OPRD1

The OPRD1 gene encodes the delta-opioid receptor (DOR), a G-protein coupled receptor (GPCR) also known as OP1 or OPRD. Endogenous ligands like enkephalins bind to DOR, triggering Gαi/o-mediated signaling—this inhibits adenylate cyclase, lowers cyclic AMP (cAMP) levels, and modulates ion channel activity (e.g., potassium efflux and calcium influx), regulating neuronal excitability and neurotransmitter release.
DOR is linked to chronic pain, substance use disorders (opioid addiction), and mood disorders (depression, anxiety). Selective DOR agonists (e.g., SNC80) are studied for analgesia with reduced respiratory depression vs mu-opioid drugs. Antagonists and allosteric modulators are also explored to treat opioid dependence and mood-related conditions.