Opioid receptors have three major classes mu delta

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Opioid Receptors have three major classes: (mu), (delta) and (kappa) G protein-coupled and have 7 transmembrane spanning regions Receptor classes have specificity for certain opioids Each class has subtypes; these can vary dramatically in their effects, even when stimulated by the same ligand Orphan receptor (ORL) was recently discovered and other receptors may also exist (   is not Distribution in the CNS is broad but varies by receptor class Intracellular activity can vary by class
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Opioid receptor distribution in the brain ORL1
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Opioid peptide cellular signalling is metabotropic and has three primary effects driven by Gi activation Inhibit adenylyl cyclase influence (inhibit) Na + influx inhibit neurotransmitter release inhibit stimulatory effects of other neurotransmitters Open K + channels increase movement of K + out of the cell hyperpolarize the cell Inhibit Ca ++ channels decreased Ca ++ entry inhibit neurotransmitter release
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Opioid receptor activation results in a number of different cellular responses
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