Search results for "Azepines"
showing 10 items of 135 documents
Hippocampal dopamine receptors modulate the motor activation and the increase in dopamine levels in the rat nucleus accumbens evoked by chemical stim…
2005
A number of studies have shown that chemical stimulation (using N-methyl-D-aspartate (NMDA) infusions) or electrical stimulation of the ventral hippocampus (VH) elicits locomotor activation and sustained increases in nucleus accumbens (NAc) dopamine (DA) levels in rodents. How DA neurotransmission in NAc is involved in these effects has also been well established. However, the modulatory role of the DA receptors located in VH is not yet fully understood. The purpose of this study was to characterize the role played by VH D1 and D2 subtype receptors in both the locomotor activation and NAc DA increases induced by NMDA stimulation of the VH. This was assessed by studying how retrodialysis app…
Hippocampal dopamine receptors modulate cFos expression in the rat nucleus accumbens evoked by chemical stimulation of the ventral hippocampus
2005
Recently, we have shown that D1 and D2 receptors in the ventral hippocampus (VH) modulate both the locomotor activation and the increase in dopamine (DA) levels in the rat nucleus accumbens (NAc) induced by NMDA stimulation of the VH. In the present study we analyze the possible role of VH D1 and D2 receptors in the modulation of the cFos expression in NAc (core and shell subregions) and in dorsal striatum. This was assessed by immunohistochemical analysis of cFos expression in the rat brains after retro-dialysis application of NMDA (50mM, 10 min) into VH, in absence and in presence of either the D1/D5 receptor antagonist SCH 23390 (100 and 250 microM, 60 min) or the D2 receptor antagonist …
Pharmacological characterisation of a new model of antigen-induced pulmonary late-phase reaction in the conscious guinea pig which uses additional po…
1996
The aim of the present study was to develop a new model of allergic late-phase reaction in the airways of conscious guinea pigs (GPs) and to characterise it by pharmacological intervention. GPs were pretreated with cyclophosphamide and sensitized with ovalbumin (OA) in Al(OH)3. Weekly inhalations of polymyxin B were performed before and during sensitization and continued throughout the study period. Under cover of 10 mg/kg i.p. mepyramine all GPs still exhibited a pronounced immediate reaction (IR), peaking during the first 15 min after OA. Nine out of 15 GPs demonstrated, during screening, a reproducible (twice) second phase (late phase reaction (LPR)] of decreased airflow and tidal volume…
Peripheral benzodiazepine binding sites on striated muscles of the rat: Properties and effect of denervation
1985
In order to test the hypothesis that peripheral benzodiazepine binding sites mediate some direct effects of benzodiazepines on striated muscles, the properties of specific 3H-Ro 5-4864 binding to rat biceps and rat diaphragm homogenates were investigated. In both tissues a single population of sites was found with a KD value of 3 nmol/l. The density of these sites in both muscles was higher than the density in rat brain, but was considerably lower than in rat kidney. Competition experiments indicate a substrate specificity of specific 3H-Ro 5-4864 binding similar to the properties already demonstrated for the specific binding of this ligand to peripheral benzodiazepine binding sites in many…
Impact of ''off-label'' use of ivabradine on exercise capacity, gas exchange, functional class, quality of life, and neurohormonal modulation in pati…
2010
Background: Epidemiologic studies indicate that elevated heart rate (HR) is an independent risk factor for mortality and morbidity in patients (pts) with chronic heart failure (CHF). Clinical trials with b-blockers suggest that HR reduction is an important mechanism of their benefit in pts with stable CHF. Pharmacologic inhibition of the If current now provides the opportunity of pure HR reduction. The purpose of this study was to evaluate the impact of ‘‘Off-Label’’ use of ivabradine on exercise capacity, gas exchange, functional class, quality of life, and neurohormonal modulation in pts with ischemic CHF. Methods: Between January 2008 and June 2008, a graded maximal exercise test with re…
Effects of two selective dopaminergic antagonists on ethologically-assessed encounters in male mice
1993
Abstract 1. Although it is accepted that dopaminergic antagonists suppress aggressive behaviour, the drugs used have been relatively non-selective or specific to the D2 receptor. 2. The selective D1 antagonist, SCH 23390, makes it possible to evaluate the impact of this receptor on aggressive behaviour. 3. The effects of SCH 23390 and Spiperone (a D2 antagonist) on the aggressive behaviour of mice were assessed employing a “standard opponent” test. 4. Both drugs markedly decreased aggressive behaviour whilst increasing immobility. However, whilst SCH 23390 increased immobility to a small extent, Spiperone, produced a general decline in active behaviours. 5. It appears that the D1 receptor i…
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 …
Action of the racemate and the isomers of the platelet-activating factor antagonist bepafant (WEB 2170) after oral administration to guinea-pigs and …
1991
The aim of the present study was to clarify whether there is a difference in terms of potency and pharmacodynamic half time between the isomers and the racemate of the platelet-activating factor antagonist WEB 2170 (bepafant) after oral administration to guineapigs or rats. The following experiments were performed in the guinea-pig. Infusion of platelet-activating factor at 30 ng/ (kg × min) for 30 min to anaesthetized guinea-pigs induced a decrease of respiratory flow and mean arterial blood pressure. Oral pretreatment with WEB 2170 or isomers, respectively, 60 min before infusion of plateletactivating factor inhibited these changes in a dose-dependent manner. The ED50S for inhibition of r…
Comparison of Ivabradine Versus Metoprolol in Early Phases of Reperfused Anterior Myocardial Infarction With Impaired Left Ventricular Function: Prel…
2009
BACKGROUND: beta-blockers in ST-segment elevation myocardial infarction (STEMI) are indicated for patients without a contraindication, particularly in patients with high heart rates (HR) or blood pressures. Epidemiological studies have shown that elevated HR represents a risk factor for cardiovascular morbidity. The study investigates the feasibility, tolerability, and the effects after 30 days of follow-up of ivabradine (IVA) versus metoprolol (METO) in early phases of anterior STEMI reperfused by percutaneous coronary intervention (PCI). METHODS AND RESULTS: Patients with a first anterior STEMI, Killip class I-II, an acceptable echocardiographic window, and admitted within 4hours of the o…
Effects of endotoxin on neurally-mediated gastric acid secretion in the rat.
1998
Abstract The effects of a peripheral administration of E. coli endotoxin on neurally-mediated gastric acid secretion and the role of endogenous opioids or PAF receptors in endotoxin effects have been evaluated in the continuously perfused stomach of the anaesthetized rat. Gastric acid secretion stimulated by distension (20 cm H2O) was reduced dose-dependently by single intravenous bolus injection of endotoxin (0.1–10 μg kg−1). Doses of 5 μg kg−1 induced a peak reduction of distension-stimulated acid output and significantly reduced the secretory response induced by an intravenous bolus of 2-deoxy-d-glucose (150 mg kg−1). This dose of endotoxin did not significantly modify mean systemic arte…