Δ-opioid receptor

Δ-opioid receptor (also known as DOR) is one of the four members of the opioid receptor family, along with the mu-opioid receptor (MOR), kappa-opioid receptor (KOR), and nociceptin receptor (NOP). These receptors are a group of G protein-coupled receptors (GPCRs) that are activated by the body's own endorphins as well as by exogenous compounds, such as morphine and other opioids.

Function[edit]

The Δ-opioid receptor primarily mediates the effects of the endogenous opioids enkephalins. It is involved in a variety of physiological and pathological processes, including pain modulation, mood regulation, immune response, and neuroprotection.

Structure[edit]

Like other GPCRs, the Δ-opioid receptor is composed of seven transmembrane domains connected by three extracellular and three intracellular loops. The N-terminus is located extracellularly, while the C-terminus is intracellular.

Ligands[edit]

Several endogenous and exogenous ligands are known to bind to the Δ-opioid receptor. The endogenous ligands include the enkephalins, while the exogenous ligands include a variety of opioids, such as deltorphins and naltrindole.

Clinical significance[edit]

The Δ-opioid receptor is a potential target for the treatment of pain, depression, and anxiety disorders. However, the development of selective Δ-opioid receptor agonists has been challenging due to the high homology between the opioid receptors.