Comparative autoradiographic distribution of central omega (benzodiazepine) modulatory site subtypes with high, intermediate and low affinity for zolpidem and alpidem.

Pharmacological characterization of [3H]benzodiazepine binding to membrane preparations of adult rat hippocampus and neonatal rat brain have demonstrated, in addition to the omega 1 and omega 2 populations of central omega benzodiazepine binding sites associated with GABAA receptors, the existence of binding sites with microM affinity for the imidazopyridines zolpidem and alpidem. In the present study we have investigated their comparative autoradiographic distribution using [3H]flumazenil as a ligand. In the neonatal rat CNS, the imidazopyridine derivatives zolpidem and alpidem were found to discriminate two [3H]flumazenil binding site populations with an IC50 value ratio of more than 200-fold.

Comparative in vivo and in vitro regional selectivity of central omega (benzodiazepine) site ligands in inhibiting [3H]flumazenil binding in the rat central nervous system.

The in vivo selectivity for central omega (benzodiazepine) modulatory site subtypes of ligands from several chemical classes has been evaluated by measuring the displacement of the in vivo binding of [3H]flumazenil to several rat central nervous system structures differentially enriched in omega 1 and omega 2 sites. This labeling was prevented in a dose-related manner by the i.p.

Pharmacological characterization of in vivo [3H]lfenprodil binding sites in the mouse brain.

Intravenous injection of 5 muCi of [3H]ifenprodil to mice resulted in an accumulation of radioactivity in the whole brain which was maximal at 5 min postinjection and then declined in a biphasic manner. When whole brain radioactivity was measured 2 h after [3H]ifenprodil injection, more than 65% of the incorporated label was displaced by i.p.

In vivo interaction of zolpidem with central benzodiazepine (BZD) binding sites (as labeled by [3H]Ro 15-1788) in the mouse brain. Preferential affinity of zolpidem for the omega 1 (BZD1) subtype.

Zolpidem is a novel hypnotic drug which possesses preferential affinity, under in vitro conditions, for the omega 1 (BZD1) subtype of BZD binding sites. In the present study the in vivo interaction of zolpidem with mouse brain BZD binding sites, as labeled by i.v.

Imaging of primary and remote ischaemic and excitotoxic brain lesions. An autoradiographic study of peripheral type benzodiazepine binding sites in the rat and cat.

Seven days after unilateral middle cerebral artery occlusion in rats, peripheral type benzodiazepine binding sites (PTBBS), using [3H]PK 11195 as a specific radioligand, were greatly increased in the cortical and striatal regions surrounding the focus of infarction with smaller increases in the ventrolateral and posterior thalamic complexes and in the substantia nigra, all ipsilateral to the occlusion. Similarly, PTBBS increases were observed in the caudate nucleus and entorhinal cortex of cats likewise subjected to prior unilateral occlusion of the middle cerebral artery. Intrastriatal administration of N-methyl-D-aspartate (250 nmol) in the rat resulted in a dramatic ipsilateral increase in PTBBS levels in the striatum and in the deeper laminae of the ipsilateral frontoparietal cortex.