ventricular function in healthy subjects ...
Jarén-Galán M - - 1999
Paprika oleoresin was fractionated by extraction with supercritical carbon dioxide (SCF-CO(2)). Higher extraction volumes, increasing extraction pressures, and similarly, the use of cosolvents such as 1% ethanol or acetone resulted in higher pigment yields. Within the 2000-7000 psi range, total oleoresin yield always approached 100%. Pigments isolated at lower pressures ...
Hayreh S S - - 1999
PURPOSE: To investigate the effects of topical beta-blocker eyedrops on nocturnal arterial hypotension and heart rate and on visual field deterioration. METHODS: We prospectively investigated 275 white patients, 161 with glaucomatous optic neuropathy and 114 with nonarteritic anterior ischemic optic neuropathy, by 24-hour ambulatory blood pressure monitoring and diurnal curve ...
Wójcicki J - - 1999
The lipophilic beta-adrenoreceptor antagonist propranolol has been studied to define its pharmacokinetic and pharmacodynamic characteristics in hyperlipidemic patients. A total of 48 subjects were allocated to four study groups: (1) healthy volunteers, (2) hypercholesterolemic patients, (3) hypertriglyceridemic subjects, and (4) patients with a mixed form of hyperlipidemia. Propranolol was given ...
Erzouki H K - - 1999
The cardio-respiratory effects of cocaine were compared to various Na+ channel blocking Class I antiarrhythmics. Anesthetized rabbits were treated with various doses of either cocaine, quinidine, procainamide, lidocaine or flecainide. Cocaine produced clear decreases in blood pressure and heart rate. None of the other sodium channel blockers produced any change ...
Locker G J - - 1999
Opioids are well known to cause cardiovascular depression. The aim of the present investigation was to determine whether an interaction of opioid derivatives with catecholamines might be involved in these hemodynamic alterations. Six comatose patients were enrolled into a prospective, nonrandomized pilot trial. All patients first received a continuous i.v. ...
Roul G - - 1999
Our objective was to evaluate the effects of beta-blockers on the neurohormonal profile, particularly vasopressin (VP) release, in vasovagal syncope and to gain further insight on the pathophysiology of this syndrome. Patients (< or =75 years) with no cardiovascular, neurological disorders, or contraindications to the use of isoproterenol or beta-blockers ...
Reid J L - - 1999
There are several lines of evidence implicating increased sympathetic activity not only in the maintenance of raised blood pressure but in the pathophysiology of hypertensive complications including atherosclerosis. Beta blockers are one of the best documented classes of drugs in terms of long term safety and improvement in outcome in ...
Arendash G W - - 1999
Hypertension has been recognized as a risk factor for Alzheimer's disease (AD). Moreover, serum beta-amyloid (A beta) levels are elevated in several mutations linked to familial AD, as well as in some sporadic AD individuals. To determine the in vivo effects of A beta on blood pressure, A beta(1-40) was ...
Schmetterer L - - 1999
There is evidence that nitric oxide (NO) is involved in the chronotropic, the inotropic, and the vasodilator response to beta-adrenoceptor agonists. In the present study we hypothesized that inhibition of NO synthase may modulate the systemic vascular and cardiac effects of isoprenaline, a beta-adrenoceptor agonist, in healthy subjects. Subjects received ...
Mores N - - 1999
OBJECTIVE: The use of the decongestant pseudoephedrine has been cautioned in patients with arterial hypertension, due to the possible rise in blood pressure induced by the sympathostimulatory properties of the drug. This effect could be enhanced in hypertensives treated with beta-blockers, in whom the vasoconstrictor effect of alpha-adrenergic stimulation is ...
Schäfers R F - - 1999
In humans, prolonged administration of the beta 2-adrenoceptor agonist terbutaline leads to a desensitization of beta 2-adrenoceptor-mediated cardiovascular responses, which can be blunted by concomitant administration of the antianaphylactic drug ketotifen. This study investigated the effect of disodium cromoglycate, another antiallergic drug, on terbutaline-induced desensitization of beta-adrenoceptor-mediated cardiovascular and noncardiovascular ...
Maekawa K - - 1999
This study evaluated the effect of intravenous infusion of a non-selective alpha-adrenergic blocking agent on masseter muscle haemodynamics induced by 4 degrees C cold pressor stimulation (CPS) of the right foot and ankle, which reportedly evokes a rapidly increasing sympathetic nerve activity in human skeletal muscle. Nine healthy non-smoking males ...
Tripathi C B - - 1999
The objective of the present study was to compare the cardiovascular beta-blocking activity of two different formulations of esmolol. Spontaneously beating guinea-pig isolated atria and the heart rate and blood pressure of anaesthetized cat were employed in the study to compare the beta-blocking efficacy of the two formulations of esmolol ...
Jakubetz J - - 1999
The aim of this study was to find out whether cardiac responses to the beta-adrenoceptor antagonists with intrinsic sympathomimetic activity (ISA) xamoterol and celiprolol are mediated by cardiac beta1- or beta2-adrenoceptors or both. For this purpose we assessed, in six healthy male volunteers, the effects of xamoterol (100 and 200 ...
Shinohara K - - 1999
Pachinko is a popular form of recreation in Japan. However, in recent years, along with Pachinko's popularity, "Pachinko dependence" has become topical news. The purpose of this study was to investigate beta-endorphin, catecholamines, immune system responses and heart rate during the playing of Pachinko. The following significant results were observed. ...
Chen X - - 1999
The objective of this analysis was to determine whether changes in baroreflex sensitivity (BRS) within 35 hypertensive patients (25 M, 10 F, mean age 47 years) treated with beta-blockade as monotherapy relate to reductions in ambulatory blood pressure (BP) or its variability. BP was recorded intra-arterially directly from the brachial ...
Braakman R - - 1999
PURPOSE: Based on diameter measurements on the short posterior ciliary artery, this study was intended to determine the direct pharmacologic effect of beta-blockers; to determine the differences among a selective beta-blocker betaxolol, a beta-blocker with intrinsic sympathetic activity befunolol, and a nonselective beta-blocker timolol; and to find experimental evidence for ...
Montastruc J L - - 1999
In order to investigate the putative role of beta3-adrenoceptors in central and peripheral cardiovascular regulations, the effects of intracisternal (i.c.) and intravenous (i.v.) injections of SR 58611 A (10, 50, 100 and 200 nmol kg-1), a selective beta3-adrenoceptor agonist, were investigated in chloralose anaesthetized dogs. In normal dogs, i.v. SR ...
Bristow M R - - 1999
Hypertension is a major risk factor for the development of heart failure. Mechanisms which maintain normal function in the short term in the pressure overloaded heart have longer term deleterious effects. These include left ventricular (LV) hypertrophy and chronic activation of the adrenergic and renin-angiotensin systems. beta-Blocking agents are capable ...
Shen A Y - - 1999
1-Pyrrolidinylmethyl-2-naphthol hydrochloride (TPY-beta) has been reported to have hypotensive and bradycardiac effects in anesthetized rats. Whether administration of atropine or bilateral vagotomy affects mean arterial pressure or heart rate was examined. The percentage difference in hypotensive and bradycardiac effect of TPY-beta (0.5 mg/kg) was 63 +/- 5% and 68 +/- ...
Vischer C M - - 1999
OBJECTIVE: To investigate hemodynamic effects of thyroidectomy in horses at rest. ANIMALS: 6 healthy aged Quarter Horse mares. PROCEDURE: Horses were monitored for 5 months before and 4 weeks after thyroidectomy and for an additional 4 weeks after administration of thyroid hormone supplement (2.5 microg of thyroxine/kg of body weight, ...
de Mey C - - 1999
alpha(1)-blockers are well established for the treatment of lower urinary tract symptoms (LUTS) suggestive of benign prostatic obstruction (BPO), previously referred to as benign prostatic hyperplasia (BPH). The various available alpha(1)-blockers do not differ in terms of their clinical efficacy, but there are several indications that alpha(1)-blockers differ qualitatively with ...
Beevers D G - - 1998
Beta-blockers are not very effective at lowering blood pressure in elderly hypertensive patients or in Afro-Caribbeans and these two groups represent a large proportion of people with raised blood pressure. Furthermore they do not prevent more heart attacks than the thiazide diuretics. Beta-blockers can also be dangerous in many hypertensive ...
Liguori G A - - 1998
Sudden profound hypotensive and/or bradycardic events (HBE) have been reported in >20% of patients undergoing shoulder arthroscopy in the sitting position under interscalene block anesthesia. Retrospective studies suggest that the administration of beta-blockers is safe and may decrease the incidence of these episodes. We performed a randomized, prospective study to ...
Kawahira Y - - 1998
BACKGROUND: In the failing heart, the density and affinity of beta-adrenergic receptors in the myocardium both tend to decrease as the severity of cardiac dysfunction increases. If this suppression of beta-adrenergic receptors could be prevented or reversed, this could serve as a fundamental form of treatment for the failing heart. ...
Hayreh S S - - 1998
PURPOSE: To evaluate in rhesus monkeys parapapillary chorioretinal atrophy in chronic high-pressure glaucoma and the effects of age, atherosclerosis, and chronic arterial hypertension in a prospective, planned study. METHODS: Seventy-six eyes from 38 monkeys were studied. First, experimental atherosclerosis and chronic arterial hypertension were produced in 24 animals. Then experimental ...
Lebelt D - - 1998
The aim of the present study was to obtain information on the possible mechanisms underlying cribbing behaviour in horses. To investigate the horse's responsiveness to an external stimulus, a device for telemetric measurement of thermal threshold, using the forelimb withdrawal reflex, was developed and validated. Measurements of thermal threshold took ...
Poller U - - 1998
BACKGROUND: In patients with chronic heart failure cardiac beta 1-adrenoceptors are desensitized whereas beta 2-adrenoceptors are only marginally affected. The mechanism underlying this differential regulation is not known. OBJECTIVES: To find out whether or not human cardiac beta 2-adrenoceptors might be 'resistant' to agonist-induced desensitization and whether or not the ...
Böhm M - - 1998
Treatment with the beta-blocker carvedilol leads to an improvement of outcome and ejection fraction in heart failure. These effects occur without affecting the number of beta-adrenergic receptors, as determined in right ventricular biopsies from patients with heart failure. This study was aimed at investigating the effects of carvedilol on beta-adrenergic ...
Millgård J - - 1998
Several studies indicated an abnormal endothelium-dependent vasodilation (EDV) in hypertensive patients, but no study has systematically investigated the effects of different pharmacologic classes of antihypertensive drugs on EDV. This study aimed to evaluate the effects of three different antihypertensive regimens [angiotensin-converting enzyme (ACE) inhibition, calcium channel blockade, and beta-blockade] on ...
Whalen E J - - 1998
The aim of this study was to determine whether the blockade of beta-adrenoceptors would enhance cAMP-mediated signal transduction processes in vivo. The administration of the membrane permeable cAMP analogue, 8-(4-chlorophenylthiol)-cAMP (8-CPT-cAMP, 10 micromol/kg, i.v.) produced an increase in heart rate (+27 +/- 2%, P < 0.05), a fall in mean ...
Grossman E - - 1998
Hypertensive crisis is defined as a severe elevation in BP and is classified as either urgency or emergency. In hypertensive urgency there is no end-organ injury and no evidence that acute BP lowering is beneficial. Indeed, rapid uncontrolled pressure reduction may be harmful. Therefore, in hypertensive urgencies BP should be ...
Pitzalis M V - - 1998
STUDY OBJECTIVE: The results of studies on the effect of beta-adrenergic blockade on respiratory sinus arrhythmia (RSA) are discordant. The aim of this study was to verify whether chronic beta-adrenergic blockade is capable of increasing RSA, and therefore vagal outflow, and to analyze whether the mechanism of action is central ...
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