Search results for "Catechol"
showing 10 items of 230 documents
Hemodynamic effects of dobutamine in children with cardiovascular failure.
1982
The effect of dobutamine, a synthetic catecholamine, was studied in 12 patients aged one day to 14 years with low cardiac output syndromes. After initial stabilization of the patients dobutamine was administered by continuous infusion in a dosage of 7.5 or 10 μg/kg/min. Heart rate, cardiac output (using thermodilution technique and/or pulse contour method), mean systemic and mean pulmonary artery pressures were determined before and after the dobutamine infusion. Systemic and pulmonary vascular resistances, cardiac index and stroke volume index were calculated. Cardiac output and cardiac index increased significantly in every patient, whereas the heart rate changed only slightly, suggesting…
Neuronal and extraneuronal uptake and efflux of catecholamines in the isolated rabbit heart
1974
1. Isolated rabbit hearts were perfused with (−)-noradrenaline, (−)-adrenaline and (±)-isoprenaline for various time periods (1–180 min) and then washed with an amine-free medium. The venous concentration of the amine was estimated fluorimetrically during the infusion and after its end, to study removal and efflux, respectively. 2. In untreated hearts and after pretreatment with reserpine the removal had a constant rate over 20–60 min. After pretreatment with pargyline to block monoamine oxidase (MAO), however, the removal of noradrenaline declined exponentially to zero. Inhibition of the neuronal uptake (desipramine) and chemical sympathectomy (6-hydroxydopamine) abolished the removal of n…
Interrelation of peptidergic innervation with mast cells and ED1-positive cells in rat thymus
1991
The peptidergic innervation of rat thymus has been investigated by immunohistochemical methods, focusing on the spatial interrelationship of peptidergic nerve fibers with mast cells and macrophages in the rat. An antiserum directed against the protein gene product 9.5 (PGP 9.5) regarded as a pan-neuronal marker revealed a rich innervation, especially in the subcapsular cortex, in interlobular septa, and of the vasculature in the cortex and the corticomedullary boundary. A minor proportion of PGP 9.5-immunoreactive (ir) fibers supplied the thymic parenchyma. The main component of peptidergic innervation consisted of fibers costaining for tachykinins (TKs) and calcitonin gene-related peptide …
Infradian rhythms of serotonin and serotonin‐N‐acetyltransferase in the pineal gland of male rats
1983
Abstract The present investigation was carried out to determine whether in the pineal gland of male Sprague‐Dawley rats infradian rhythms with respect to serotonin, serotonin‐N‐acetyltransferase (NAT) activity, and hydroxyindole‐O‐methyltransferase (HIOMT) can be detected. The serotonin data obtained over a period of 4 weeks and subjected to power spectral analysis suggest the presence of infradian rhythms in the range of 6 and 4.3 days. NAT activity, obtained over a period of 28 days, revealed a 7‐day‐rhythm. A second peak occurring at 2.3 days remained just below the significance limit. HIOMT activity studied over a period of 8 days showed no statistically significant differences between …
Effects of dopamine in isolated rat colon strips.
2005
The aim of the present work is to investigate the effects of dopamine on isolated rat colon strips, and whether dopamine receptors are involved in these effects. Experiments on spontaneous motility and under potassium contraction were performed with dopamine and isoprenaline, both in the absence and presence of antagonists (distal colon strips, isotonic recording, Tyrode solution, 31 °C, 1 g of resting tension). At higher concentration (10–4mol/L), dopamine abolished spontaneous motility of the rat colon and this effect was not modified by antagonists. In isolated rat colon strips that were depolarized with potassium, dopamine produced concentration-dependent relaxation, without significant…
Modulatory role of a constitutively active population of α1D-adrenoceptors in conductance arteries
2002
A constitutively active population of α1D-adrenoceptors in iliac and proximal, distal, and small mesenteric rat arteries was studied. The increase in resting tone (IRT) that evidences it was observed only in iliac and proximal mesenteric and was inhibited by prazosin (pIC50 = 9.57), 5-methylurapidil (pIC50 = 7.61), and BMY 7378 (pIC50 = 8.77). Chloroethylchlonidine (100 μmol/l) did not affect IRT, but when added before the other antagonists it blocked their effect. The potency shown by BMY 7378 confirms the α1D-subtype as responsible for IRT. BMY 7378 displayed greater inhibition of adrenergic responses in iliac (pIC50 = 7.57 ± 0.11) and proximal mesenteric arteries (pIC50 = 8.05 ± 0.2) th…
Influence of Vascular Load on Plasma Endothelin-1, Cytokines and Catecholamine Levels in Essential Hypertensives
1998
In vitro studies demonstrated a relationship between ET-1 and basic Fibroblast Growth Factor (bFGF), and of bFGF with Platelet Derived Growth Factor (PDGF). The present study was carried out to investigate in vivo the behaviour after vascular stress of circulating ET-1, bFGF and PDGF, and catecholamines, and their relationship. In 12 healthy normotensives (NTs) and 15 essential hypertensives (Ehs) venous blood samples to determine circulating ET-1, bFGF and PDGF, and catecholamine (EPI and NE) levels were drawn before and at the third minute of a handgrip test. Blood pressures (BP) and heart rate were automatically recorded before starting, and at 1, 2, and 3 minutes during the test. The NT…
A 35-year effective treatment of catecholaminergic polymorphic ventricular tachycardia with propafenone
2018
Key Teaching Points • Despite proven catecholaminergic polymorphic ventricular tachycardia (CPVT) with pathogen RyR2 mutation and recurrent syncope, patients could have a favorable long-term outcome over 35 years under treatment. • Propafenone could be effective for treatment of patients with CPVT. • The beneficial effect of the monotherapy with propafenone in our patient may result from the combined antiarrhythmic effect of this drug with Na+ channel blockade and beta blocker capabilities.
Perivascular nerve fiber α-synuclein regulates contractility of mouse aorta: A link to autonomic dysfunction in Parkinson's disease
2010
Parkinson's disease and other neurodegenerative disorders associated to changes in alpha-synuclein often result in autonomic dysfunction, most of the time accompanied by abundant expression of this synaptic protein in peripheral autonomic neurons. Given that expression of alpha-synuclein in vascular elements has been previously reported, the present study was undertaken to determine whether alpha-synuclein directly participates in the regulation of vascular responsiveness. We detected by immunohistochemistry perivascular nerve fibers containing alpha-synuclein in the aorta of mice while aortic endothelial cells and muscular fibers themselves did not exhibit detectable levels of this protein…
Antiaggressive and motor effects of the DA release inhibitor CGS 10746B
2001
In the present study the effects of a wide range of doses of the dopamine release inhibitor CGS 10746B were evaluated in spontaneous activity and in aggressive behaviour using the paradigm of isolation-induced aggression. The two higher doses (8 and 16 mg/kg) produced a decrease in spontaneous motor activity. Antiaggressive effects were observed after administration of doses from 4 mg/kg upwards. At this dose, CGS 10746B diminished threat and attack, and although an increase in immobility was observed, no impairment of other motor behaviours was presented. With higher doses, aggression was practically abolished but with a concomitant effect on many other behaviours. When animals were separa…