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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 ...
Valente-Mesquita V L - - 1998
Effects of hydrostatic pressure on dimeric beta-lactoglobulin A (beta-Lg) were investigated. Application of pressures of up to 3.5 kbar induced a significant red shift ( approximately 11 nm) and a 60% increase in intrinsic fluorescence emission of beta-Lg. These changes were very similar to those induced by guanidine hydrochloride, which ...
Payne S R - - 1998
This study investigated drip loss in chilled beef (hot-boned m. longissimus lumborum (LL)) under conventional packaging systems, in which a vacuum is applied, and non-vacuum packaging systems. The use of vacuum during the packaging process (vacuum packaging, CO(2) atmosphere packaging) was associated with increased drip. Drip was lower in heat-shrunk ...
Mundal H H - - 1998
Blood platelet activation in vivo was evaluated by measuring beta-thromboglobulin in plasma and high molecular weight beta-thromboglobulin in urine in hypertensive smoking and nonsmoking middle-aged men (n=36) and in normotensive age-matched controls (n=40). We found no significant linear relationships between nocturnal or resting urinary high molecular weight beta-thromboglobulin and plasma ...
Kelley G R - - 1998
The responsiveness of the heart to beta-adrenergic receptor stimulation declines with age. The aim of this study was to determine whether food restriction (FR), the most effective means of retarding the aging processes, affects the loss of beta-adrenergic responsiveness. Male Fisher 344 rats, fed either ad libitum (Group A) or ...
Pertoldi F - - 1998
Electromechanical dissociation (EMD) occurred in a 20-year-old woman 48 hours after an overdose of atenolol, despite intensive treatment of the beta-blocker poisoning (gastric lavage, charcoal, glucagon, epinephrine, atropine, correction of electrolyte abnormalities, administration of fluids, cardiac pacing, and mechanical ventilation). Administration of calcium chloride during EMD repeatedly restored blood pressure. ...
Tranfa C M - - 1998
The occurrence of cardiovascular side effects is sometimes associated with the utilization of beta-adrenoceptor agonists. The most important causes of these undesirable pharmacologic actions are as follows: (1) direct stimulation of cardiac beta-adrenoceptors; (2) reflex activation of adrenergic mechanisms due to peripheral vasodilation; (3) hypokalemia; and (4) hypoxemia. The aim ...
Hancock A A - - 1998
A-131701 (3-[2-((3aR,9bR)-cis-6-methoxy-2,3,3a,4,5,9b, hexahydro-[1H]-benz[e]isoindol-2-yl)ethyl]pyrido [3',4': 4,5]thieno[3,2-d]pyrimidine-2,4(1H,3H)-dione) is a novel compound previously shown to be selective for alpha-1a sites compared with alpha-1b adrenoceptors in radioligand binding studies and isolated tissue bioassays and to block canine urethral pressure (IUP) responses to exogenous alpha-1 adrenergic agonists to a greater extent than blood pressure responses. ...
Witte K - - 1998
The effects of amlodipine on blood pressure profiles, cardiac hypertrophy, and beta-adrenergic signal transduction were studied in transgenic hypertensive TGR(mREN2)27 rats (TGRs), which are characterized by an inverse circadian blood pressure rhythm. Cardiovascular parameters were monitored by radiotelemetry; beta-adrenoceptor density and function were measured by radioligand binding and by determination ...
van Uum S H - - 1998
The two 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) isozymes catalyze the interconversion of cortisol and cortisone. Type 1 11 beta-HSD (11 beta-HSD1) has bidirectional activity, while type 2 11 beta-HSD (11 beta-HSD2) mainly converts cortisol into cortisone. Of these two hormones only cortisol has affinity to mineralocorticoid receptors (MRs) and thus ...
Miller K E - - 1998
The class III antiarrhythmic agent, azimilide, has been shown to inhibit dihydroalprenolol binding to the beta-adrenergic receptor of rat brain and heart in an in-vitro ligand-binding assay. Azimilide, was assessed for beta-adrenergic activity, either agonist or antagonist, in the isolated perfused guinea pig heart in comparison with class III reference ...
Abdelmawla A H - - 1998
In an attempt to explore the possible involvement of venodilator beta-adrenoceptors in the constrictor response of the human dorsal hand vein to noradrenaline, we examined the ability of nadolol, a non-selective beta1/beta2-adrenoceptor antagonist, and bisoprolol a selective beta1-adrenoceptor antagonist, to potentiate the response. Twelve healthy male volunteers participated in three ...
Grover R F - - 1998
When humans ascend to high altitude (ALT) their plasma volume (PV) and total blood volume (BV) decrease during the first few days. With continued residence over several weeks, the hypoxia-induced stimulation of erythropoietin increases red cell production which tends to restore BV. Because hypoxia also activates the beta-adrenergic system, which ...
Zolk O - - 1998
1. Desensitization of the myocardial beta-adrenergic signal transduction pathway is an important mechanism which is involved in the progression of hypertensive heart disease. The aim of the present study was to evaluate the differential effects of chronic pharmacotherapy with an angiotensin converting enzyme (ACE)-inhibitor, an AT1-receptor antagonist and a direct ...
Lechat P - - 1998
Heart failure results from damage and stress to the myocardium whatever the aetiology. An increase in stress by cardiac overload is initially overcome by compensatory mechanisms that maintain blood pressure through a combination of the sympathetic nervous system and the renin-angiotensin-aldosterone system. These mechanisms may also alter myocyte function and ...
Watanabe H - - 1998
At present, the aortic pressure (Pa) waveform can only be measured invasively. In this paper, we describe a new noninvasive method of measuring Pa. The aortic diameter (Da) pulse waveform was measured noninvasively from the suprasternal fossa using an echo-tracking system that was applied to the anterior and posterior aortic ...
Love J N - - 1998
The objective of this study was to evaluate the effects of propranolol intoxication on the QT and QTc intervals in a canine model. Lead II surface electrocardiograms were retrospectively evaluated from a previous study performed in this laboratory. Thirteen pentobarbital-anesthetized and instrumented animals, after a 30-min baseline period, were given ...
Alhashemi J A - - 1998
PURPOSE: To describe a case of milrinone-associated tachycardia that was successfully treated with two beta-blockers. CLINICAL FEATURES: A 74-yr-old male patient underwent elective abdominal aortic aneurysm repair under combined epidural/general anaesthesia. He had a history of alcohol abuse, controlled hypertension and ischaemic heart disease. Postoperatively, the patient had persistent sinus ...
Hansson B G - - 1998
In summary, carvedilol lowers blood pressure effectively. There is a decrease in left ventricular mass. Carvedilol has a good metabolic profile and seems to improve insulin sensitivity. Through its effects on the endothelial function and its antioxidative properties carvedilol has positive effects on the atherosclerotic process. Carvedilol also decreases microalbuminuria. ...
Ruffolo R R RR - - 1998
Carvedilol is a third-generation vasodilating beta-blocker initially approved for the treatment of hypertension. It lowers systemic arterial blood pressure without causing reflex tachycardia and preserves renal function. More recently, carvedilol has been shown to reduce morbidity and mortality in patients with congestive heart failure. This reduction may occur in part ...
Ruffolo R R RR - - 1998
A variety of pathophysiologic processes are activated in patients with congestive heart failure (CHF), and some of these have been implicated in the progression of the disease. The most important processes to be activated in CHF are the neurohormonal systems, which include the renin-angiotensin system, the sympathetic nervous system, and ...
Feuerstein G Z - - 1997
Beta blockers have long been used in the treatment of systemic hypertension, where they effectively lower blood pressure and, in so doing, they decrease left ventricular hypertrophy. The sympathetic nervous system is activated in patients with congestive heart failure, and therefore it is logical that beta blockers may also provide ...
Mavrogiannis L - - 1997
A new pressor protein (NPP) in trypsin-activated human plasma was recently reported, whose blood pressure raising effects in bioassay rats are potentiated 300% after treatment with angiotensin I converting enzyme inhibitors (captopril). Pure NPP showed good N-terminal sequence homology with coagulation factor beta FXIIa, and little of it was present ...
McIlveen S - - 1997
1. We tested the hypothesis that the pattern and the intensity of autonomic mechanisms causing vasoconstriction in the resting bronchial circulation of awake dogs also exists in awake sheep. It was also postulated that sighing behaviour and the associated bronchovascular dilatation induced by non-adrenergic, non-cholinergic (NANC) mechanisms observed in the ...
Albrecht M - - 1997
The effects on parameters of the capillary system of the beta 1-blocker bisoprolol and of the alpha 1/beta-blocker carvedilol were investigated in 12 healthy female and 12 male non-smokers and smokers and in 20 hypertensive patients (state WHO I-II). Besides the antihypertensive and heart rate-reducing effect, carvedilol but not bisoprolol ...
Foley K O - - 1997
The effects of cardioselective beta blockade on ventilation and gas exchange were investigated in 12 male subjects with coronary artery disease during ramp treadmill testing. Patients were able to maintain much of their functional capacity as measured by oxygen consumption in the beta-blocked condition, and also maintained minute ventilation by ...
Kukin M L - - 1997
OBJECTIVE: To determine whether the acute adverse haemodynamic effects of beta blockade in patients with congestive heart failure persist during chronic treatment. DESIGN: Sequential haemodynamic evaluation of heart failure patients at baseline and after three months of continuous treatment with the beta 1 selective antagonist metoprolol. SETTING: Cardiac care unit ...
Champion H C - - 1997
Vasodilator responses to human adrenomedullin (hADM), a newly discovered hypotensive peptide, human calcitonin gene-related peptide-alpha (hCGRP-alpha) and hCGRP-beta, which share structural homology with hADM, were compared in the hindlimb vascular bed of the cat under constant flow conditions. Injections of hADM (0.003-1 nmol), hCGRP-alpha, and hCGRP-beta (0.003-0.3 nmol) into the ...
Hakamata N - - 1997
Isoproterenol was continuously administered to rats at a rate of 2.5 microg/kg/min for 7 days via subcutaneously implanted osmotic minipumps. This treatment induced cardiac hypertrophy with increases in heart rate and systolic blood pressure. Beta-adrenoceptor (beta-AR) density decreased in hypertrophied hearts, but the affinity for 125I-cyanopindolol did not change. The ...
Mazzotta G - - 1997
The pressure pain threshold of 30 patients affected by tension-type headache was assessed and the values compared with those of a group of 30 age-matched control subjects. In the patient group, pressure pain threshold values were related to the blood cell concentration of some neurotransmitters which are considered to be ...
Kirby R S - - 1997
The treatment of BPH by alpha blockade is built upon a sound anatomical, physiological and pharmacological rationale. The theory is borne out in clinical practice; alpha adrenoceptor antagonists have been shown in placebo-controlled studies to improve symptoms of BPH and increase urinary flow rate. In hypertensive patients, there is a ...
Wada T - - 1997
Physical properties of an artery can be described in terms of stiffness, distensibility, and compliance. Changes in these properties can predict atherosclerosis disease, but it is necessary to identify an index that is independent of changes in blood pressure. We measured common carotid artery diameter and pulsatile change with an ...
Jacobs M C - - 1997
In this study we examined the effects of long-term treatment of 19 patients with primary hypertension with the beta 1-adrenoceptor antagonist atenolol on norepinephrine and epinephrine kinetics, at rest and during sympathoadrenal stimulation by lower body negative pressure. Norepinephrine and epinephrine kinetics were measured by using the radioisotope-dilution technique by ...
Schmieder R E - - 1997
In hypertensive disease, the extent of target organ damage determines the prognosis. We conducted a 6-month, double-blind randomized study to compare the effects of an alpha1-adrenoreceptor blocker (bunazosin) with those of a beta1-adrenoreceptor blocker (metoprolol) on early hypertensive target organ damage at a similar level of blood pressure reduction. The ...
Suzuki M - - 1997
This study investigated the effects of chronic beta-blockade on the pathophysiology of heart failure following induction of aortic regurgitation (AR). Nine rabbits with AR were administered propranolol continuously for 7 days (AR+P), 8 rabbits with AR received vehicle for the same period (AR+C), and 7 rabbits underwent sham operation. Cardiac ...
McAuley D - - 1997
The blood pressure waveform is modified on distal propagation by phenomena such as dispersion, reflection and the state of the arterial compliance. The consequent effects are amplification and narrowing of the wave, with an increased systolic, reduced diastolic and essentially unaltered mean blood pressure. The Finapres measures the peripheral pressure ...
Poller U - - 1997
The aim of this study, carried out in six elder healthy volunteers (mean age: 61 years), was to determine the influence of muscarinic receptor blockade with atropine (15 microg/kg i.v. loading dose followed by 0.15 microg/kg/min by i.v. infusion) on the effects of i.v. infusions of noradrenaline (5 incremental doses ...
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