Preparation of a bromine-76 labelled analogue of epibatidine: a potent ligand for nicotinic acetylcholine receptor studies.

Epibatidine analogues have been labelled with I-123 for single photon emission computed tomography and with short half-life positron emitters (C-11 and F-18) for PET. For easier radiopharmacological studies the bromo analogue of epibatidine (norchlorobromoepibatidine or exo-7-azabicyclo-2-(2-bromo-5-pyridyl)-[2.2.

Pharmacological evaluation of a Br-76 analog of epibatidine: a potent ligand for studying brain nicotinic acetylcholine receptors.

[(76)Br]-Norchlorobromoepibatidine ([(76)Br]BrPH) is a specific and high affinity radioligand for the nicotinic acetylcholine receptors (nAChRs). In vitro, on rat thalamus membranes [(76)Br]BrPH bound to two sites with apparent affinities of 8 pM and 3 nM. The density of binding sites were 1.

(+)-[76Br]A-69024: a non-benzazepine radioligand for studies of dopamine D1 receptors using PET.

(+)-[76Br]A-69024 is a specific and enantioselective dopamine D1 receptor radioligand. The Bmax of (+)-[76Br]A-69024 measured in vitro on rat striatum membranes was 320 +/- 25 fmoles/mg protein with an apparent dissociation constant of Kd = 0.6 +/- 0.

Use of bromine-76 and iodine-123 radiohalogenated tracers in the drug development process.

The only bromine and iodine radioisotopes worth using in PET or SPECT in vivo investigations during the development of a new drug are 76Br and 123I. It is most of the time impossible to isotopically label a drug with 76Br or 123I since the occurrence of drugs having a bromine or an iodine atom within their chemical structure is quite limited. However, by using specific radiobrominated or radioiodinated probes, it is possible to study in vivo the potential interaction of a drug with biochemical processes such as blood flow, glucose consumption, protein synthesis or cell proliferation and neurotransmission.

Extrastriatal and striatal D(2) dopamine receptor blockade with haloperidol or new antipsychotic drugs in patients with schizophrenia.

Background: Both traditional and atypical antipsychotics have been hypothesised to be effective in schizophrenia through limbic and cortical D(2) dopamine receptor blockade.

Aims: To investigate this hypothesis with the D(2)/D(3)-selective positron emission tomography (PET) probe [(76)Br]-FLB457.

Method: PET scans were performed on 6 controls and 18 patients with schizophrenia treated with haloperidol or with risperidone, clozapine, amisulpride or olanzapine.