Δ-opioid receptor
Channel: all the knowledge of the universe PRINCIPIA
Date: 2022-01-25

Δ-opioid receptor, by Wikipedia https://en.wikipedia.org/wiki?curid=10059094 / CC BY SA 3.0

#Genes_on_human_chromosome_1
#G_protein-coupled_receptors
#Opioid_receptors
The δ-opioid receptor, also known as delta opioid receptor or simply delta receptor, abbreviated DOR or DOP, is an inhibitory 7-transmembrane G-protein coupled receptor coupled to the G protein Gi/G0 and has enkephalins as its endogenous ligands.
The regions of the brain where the δ-opioid receptor is largely expressed vary from species model to species model.
In humans, the δ-opioid receptor is most heavily expressed in the basal ganglia and neocortical regions of the brain.
The endogenous system of opioid receptors is well known for its analgesic potential; however, the exact role of δ-opioid receptor activation in pain modulation is largely up for debate.
This also depends on the model at hand since receptor activity is known to change from species to species.
Activation of delta receptors produces analgesia, perhaps as significant potentiators of μ-opioid receptor agonists.
However, it seems like delta agonism provides heavy potentiation to any mu agonism.
Therefore, even selective mu agonists can cause analgesia under the right conditions, whereas under others can cause none whatsoever.
It is also suggested however that the pain modulated by the μ-opioid receptor and that modulated by the δ-opioid receptor are distinct types, with the assertion that DOR modulates the nociception of chronic pain, while MOR modulates acute pain.
Evidence for whether delta agonists produce respiratory depression is mixed; high doses of the delta agonist peptide DPDPE produced respiratory depression in sheep,
but in tests on mice the non-peptide delta agonist SNC-80 produced respiratory depression only at the very high dose of 40 mg/kg.
In contrast both the peptide delta agonist Deltorphin II and the non-peptide delta agonist （+）-BW373U86 actually stimulated respiratory function and blocked the respiratory depressan...