Search results for "Dopamine"

Reply: Valproate Treatment in Schizophrenia: Interaction of GABA with Dopamine?

2004

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 …

Plasma levels and cerebrospinal fluid penetration by duloxetine in a patient with a non-fatal overdose during a suicide attempt

2009

Duloxetine is a potent and selective inhibitor of serotonin and norepinephrine reuptake with weak activity on dopamine reuptake (Wong et al. 1993). Daily doses of 60 mg are effective in the acute treatment of major depression. Duloxetine is extensively metabolized by cytochrome P450 isoenzymes (CYP) 1A2 and to a lesser extent 2D6 (Lobo et al. 2008) to numerous non-active metabolites. Maximum plasma concentration occurs after 6 h, steady-state within 3 d and the mean terminal half-life is 12 h. Fatal outcomes have been reported for acute overdoses as low as 1000 mg, and symptoms of duloxetine overdose are well described. However, information about plasma levels of duloxetine and correspondin…

Synthesis of hexahydrocyclopenta[ij]isoquinolines as a new class of dopaminergic agents.

2014

In this study, we have described the synthesis of the tricyclic 1,2,3,7,8,8a-hexahydrocyclopenta [ij]isoquinoline (HCPIQ). Herein, six differently substituted 5,6-dioxygenated-7-phenyl-HCPIQs have been synthesized using a new methodology via (E)-1-styryl-THIQ by Friedel-Crafts cyclization with Eaton's reagent. Results showed that HCPIQs (3, 3a-e) displayed a moderate affinity for D1 dopamine receptors (DR) in the micromolar range, furthermore the catecholic HCPIQs 3a (NH), 3c (NCH3) and 3e (NCH2CHCH2) exhibited outstanding affinity and high selectivity towards D2 DR. Indeed, 3a, 3c and 3e showed Ki values of 29 nM, 13 nM and 18 nM, respectively, and HCPIQs 3a (NH) and 3c (NCH3) displayed a …

Dopamine autoreceptor agonists in the treatment of schizophrenic disorders

1993

Abstract 1. Synthesis and release of dopamine as well as firing rates of dopaminergic neurons are controlled by stimulation of autoreceptors via a negative feedback regulation, investigations on therapeutic effects of autoreceptor-nonselective dopamine agonists in schizophrenia have yielded inconsistent results. 2. With respect to the dopamine hypothesis of schizophrenia, dopamine autoreceptor agonists have been tested in positive schizophrenic symptomatology in order to reduce the postulated excess of central dopaminergic activity. However, administration of selective dopamine autoreceptor agonists like talipexole or roxindole did not result in a significant improvement of psychopathologic…

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…

Selective electrochemical discrimination between dopamine and phenethylamine-derived psychotropic drugs using electrodes modified with an acyclic rec…

2010

Electrochemical discrimination between dopamine and psychotropic drugs which have in common a skeletal structure of phenethylamine, can be obtained using acyclic receptors L(1) and L(2), containing two terminal 3-alkoxy-5-nitroindazole rings. Upon attachment to graphite electrodes, L(1) and L(2) exhibit a well-defined, essentially reversible solid state electrochemistry in contact with aqueous media, based on electrolyte-assisted reduction processes involving successive cation and anion insertion/binding. As a result, a distinctive, essentially Nernstian electrochemical response is obtained for phenethylammonium ions of methamphetamine (METH), p-methoxyamphetamine (PMA), amphetamine (AMPH),…

Synthesis and photoluminescence properties of hybrid 1D core–shell structured nanocomposites based on ZnO/polydopamine

2020

In the present work, we report on the modelling of processes at the zinc oxide and polydopamine (ZnO/ PDA) interface. The PDA layer was deposited onto ZnO nanorods (NRs) via chemical bath deposition. The defect concentrations in ZnO before and after PDA deposition were calculated and analysed. The ZnONRs/PDA core–shell nanostructures were studied by transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman and Fourier-transform infrared (FTIR) spectroscopy, photoluminescence (PL) measurements, and diffuse reflectance spectroscopy. The TEM and electron energy loss spectroscopy (EELS) measurements confirmed the conformal coating of PDA, while the PL emission from ZnO and ZnONRs/P…

Effect of acetylcholine and dopamine iontophoretically applied on the sensory responsive caudate unit

1986

A putative integrative function of the striatum was evaluated through the study of the electrical activity of sensory responsive caudate neurones. Both nervous (radial nerve) and auditory stimulations were delivered in order to characterize populations of neurones affected by peripheral stimuli; the units were previously activated by iontophoretic glutamate. On these units the iontophoretic ejection of ACh and DA was tested. Experimental results demonstrated a prevalent excitatory effect of ACh, while DA appeared to exert a drastic decrease on firing rate. A comparison between peripheral stimuli and chemical substances was made. The result of such study showed a most important action of the…

The Tuberohypophyseal Dopamine System: Dopaminergic Modulation of Vasopressin Release. Characterization of Release and Metabolism of3H-Dopamine

1986

Dopamine (DA) fibres originating in the arcuate nucleus project into the neural and intermediate lobes (N-IL) of the pituitary gland. It has been shown that DA and DA agonists decrease the electrically evoked vasopressin release from the isolated N-IL, an effect antagonized by D2 selective DA antagonists (see Holzbauer et al., 1983). However, there are also observations suggesting that there is an additional facilitation of the evoked vasopressin release via D1 receptors. Thus, SKF 82526 (6-chloro-7,8-drhydroxy-1-(p-hydroxyphenyl)-2,3,4,5-tetrahydro-1H-benzazepine mesylate) concentrationdependently decreased (max. 30 % at 30 nM) and increased (max. 40 % at 3 µM) the electrically evoked vaso…