Search results for "Dopamine antagonist"
showing 10 items of 66 documents
Serotonin-dopamine interaction: electrophysiological evidence.
2008
In this review, the most relevant data regarding serotonin (5-hydroxytryptamine, 5-HT)/dopamine (DA) interaction in the brain, as studied by both in vivo and in vitro electrophysiological methods, are reported and discussed. The bulk of neuroanatomical data available clearly indicate that DA-containing neurons in the brain receive a prominent innervation from 5-HT originating in the raphe nuclei of the brainstem. Furthermore, this modulation seems to be reciprocal; DA neurons innervate the raphe nuclei and exert a tonic excitatory effect on them. Compelling electrophysiological data show that 5-HT can exert complex effects on the electrical activity of midbrain DA neurons mediated by the va…
Heart rate variability during sleep in patients with schizophrenia treated with olanzapine.
2004
Cardiac adverse events in patients treated with atypical antipsychotics have gained increasing interest in recent years. In the present study, heart rate variability (HRV), which is a sensitive parameter reflecting central autonomic cardiac control, was investigated during treatment with olanzapine. Ten physically healthy male patients with schizophrenia, who displayed predominantly negative symptoms, were studied in the sleep laboratory under drug-free baseline conditions and after 4 weeks of olanzapine medication. HRV was assessed during different sleep stages both in the time and frequency domains. Only slight changes in HRV were shown during treatment, and appeared to be independent of …
Fluvoxamine augmentation of olanzapine in chronic schizophrenia: pharmacokinetic interactions and clinical effects.
2002
Olanzapine is a substrate of the cytochrome P450 enzyme (CYP) 1A2. In this study, pharmacokinetic interactions and clinical effects of adding the CYP1A2 inhibitor fluvoxamine to steady-state olanzapine was examined in patients suffering from schizophrenia. Eight patients had been treated for at least 3 months with 10 to 20 mg/day olanzapine. Fluvoxamine (100 mg/day) was added (week 0) to the olanzapine treatment and continued for 8 weeks. Concentrations of olanzapine and its metabolite N-desmethylolanzapine and of fluvoxamine were analyzed at weeks 0, 1, 4, and 8. Addition of fluvoxamine resulted in a 12% to 112% (0.01) increase of olanzapine from 31 +/- SD 15 ng/mL (week 0) to 56 +/- 31 ng…
Nocturnal hormone profiles in patients with schizophrenia treated with olanzapine.
2005
Summary Nocturnal hormone profiles were measured in patients with schizophrenia with predominantly negative symptoms both under drug-free baseline conditions and after subchronic administration of the atypical antipsychotic olanzapine, with the aim of characterizing its pharmacological properties on the neuroendocrine level. The following hormones were studied in the sleep laboratory under polysomnographic control: adrenocorticotrophic hormone, cortisol, growth hormone (GH), prolactin, testosterone, and melatonin. Blood samples were taken at regular time intervals over the night, and serum concentrations of the hormones were determined. Ten patients completed the study, two of them were exc…
The dopamine D3 antagonist U-99194A maleate increases social behaviors of isolation-induced aggressive male mice.
1999
Rationale: Blockade of D1/D2 dopamine receptors produce an antiaggressive action commonly associated with an impairment of other motor behaviors. The D3 receptor seems to present opposite actions to the D1 and D2, since the blockade of this receptor produces stimulation of motor activity which has been associated with an increase in dopamine neurotransmission. Objective: In this work, the action of the dopamine D3 antagonist U-99194a maleate on locomotor activity and in a social interaction test in male mice was evaluated. Methods: Animals isolated during 30 days were treated with U-99194a maleate (20–40 mg/kg) or saline and locomotor activity was measured 20 min after drug administration. …
Head-twitch and forepaw-shake responses after single and repeated treatment with rolipram: interaction with noradrenergic and dopaminergic agonists a…
1988
Dopamine D2 receptors mediate the increase in reinstatement of the conditioned rewarding effects of cocaine induced by acute social defeat
2017
Social stress modifies the activity of brain areas involved in the rewarding effects of psychostimulants, inducing neuroadaptations in the dopaminergic mesolimbic system and modifying the sensitivity of dopamine receptors. In the present study we evaluated the effect of the dopamine D1- and D2-like receptor antagonists (SCH23390 and raclopride, respectively) on the short-time effects of acute social defeat (ASD). Male OF1 mice were socially defeated before each conditioning session of the conditioned place preference (CPP) induced by 1mg/kg or 25mg/kg of cocaine plus the corresponding dopamine antagonist. A final experiment was designed to evaluate the effect of the dopamine antagonists on …
Amisulpride versus flupentixol in schizophrenia with predominantly positive symptomatology - a double-blind controlled study comparing a selective D …
1998
The benzamide amisulpride (ASP) is a selective D2-like dopamine antagonist, while flupentixol (FPX), a thioxanthene, blocks D2-like, D1-like and 5-HT2 receptors. To evaluate efficacy and safety of ASP and to investigate the importance of an additional D1-like antagonism for antipsychotic effects and extrapyramidal tolerability, a randomized double-blind multi-center study versus FPX as reference drug was performed for 6 weeks in 132 patients suffering from acute schizophrenia (DSM-III-R) with predominant positive symptomatology. Doses were initially fixed (ASP: 1000 mg/day; FPX: 25 mg/day) but could be reduced by 40% in case of side effects (mean daily doses: ASP: 956 mg; FPX: 22.6 mg). Int…
Dopamine antagonists impair ‘red-green’ discrimination in goldfish after intravitreal injection
1995
Color vision in goldfish is tetrachromatic. However, under mesopic illumination conditions the L-cones do not contribute to wavelength discrimination, and color vision becomes trichromatic. To investigate the role of dopamine in light adaptation, we tested the effect of the unspecific dopamine antagonist haloperidol and of the specific dopamine Dl receptor antagonists SCH 23390 and SKF 83566-biotinyl in behavioral wavelength discrimination experiments. After injection of dopamine antagonists into the vitreous, a reduction in wavelength discrimination was observed in the range between 560 nm and 630 nm but not in the range between 404 nm and 501 nm.
Synthesis and Dopamine Receptor Selectivity of the Benzyltetrahydroisoquinoline, (R)-(+)-nor-Roefractine
1998
(R)-(+)-nor-Roefractine (1) was synthesized by the Bischler-Napieralski route, using asymmetric reduction of the 1, 2-didehydro precursor imine with sodium (S)-N-CBZ-prolinyloxyborohydride. Compound 1 was able to displace [3H]-raclopride (a D2 dopamine receptor-selective ligand) from its specific binding sites in rat striatum with selectivity vs [3H]-SCH23390 (D1 dopamine receptor-selective ligand).