Dopamine receptor D2 (DRD2) and Dopamine receptor D3 (DRD3) (DRD2/DRD3)

The Dopamine receptor D2 (DRD2) and Dopamine receptor D3 (DRD3) are G protein-coupled receptors (GPCRs) belonging to the D2-like family, which primarily signal through the inhibition of adenylyl cyclase via Gi/o proteins (UniProt P14416, P35462). These receptors are critical regulators of motor control, reward-seeking behavior, and endocrine function, with high expression in the striatum, limbic system, and the anterior pituitary (NIH/NCBI Gene). In the periphery, D2 and D3 receptors are located in the gastrointestinal tract and the area postrema, where they modulate gastric motility and the emetic response (StatPearls, "Domperidone"). Domperidone is a specific antagonist of these receptors that does not readily cross the blood-brain barrier, making it effective for treating nausea and gastroparesis without significant central nervous system side effects (PubChem CID 3151). However, its antagonism of D2 receptors in the pituitary can lead to increased prolactin secretion, and its interaction with cardiac ion channels poses a risk for QT prolongation (PubMed PMID 21843106). These receptors are also the primary targets for antipsychotic medications and dopamine agonists used in the management of schizophrenia and Parkinson's disease, respectively (StatPearls, "Dopamine Antagonists").

Other names

D2 dopamine receptorD3 dopamine receptorD2RD3RD(2) receptorD(3) receptor

Antagonism of peripheral D2 and D3 receptors to increase gastrointestinal motility and inhibit the emetic reflex; central antagonism for antipsychotic effects; central agonism for antiparkinsonian effects.