Further evidence that 3H-cis(Z)flupenthixol binds to the adenylate cyclase-associated dopamine receptor (D-1) in rat corpus striatum.
The proposal that 3H-cis(Z)flupenthixol (3H-FPT) preferentially binds to striatal dopamine receptors associated with adenylate cyclase activity (D-1), distinct from dopamine receptors to which 3H-haloperidol (3H-hal) binds (D-2), has been investigated further. The dopamine agonists bromocriptine and ergotamine were 60-times more potent as displacers of 3H-hal than 3H-FPT binding. Other dopamine agonists (ergometrine, dopamine, apomorphine, 2-amino-6,7-dihydroxy-tetralin (ADTN), and ergocornine) also shared this profile, although a smaller ratio was found for these compounds. Substituted benzamides (clebopride greater than sultopride greater than sulpiride greater than metoclorpramide greater than tiapride) displace 3H-hal but have only a very slight displacing effect towards 3H-FPT, and did not inhibit dopamine-stimulated adenylate cyclase activity. The same pattern is shared by oxiperomide and molindone. Together, these results support the idea that 3H-FPT labels another class of dopamine receptors than does 3H-hal, and that the former class most likely is associated with adenylate cyclase.
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D003342:Corpus Striatum / Q000378:metabolism*; D005475:Flupenthixol / Q000378:metabolism*; D066298:In Vitro Techniques; D051381:Rats; D011954:Receptors, Dopamine / Q000187:drug effects / Q000378:metabolism*; D013892:Thioxanthenes / Q000378:metabolism*
D011954:Receptors, Dopamine; D013892:Thioxanthenes; D000262:Adenylyl Cyclases; D005475:Flupenthixol