Dopamine D2 receptor (DRD2) (DRD2)

The Dopamine D2 receptor (DRD2) is a G protein-coupled receptor that serves as the primary inhibitory regulator of prolactin secretion in the pituitary gland (UniProt P14416). Dopamine, acting as a prolactin-inhibiting factor, binds to D2 receptors on lactotroph cells to suppress the synthesis and release of prolactin (StatPearls, Physiology, Dopamine). This pathway is clinically significant because many antipsychotic medications act as D2 receptor antagonists, which can inadvertently cause hyperprolactinemia, leading to symptoms such as galactorrhea and reproductive dysfunction (PubMed, PMID: 28224331). Conversely, D2 receptor agonists like cabergoline and bromocriptine are the first-line treatment for prolactinomas, effectively shrinking tumors and normalizing hormone levels (NIH, Prolactinoma). Beyond its endocrine role, the D2 receptor is a central target in neurology and psychiatry for managing Parkinson's disease and schizophrenia (PubChem, CID 1814). Its signaling involves the Gi/o protein family, which inhibits adenylyl cyclase and modulates ion channel activity (Wikipedia, Dopamine receptor D2).

Other names

D2RD2 dopamine receptorDopamine receptor D2D2 receptorDRD2

Dopamine D2 receptor agonists mimic the inhibitory effect of endogenous dopamine on pituitary lactotrophs to reduce prolactin secretion, whereas D2 receptor antagonists block this inhibition, resulting in elevated serum prolactin levels (StatPearls, Hyperprolactinemia).