The mu opioid receptor: from molecular
cloning to functional studies

by
Yu L.
Indiana University School of Medicine,
Indiana, USA.
Addict Biol. 1996;1(1):19-30


ABSTRACT

Opioids have been used and abused by humans for centuries. The mu opioid receptor represents the high affinity binding site for opioid narcotics with high abuse liability such as morphine, codeine and fentanyl. Heroin (diacetylmorphine), a semi-synthetic derivative of morphine, crosses the blood-brain barrier more readily than morphine due to its increased hydrophobicity. Once in the brain heroin is hydrolyzed to morphine, which acts at the mu opioid receptor and results in euphoria, thus conferring the reinforcing properties of heroin. Using molecular biology techniques, the mu opioid receptors from several species have been cloned. This article reviews recent progress in this area, with respect to the two major cellular functions of the mu opioid receptor: reduction of intracellular cAMP concentration by inhibiting adenylyl cyclase activity, and inhibition of neuronal firing by modulating membrane ion channels.
Mu
Pain
Heroin
SOD mu
Tolerance
Methadone
Naloxonazine
Receptor subtypes
Morphine/verapamil
Fentanyl and ketamine
Dynorphin and dopamine
Mu opioid receptor subtypes
Genes, pharmacology and mu
Depression, opioids and the HPA
Kappa upregulation and addiction
Opioids, goldfish and the giant toad
Mice without mu don't miss their moms
Opioids, depression and learned helplessness