Opioid receptors

Opioid receptors

Receptors located in the brain and various organs that bind opiates or opioid substances.

Mentioned in: Methadone

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opioid receptors,

n.pl any of the several receptors to which opiates bind. Classified into three groups delta, kappa, and mu based on the specific substances they bind and the resulting physiologic effects.

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opioid

1. any synthetic narcotic that has opiate-like activities but is not derived from opium.

2. denoting naturally occurring peptides, e.g. enkephalins, that exert opiate-like effects by interacting with opiate receptors of cell membranes.

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endogenous opioid

see endorphin, enkephalin.

opioid receptors

specific receptor sites for opioids, named for the drugs which have a high binding affinity for them. The main ones are mu (morphine), kappa (opioid agonist-antagonists such as pentazocine) and delta (enkephalin endogenous opioids). Subtypes exist and others, such as sigma and epsilon, have been identified.