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...

Opioid receptors are a group of inhibitory G protein-coupled receptors with opioids as ligands. The endogenous opioids are dynorphins, enkephalins, endorphins...

The μ-opioid receptors (MOR) are a class of opioid receptors with a high affinity for enkephalins and beta-endorphin, but a low affinity for dynorphins...

An opioid antagonist, or opioid receptor antagonist, is a receptor antagonist that acts on one or more of the opioid receptors. Naloxone and naltrexone...

Opioid peptides or opiate peptides are peptides that bind to opioid receptors in the brain; opiates and opioids mimic the effect of these peptides. Such...

relief. As a class of substances, they act on opioid receptors to produce morphine-like effects. The terms 'opioid' and 'opiate' are sometimes used interchangeably...

The κ-opioid receptor or kappa opioid receptor, abbreviated KOR or KOP for its ligand ketazocine, is a G protein-coupled receptor that in humans is encoded...

values (Ki) of 0.051 nM for the μ-opioid receptor, 4.7 nM for the δ-opioid receptor, and 13 nM for the κ-opioid receptor in rat brain. Thus, carfentanil...

μ-, κ-, and δ-opioid receptors (Ki = 3.0, 4.7, and 15 nM in guinea pig brain membranes) with very low affinity for the sigma σ1 receptor (Ki = 1,800–4...

(~60%) with the ‘classical’ opioid receptors μ-OP (MOP), κ-OP (KOP), and δ-OP (DOP), it possesses little or no affinity for opioid peptides or morphine-like...