CHARACTERIZATION OF SUBTYPE-SPECIFIC ANTIBODIES TO THE HUMAN D-5 DOPAMINE-RECEPTOR - STUDIES IN PRIMATE BRAIN AND TRANSFECTED MAMMALIAN-CELLS

To achieve a better understanding of how D-5 dopamine receptors mediat e the actions of dopamine in brain, we have developed antibodies speci fic for the D-5 receptor. D-5 antibodies reacted with recombinant bacu lovirus-infected Sf9 cells expressing the D-5 receptor but not with th e D-1 receptor or a variety of other catecholaminergic and muscarinic receptors. Epitope-tagged D-5 receptors expressed in mammalian cells w ere reactive with both D-5 antibodies and an epitope-specific probe. A mixture of N-linked glycosylated polypeptides and higher molecular-ma ss species was detected on immunoblots of membrane fractions of D-5-tr ansfected cells and also of primate brain. D-5 receptor antibodies int ensely labeled pyramidal neurons in the prefrontal cortex, whereas spi ny medium-sized neurons and aspiny large interneurons of the caudate n ucleus were relatively lightly labeled. Antibodies to the D-5 dopamine receptor should prove important in experimentally determining specifi c roles for the D-5 and D-1 receptors in cortical processes and diseas es.