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Dopamine Antagonists (dopamine + antagonist)

Distribution by Scientific Domains

Medical Sciences	60%

Selected Abstracts

Induced ovulation of yellow catfish (Pelteobagrus fulvidraco) using a combination of a gonadotrop-releasing hormone analogue and domperidone

AQUACULTURE RESEARCH, Issue 8 2010
Youji Wang
Abstract The effects of an intraperitoneal hormone injection of gonadotropin-releasing hormone agonist (D-Ala6, Pro9 -NEt GnRHa) alone or in combination with a dopamine antagonist, domperidone (DOM), on ovulation induction in yellow catfish Pelteobagrus fulvidraco were tested. The hormone treatments were as follows: 6 mg kg,1 body weight (BW) of carp pituitary extract as a positive control, GnRHa 10, 20, 40 and 80 ,g kg,1 BW and a combination of GnRHa and DOM as follows: 10 ,g+5 mg, 20 ,g+10 mg, 40 ,g+20 mg and 80 ,g+40 mg kg,1 BW. Physiological saline (0.7% NaCl) was used as a negative control. Significant differences in the ovulation ratio, latency period and ovulation index (OI) were observed among treatments (P<0.05). The combination of GnRHa and DOM at doses of 40 ,g+20 mg kg,1 BW had higher values of the ovulation ratio and OI, and a shorter latency period compared with other treatments. The highest OI in GnRHa treatments was only 56.67%, suggesting a dopaminergic tone on gonadotropin secretion in this fish at the pre-ovulatory stage. Therefore, ovulation can be successfully induced in yellow catfish with 40 ,g kg,1 GnRHa+20 mg kg,1 DOM without affecting the egg quality. [source]

Molecular mechanisms underlying glutamatergic dysfunction in schizophrenia: therapeutic implications

JOURNAL OF NEUROCHEMISTRY, Issue 4 2009
Pablo A. Gaspar
Abstract Early models for the etiology of schizophrenia focused on dopamine neurotransmission because of the powerful anti-psychotic action of dopamine antagonists. Nevertheless, recent evidence increasingly supports a primarily glutamatergic dysfunction in this condition, where dopaminergic disbalance is a secondary effect. A current model for the pathophysiology of schizophrenia involves a dysfunctional mechanism by which the NMDA receptor (NMDAR) hypofunction leads to a dysregulation of GABA fast- spiking interneurons, consequently disinhibiting pyramidal glutamatergic output and disturbing the signal-to-noise ratio. This mechanism might explain better than other models some cognitive deficits observed in this disease, as well as the dopaminergic alterations and therapeutic effect of anti-psychotics. Although the modulation of glutamate activity has, in principle, great therapeutic potential, a side effect of NMDAR overactivation is neurotoxicity, which accelerates neuropathological alterations in this illness. We propose that metabotropic glutamate receptors can have a modulatory effect over the NMDAR and regulate excitotoxity mechanisms. Therefore, in our view metabotropic glutamate receptors constitute a highly promising target for future drug treatment in this disease. [source]

Contemporary encephalitis lethargica presenting with agitated catatonia, stereotypy, and dystonia-parkinsonism

MOVEMENT DISORDERS, Issue 15 2007
Russell C. Dale PhD
Abstract Encephalitis lethargica (EL) syndrome was classically described by Von Economo and has somnolent-ophthalmoplegic, hyperkinetic, and amyostatic-akinetic forms. We describe 2 recent cases of EL characterized by an acute encephalitis with mixed movement disorders (dystonia-Parkinsonism plus stereotypy) and psychiatric disorders (agitated catatonia, coprolalia, and echo phenomena). Both patients suffered concurrent hyperkinetic and Parkinsonian features resulting in therapeutic challenges. Bradykinetic features responded to dopamine replacement therapy and both patients also had adverse affects to dopamine antagonists (oculogyric crises plus neuroleptic malignant syndrome). Investigation was unremarkable other than the presence of CSF lymphocytosis and oligoclonal bands. Despite prolonged in-patient stays and intensive care management, both patients have made complete recoveries. We believe these cases support the hypothesis that this syndrome is an inflammatory encephalitis that specifically effects dopamine neurotransmission. © 2007 Movement Disorder Society [source]

Contribution of perospirone and risperidone to reduce delirium in senile patients

PSYCHOGERIATRICS, Issue 1 2008
Michikazu USHIJIMA
Abstract Background:, Serotonin,dopamine antagonists (SDAs) inhibit dopaminergic transmission in the mesolimbic system less than in the nigrostriatal dopaminergic pathway, which relates to the extrapyramidal side-effects of these drugs. The SDAs seem to have an adequate receptor binding profile for the management of the behavioral and psychiatric symptoms of dementia. However, clinicians are discouraged from prescribing SDAs for elderly patients because of an advisory statement from the US Food and Drug Administration that warns about an increased mortality rate among elderly patients treated with atypical antipsychotics. Methods:, We conducted a retrospective study involving 16 elderly patients (mean age 84.9 years; range 67,94 years) with delirium who were treated with one of two SDAs, namely perospirone (4,12 mg/day) or risperidone (1,2 mg/day). The time-course of their psychiatric symptoms was assessed using subcategories of the Delirium Rating Scale (DRS) before treatment and on Days 10 and 24 of treatment. Results:, Total DRS scores were significantly decreased from baseline in both treatment groups. Both agents led to significant improvements from baseline in psychomotor behavior and lability of mood. Of interest, perospirone decreased hallucinations and delusions and improved sleep,awake cycle disturbances compared with baseline. No serious side-effects were seen with either drug. Conclusions:, Both perospirone and risperidone are effective in the management of delirium in elderly patients. The improvement in the sleep,awake cycle with perospirone may be derived from its short pharmacological half-life. [source]

Probable dystonic reaction after a single dose of cyclizine in a patient with a history of encephalitis

ANAESTHESIA, Issue 3 2003
H. King
Summary A patient underwent an emergency Caesarean section under general anaesthesia for an antepartum haemorrhage. Following delivery of a live infant, cyclizine was administered in accordance with departmental anti-emetic protocol. On awakening she was confused, slow to articulate and had slurred speech. A computed tomography (CT) scan, which was performed to exclude an intracranial event, was normal. Her symptoms were suggestive of a lingual,facial,buccal dyskinesia as seen with dopamine antagonists. A presumptive diagnosis of a dystonic reaction to cyclizine was made. She received two doses of procyclidine before her symptoms completely resolved. Cyclizine has had a resurgence in popularity owing to the recent withdrawal of droperidol and anaesthetists should be aware that, although extremely rare, dystonic reactions may occur with this agent. [source]