the anticonvulsant activity of astragalus squarrosus total extract was assessed in pentylenetetrazole (ptz)-induced convulsion in mice, with diazepam as the standard drug, while mechanistic studies were also conducted using flumazenil, a gaba a-benzodiazepine receptor complex site antagonist. the extract produced protection against convulsion at 400 mg/kg, comparable with protection of benzodia...

Interactions of mu-opioid receptors with the benzodiazepine system were studied by examining the modulatory effects of flumazenil (a benzodiazepine antagonist) and alprazolam (a benzodiazepine agonist) on the respiratory effects of the opioid peptide dermorphin. Dermorphin, 1-30 nmol administered i.c.v., to conscious, unrestrained rats decreased ventilation rate (VR) and minute volume (MV) dose...

We performed positron emission tomographic (PET) measurements of the regional distribution volume of benzodiazepine receptors and regional glucose metabolism in 6 drug-free patients with early Huntington's disease following injection of [11C]flumazenil, a nonsubtype selective central benzodiazepine receptor antagonist, and 18F-2-fluoro-2-deoxy-D-glucose, respectively. Flumazenil data were analy...

CLINICAL PHARMACOLOGY Lorazepam interacts with the γ-aminobutyric acid (GABA)-benzodiazepine receptor complex, which is widespread in the brain of humans as well as other species. This interaction is presumed to be responsible for lorazepam’s mechanism of action. Lorazepam exhibits relatively high and specific affinity for its recognition site but does not displace GABA. Attachment to the speci...

OBJECTIVES To determine whether differences in cognitive function between alcoholic and non-alcoholic cirrhotic patients relate to differences in endogenous ligands for the benzodiazepine receptor and/or benzodiazepine binding. METHODS Seventeen grade-I hepatic encephalopathic patients (nine alcoholic, eight non-alcoholic) were compared with 10 matched controls on plasma concentrations of end...

PURPOSE To establish whether regional disturbances of the benzodiazepine receptor distribution in focal epilepsies can be detected by SPECT using 123-I-Iomazenil. PATIENTS AND METHODS Benzodiazepine receptor imaging was carried out in 10 patients interictally. To be eligible for this study the patients had to have a history of focal seizures and no evidence of routine imaging abnormalities as...

GABA and its associated benzodiazepine interactions play an important role in basal ganglia function. Distinctive GABA, benzodiazepine and opiate receptor changes occur in response to striatal lesions and in the human neurodegenerative disorder, Huntington's disease (HD). In animal experiments, the in vivo administration of [3H]flunitrazepam labels benzodiazepine receptors and can demonstrate t...

Quantitative radiohistochemistry was utilized to study alterations of gamma-aminobutyric acid (GABA) and benzodiazepine receptors in the kindling model of epilepsy. The radioligands used for GABA and benzodiazepine receptors were [3H] muscimol and [3H]flunitrazepam, respectively. GABA receptor binding was increased by 22% in fascia dentata of the hippocampal formation but not in neocortex or su...