Search results for "Dopamine Antagonists"
showing 10 items of 44 documents
Brain histamine depletion enhances the behavioural sequences complexity of mice tested in the open-field: Partial reversal effect of the dopamine D2/…
2017
Markers of histaminergic dysregulation were found in several neuropsychiatric disorders characterized by repetitive behaviours, thoughts and stereotypies. We analysed the effect of acute histamine depletion by means of i. c.v. injections of alpha-fluoromethylhistidine, a blocker of histidine decarboxylase, on the temporal organization of motor sequences of CD1 mice behaviour in the open-field test. An ethogram encompassing 9 behavioural components was employed. Durations and frequencies were only slightly affected by treatments. However, as revealed by multivariate t-pattern analysis, histamine depletion was associated with a striking increase in the number of behavioural patterns. We found…
[123I]IBZM SPECT in patients treated with typical and atypical neuroleptics: relationship to drug plasma levels and extrapyramidal side effects
1997
[123I]Iodobenzamide (IBZM) is an iodine-labeled dopamine receptor ligand and can be used to visualize brain D2 receptors in humans with single photon emission computerized tomography (SPECT). The ratio of striatal IBZM uptake to uptake in frontal cortex (ST/FC ratio) represents a semiquantitative measure of D2 receptor binding in the striatum. Our study sample included six patients treated with haloperidol (3.0-8.0 mg/day orally; one patient with an average of 0.9 mg/day intramuscularly), five patients with benperidol (9.0-15.0 mg/day orally) and nine patients treated with clozapine (200.0-600.0 mg/day orally). Typical neuroleptics (TNs) and atypical neuroleptics (ANs) were significantly di…
Baseline [18F]-FDOPA kinetics are predictive of haloperidol-induced changes in dopamine turnover and cognitive performance: A positron emission tomog…
2007
The telencephalic dopamine innervations contribute to the modulation of cognitive processing. However, the relationship between cognitive effects of D(2/3)-receptor antagonism and dopamine transmission is not described in healthy subjects. We therefore tested effects of acute haloperidol (5 mg/d over 3 days) on continuous performance task (CPT) performance and 6-[(18)F]-fluoro-l-DOPA (FDOPA) PET parameters. Nine physically and mentally healthy male men performed two FDOPA-PET scans including arterial plasma withdrawal. Over 3 days before the second scan, all subjects were treated with 5 mg/d haloperidol orally. Using our novel steady-state analysis, we calculated the intrinsic rate of the c…
Striatal and extrastriatal D2/D3-receptor-binding properties of ziprasidone: a positron emission tomography study with [18F]Fallypride and [11C]raclo…
2008
To elucidate the Batypicality( of ziprasidone, its striatal and extrastriatal D2/D3-receptor binding was characterized in patients with schizophrenia under steady-state conditions. These data were compared with striatal receptor occupancy values after single-dose ziprasidone ingestion in healthy controls. ( 18 F)fallypride positron emission tomography (PET) recordings were obtained in 15 patients under steady-state ziprasidone treatment at varying time points after the last dose. Binding potentials were calculated for striatal and extrastriatal regions. D2/D3-receptor occupancies were expressed relative to binding potentials in 8 unmedicated patients. In a parallel ( 11 C)raclopride-PET stu…
Stratified Care vs Step Care Strategies for Migraine
2000
ContextVarious guidelines recommend different strategies for selecting and sequencing acute treatments for migraine. In step care, treatment is escalated after first-line medications fail. In stratified care, initial treatment is based on measurement of the severity of illness or other factors. These strategies for migraine have not been rigorously evaluated.ObjectiveTo compare the clinical benefits of 3 strategies: stratified care, step care within attacks, and step care across attacks, among patients with migraine.Design and SettingRandomized, controlled, parallel-group clinical trial conducted by the Disability in Strategies Study group from December 1997 to March 1999 in 88 clinical cen…
Prolactin plasma levels and D2-dopamine receptor occupancy measured with IBZM-SPECT
1996
By the application of 123([123I]IBZM), an iodine-labelled dopamine D2-receptor antagonist, brain D2 receptors in humans can be visualized with single photon emission computed tomography (SPECT). The ratio of IBZM binding to striatal regions versus binding to frontal cortex (ST/FC ratio) provided a semiquantitative measurement of D2 receptor binding in the striatum. This study investigated the relationship between receptor occupancy and plasma prolactin levels in 12 male patients treated with haloperidol, benperidol or clozapine. Prolactin levels were positively correlated with D2 receptor occupancy, reflecting at least in part a comparable dopamine receptor antagonism in different dopaminer…
In vitro P-glycoprotein efflux inhibition by atypical antipsychotics is in vivo nicely reflected by pharmacodynamic but less by pharmacokinetic chang…
2011
Abstract Background P-glycoprotein (P-gp), an efflux transporter of the blood–brain barrier, limits the access of multiple xenobiotics to the central nervous system (CNS). Thus drug-dependent inhibition, induction or genetic variation of P-gp impacts drug therapy. Methods We investigated atypical antipsychotics and their interaction with P-gp. Amisulpride, clozapine, N-desmethylclozapine, olanzapine, and quetiapine were assessed in vitro on their inhibitory potential and in vivo on their disposition in mouse serum and brain, and behaviourally on the RotaRod test. In vivo wildtype (WT) and mdr1a/1b double knockout mice (mdr1a/1b (−/−, −/−); KO) were investigated. Results In rhodamine 123 eff…
Preclinical evidence of new opioid modulators for the treatment of addiction.
2010
Addiction to opiates is one of the most severe forms of substance dependence, and despite a variety of pharmacological approaches to treat it, relapse is observed in a high percentage of subjects. New pharmacological compounds are necessary to improve the outcome of treatments and reduce adverse side effects. Moreover, drugs that act on the opioid system can also be of benefit in the treatment of alcohol or cocaine addiction. AREA COVERED BY THIS REVIEW: Recent preclinical studies of pharmacological agents for the treatment of opiate addiction (2008 to the present date).The reader will be informed of the latest drugs shown in animal models to modify dependence on opiates and the reinforcing…
Diagnosis and therapeutic management of primary headache in an emergency setting
2013
Anti-anhedonic actions of the novel serotonergic agent flibanserin, a potential rapidly-acting antidepressant
1998
Chronic exposure to mild unpredictable stress has previously been found to depress the consumption of palatable sweet solutions and to block the formation of conditioned place preferences; these effects are reversed by chronic treatment with tricyclic or atypical antidepressant drugs. The present study was designed to evaluate the antidepressant-like activity in this model of flibaserin (BIMT-17), a novel serotonergic agent with 5-HT1A receptor agonist and 5-HT2 receptor antagonist properties. Two experiments were conducted, using rats (experiment 1) and mice (experiment 2). In experiment 1, decreases in sucrose intake were seen in rats exposed to chronic mild stress, but the effect was unr…