Search results for "Benzodiazepine"

[ 18 F]Fluoroethylflumazenil: a novel tracer for PET imaging of human benzodiazepine receptors

2001

5-(2'-[18F]Fluoroethyl)flumazenil ([18F]FEF) is a fluorine-18 labelled positron emission tomography (PET) tracer for central benzodiazepine receptors. Compared with the established [11C]flumazenil, it has the advantage of the longer half-life of the fluorine-18 label. After optimisation of its synthesis and determination of its in vitro receptor affinities, we performed first PET studies in humans. PET studies in seven healthy human volunteers were performed on a Siemens ECAT EXACT whole-body scanner after injection of 100-280 MBq [L8F]FEF. In two subjects, a second PET scan was conducted after pretreatment with unlabelled flumazenil (1 mg or 2.5 mg i.v., 3 min before tracer injection). A t…

Benzodiazepines for catatonic symptoms, stupor, and mutism.

1988

The GABAergic effect of low doses of lorazepam on social behavior

2002

The aim of this work was to test the antiaggressive effects of lorazepam and to determine whether these effects were mediated by benzodiazepine receptors. In a first experiment, male mice were injected with lorazepam in a range of low doses (0.05, 0.1, 0.2, and 0.6 mg/kg) or saline solution. In a second experiment, 1 mg/kg of Ro 15-1788, a benzodiazepine receptor antagonist, and a saline solution were injected before the behavioral test. Results showed that 0.6 mg/kg of lorazepam was the only dose that decreased the total duration of threat ( P < .01) and social investigation ( P < .05) and that 1 mg/kg of Ro 15-1788 had no effects. In the third experiment, animals received two injec- tions…

Benzodiazepine receptor interactions may be involved in the neurotoxicity of various penicillin derivatives

1980

The interaction of seven penicillin derivatives with specific [3H]flunitrazepam binding to benzodiazepine receptors was investigated. The affinities of the penicillins for benzodiazepine receptor seemed to depend on the lipophilia of the derivatives. The concentrations of the penicillins which inhibit specific [3H]flunitrazepam binding are consistent with penicillin levels found in the central nervous system of patients developing penicillin induced convulsions. The results suggest that penicillins inhibit GABAergic transmission not only at the GABA receptor, but also at the benzodiazepine receptor, which is thought to be part of a neuronal system facilitating GABAergic transmission. Both m…

The diversity of GABAA receptors. Pharmacological and electrophysiological properties of GABAA channel subtypes.

1998

The amino acid gamma-aminobutyric-acid (GABA) prevails in the CNS as an inhibitory neurotransmitter that mediates most of its effects through fast GABA-gated Cl(-)-channels (GABAAR). Molecular biology uncovered the complex subunit architecture of this receptor channel, in which a pentameric assembly derived from five of at least 17 mammalian subunits, grouped in the six classes alpha, beta, gamma, delta, sigma and epsilon, permits a vast number of putative receptor isoforms. The subunit composition of a particular receptor determines the specific effects of allosterical modulators of the GABAARs like benzodiazepines (BZs), barbiturates, steroids, some convulsants, polyvalent cations, and et…

Sensitive Screening of New Psychoactive Substances in Serum Using Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry.

2021

Abstract Analysis of new psychoactive substances (NPS) still poses a challenge for many institutions due to the number of available substances and the constantly changing drug market. Both new and well-known substances keep appearing and disappearing on the market, making it hard to adapt analytical methods in a timely manner. In this study we developed a qualitative screening approach for serum samples by means of liquid chromatography--quadrupole time-of-flight mass spectrometry. Samples were measured in data-dependent auto tandem mass spectrometry mode and identified by fragment spectra comparison, retention time and accurate mass. Approximately 500 NPS, including 195 synthetic cannabino…

Comparative studies on the detection of benzodiazepines in serum by means of immunoassays (FPIA).

1993

Serum was tested for benzodlazeplnes by fluorescence polarlzatlon Immunoassay (FPIA) on Abbott's ADx system uslng the benzodlazeplne serum reagents (Benzo S) and the benzodlazeplne urine reagents (Benzo U) after pretreatment of speclmens by means of acetone preclpltatlon. The followlng sera were included for comparing the two methods: negatlve sera spiked with varlous benzodlazeplnes; 80 sera randomly selected out of a total of 8654 serum specimens from Impalred drlvers; and blood speclmens from Indlvlduals who stated that they had taken benzodlazeplnes. The different benzodlazeplnes were added to serum st concentratlons of 25, 75, and 300 ng/mL. The low-dose benzodlazeplnes flunltrazepam a…

Diagnosis and therapeutic management of primary headache in an emergency setting

2013

Neuroprotective action of diazepam at very low and moderate doses in Alzheimer's disease model rats

2018

Abstract Early manifestations of Alzheimer's disease (AD) include neuroinflammation, disrupted neurotransmission and cognitive deficits. Impairment of the GABAergic system is essentially involved in the pathogenesis of AD. Traditionally, agonists of GABAA receptors at doses above 1 mg/kg are known to possess memory impairing effects. However, we have previously found that GABAA receptor GABA site ligand muscimol at very low doses acted contrary – enhanced spatial learning/memory, as well as prevented neuroinflammation and augmented neurotransmission in AD model rats. Therefore, in the present study we focused on the assessment of the effects of non-sedative – very low (0.05 mg/kg) and moder…

Early life stress is a risk factor for excessive alcohol drinking and impulsivity in adults and is mediated via a CRF/GABAA mechanism

2016

Childhood stress and trauma are associated with substance use disorders in adulthood, but the neurological changes that confer increased vulnerability are largely unknown. In this study, maternal separation (MS) stress, restricted to the pre-weaning period, was used as a model to study mechanisms of protracted effects of childhood stress/traumatic experiences on binge drinking and impulsivity. Using an operant self-administration model of binge drinking and a delay discounting assay to measure impulsive-like behavior, we report that early life stress due to MS facilitated acquisition of binge drinking and impulsivity during adulthood in rats. Previous studies have shown heightened levels of…