Compounds selective for dopamine receptor subtypes

Novel dopamine (DA) receptor proteins of relatively low natural abundance and uncertain physiology can be expressed selectively in genetically transfected cultured cells to facilitate screening of novel DA receptor ligands. Selective agonists or antagonists for most of the five major DA receptor types are emerging, but better D 4 and D 5 agonists, D 3 and D 5 antagonists, and more selective D 2 antagonists are needed. Clinical development of such compounds as diagnostic neuroradiopharmaceuticals or neuropsychiatric drugs remains empirical and somewhat unpredictable. The search for novel receptor-selective agents can be enhanced by better understanding of the physiology and pharmacology of DA neuroreceptors.