There are four members of the opioid receptor family mu, delta, kappa and ORL-1. G protein linked receptors. Acute response to ligand binding differs from chronic response. Acute response includes dimerisation, endocytosis and inhibition of adenylyl cyclase, cAMP systems and hyperpolarization of the neuron. Chronic response includes altered G protein, adenylyl cyclase proteins, increased phosphorylation, receptor modulation, rectification of hyperpolarization and attenuation of extreme inhibition. New altered receptor activation and cell inhibition state achieved. Polymorphisms in receptor and enzyme pathways give insight into inter-individual response.
Chapter. 2244 words. Illustrated.
Subjects: Radiation Oncology ; Pain Medicine
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