Potential use of DPCPX as probe for in vivo localization of brain A1 adenosine receptors.
The suitability of (3H)DPCPX (8-cyclopentyl-1,3-dipropylxanthine), a xanthine derivative, as an vivo probe for labelling adenosine A1 receptors was studied in rats. [3H]DPCPX (nM) penetrated largely into the brain (0.8% of the injected dose per gram of brain tissue 5 min after injection). Brain concentrations stayed at a plateau level from 5 to 15 min after the injection. The distribution in the different brain regions was heterogeneous with the highest amount of [3H]DPCPX in cerebellum and hippocampus and the lowest concentrations in hypothalamus and brain stem. Displacement (45-70% of total radioactivity) was obtained by the injection of 250 nM of cold DPCPX or cyclopentylxanthine, an analog of DPCPX. The ex vivo autoradiographic distribution of [3H]DPCPX was similar to the in vitro autoradiographic distribution of tritiated A1 adenosine receptor ligand as [3H]CHA. These results suggest the potential use of DPCPX for further in vivo investigation of A1 adenosine receptors with techniques such as positron emission tomography.
Bisserbe
J C
JC
Institut National de la Santé et de la Recherche Médicale (INSERM), Service Hospitalier Frédéric Joliot (SHFJ), Orsay, France.
Pascal
O
O
Deckert
J
J
Mazière
B
B
D000818:Animals; D001345:Autoradiography; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D009928:Organ Specificity; D011869:Radioligand Assay; D051381:Rats; D017207:Rats, Sprague-Dawley; D011983:Receptors, Purinergic / Q000032:analysis / Q000378:metabolism*; D014316:Tritium; D014970:Xanthines / Q000378:metabolism*
D011983:Receptors, Purinergic; D014970:Xanthines; D014316:Tritium; C051360:1,3-dipropyl-8-cyclopentylxanthine