Search results for "Catechol"
showing 10 items of 230 documents
Formation and metabolism of catecholestrogens in depressed patients.
1990
Abstract The evidence that catecholestrogens are formed in the brain and exert behavioral effects in animal models suggests that these steroids might have psychotropic activities. In the present investigation, the formation and metabolism of catecholestrogens were studied in depressed patients. Twenty-four-hr urine samples were collected from 6 male patients (59 ± 8 years) with endogenous retarded depression (subtype primary, endogenous, and recurrent according to Research Diagnostic Criteria) and from 12 male control subjects (51 ± 4 years). The patients were treated with the monoamine oxidase inhibitor tranylcypromine (10–40 mg/day for 3–4 weeks). The concentrations of primary estrogens, …
Uptake of [3H]dopamine into dopaminergic and noradrenergic neurones of the isolated neurointermediate lobe of the rat hypophysis. Effects of desipram…
1983
The isolated neurointermediate lobe (NIL) of the rat hypophysis accumulates [3H]dopamine from the incubation medium. Column chromatographic analysis showed that 92% of the tissue radioactivity was contained in the catecholamine fraction. [3H]Dopamine represented 70% and [3H]noradrenaline 30% of the [3H]catecholamines. Desipramine (1 microM) prevented the formation of [3H]noradrenaline without affecting the storage of [3H]dopamine. Nomifensine (10 microM) blocked the storage of [3H]dopamine and [3H]noradrenaline. Thus, in the NIL, [3H]dopamine is taken up into dopaminergic and noradrenergic neurones. In the latter, [3H]dopamine is converted to [3H]noradrenaline, indicating a significant dopa…
Effects of co-administration of amitriptyline and fluoxetine on inhibitory avoidance in mice
2010
We have previously observed that, while the impairing effects of amitriptyline on inhibitory avoidance in mice are consistently observed, those of acute fluoxetine are negligible. Two experiments were designed to investigate whether a regular dose of fluoxetine potentiates the effect of a low dose of amitriptyline that is ineffective when administered alone. Male and female CD1 mice were administered i.p. 30 min before training, as follows. In the first experiment, they were injected with saline, one of three doses of amitriptyline (2.5, 5, 10 mg/kg), one dose of fluoxetine (15 mg/kg), or a combination of amitriptyline (2.5 mg/kg) and fluoxetine (15 mg/kg). In the second experiment, the mic…
Pharmacological analysis of the responsiveness of guinea-pig lung parenchymal strip to dopamine
1984
Abstract Responses to dopamine were examined in the guinea-pig isolated lung parenchymal strip. Complete cumulative concentration-response curves to dopamine exhibited a biphasic pattern with a small initial contraction at concentrations below 10(-5) M followed by a dose-dependent relaxation at higher concentrations. Phentolamine (10(-5) M) completely abolished the contractile component and enhanced sensitivity and maximal relaxation to dopamine. In the presence of phentolamine, propranolol antagonized the dopamine-induced relaxation (pA2 = 8.54 +/- 0.07). In the presence of propranolol (10(-6) M), dopamine produced a dose-related contraction displaced to the right by phentolamine. Incubati…
Effects of alterations in sympathetic nervous activity on the severity of reperfusion-induced arrhythmias in anaesthetised rats.
1987
The effects of a number of interventions influencing sympathetic nervous activity on the severity of coronary artery reperfusion-induced arrhythmias in anaesthetised rats have been examined. Noradrenaline (0.1 microgram kg-1 min-1) reduced the mortality that usually occurred as a consequence of ventricular fibrillation. Isoprenaline (5 micrograms kg-1) did not significantly affect the severity of reperfusion-induced arrhythmias, although arrhythmias occurring during the 5-min period of ischaemia were exacerbated. The alpha-adrenoceptor antagonist nicergoline (0.25 and 0.5 mg kg-1 min-1) markedly suppressed both the ventricular tachycardia and fibrillation occurring upon release of the occlu…
Evidence for noradrenaline and adrenaline as sympathetic transmitters in the chicken.
1975
1 The concentrations of noradrenaline and adrenaline in various organs, arterial plasma and venous outflow from isolated hearts of adult chickens have been determined. 2 The relative adrenaline concentrations (percentage of the sum of noradrenaline and adrenaline) in the heart (33%), spleen (16%) and brain (26%) were higher than those found in mammalian organs. Chemical sympathectomy by pretreatment with 6-hydroxydopamine caused a decrease of the noradrenaline and adrenaline concentrations in the heart to 20 and 23% and in the spleen to 16 and 29%, respectively. 3 Stimulation of the right sympathetic nerves, infusion of tyramine or infusion of a modified Tyrode solution containing 108mM K+ …
Effects of CGS 10746B on hyperactivity and place preference induced by morphine
2001
The effects of CGS 10746B, a dopamine release inhibitor, on spontaneous locomotor activity, morphine-induced hyperactivity, acquisition of conditioned place paradigm and morphine-induced conditioned place preference (CPP) was evaluated in male mice. In experiment 1, animals treated with CGS 10746B (0.5, 1, 2, 4, 8, 16, 24 and 32 mg/kg), morphine (40 mg/kg) or morphine (40 mg/kg) plus CGS 10746B (0.5, 1, 2, 4, 8, 16, 24 and 32 mg/kg) were placed in an actimeter during a period of 90 min. In experiment 2, animals treated with CGS 10746B (0.5, 1, 3 and 10 mg/kg), morphine (40 mg/kg) or morphine (40 mg/kg) plus CGS 10746B (0.5, 1, 3 and 10 mg/kg) were conditioned following a procedure unbiased …
Fuel selection during short-term submaximal treadmill exercise in the cold is not affected by pre-exercise low-intensity shivering.
2014
Exercise and shivering rely on different metabolic pathways and consequently, fuel selection. The present study examined the effects of a pre-exercise low-intensity shivering protocol on fuel selection during submaximal exercise in a cold environment. Nine male subjects exercised 4 times for 60 min at 50% (LOW) or 70% (MOD) of their peak oxygen consumption on a motorized treadmill in a climatic chamber set at 0 °C with (SHIV) and without (CON) a pre-exercise cooling protocol, inducing low-intensity shivering. Thermal, cardiorespiratory and metabolic responses were measured every 15 min whereas blood samples were collected every 30 min to assess serum nonesterified fatty acids (NEFA), glyce…
Contractile hyporesponsiveness to norepinephrine of forearm veins in chronic renal failure.
2006
Background We recently reported that endothelium-dependent relaxation is impaired in forearm veins from patients with chronic renal failure. However, assessment of responses to norepinephrine remains controversial. We examined the contractile response to norepinephrine in forearm veins from patients on chronic hemodialysis and the role of nitric oxide (NO), prostanoids, and Ca 2+ -activated K + channels in this response. Methods Isometric contraction curves were obtained in rings of forearm vein from 21 dialyzed patients and 12 multiorgan donors in response to norepinephrine (1 nmol/L to 10 μmol/L) or KCl (5 to 100 mmol/L). Results Veins from uremic patients were markedly less responsive to…
New Mussel Inspired Polydopamine-Like Silica-Based Material for Dye Adsorption
2020
A straightforward and economic procedure has been developed for the synthesis of a new polydopamine-like silica-based material that has been obtained by oxidation of catechol with KIO4 followed by reaction with 3-aminopropyltrimethoxysilane. All techniques adopted for characterization showed that the obtained material is rich in different functional groups and the morphological analyses revealed dimensions in the nanometric range. The hybrid material has been characterized by several techniques showing its polydopamine-like nature, and preliminary observations for dye adsorption have been reported.