The mu-opioid receptor gene polymorphism (A118G) alters HPA axis activation induced by opioid receptor blockade
An A118G nucleotide exchange in exon 1 of the mu-opioid receptor causes an Asn40Asp
substitution polymorphism in the receptor's extracellular domain. In vitro studies show that
the Asp40 variant of the mu-opioid receptor binds β-endorphin three times more avidly than
the more common Asn40 variant. Paraventricular corticotropin releasing hormone neurons,
which activate the HPA axis, express mu-opioid receptors and are modulated by β-
endorphin neurons. This preliminary study was designed to test the hypothesis that the …
substitution polymorphism in the receptor's extracellular domain. In vitro studies show that
the Asp40 variant of the mu-opioid receptor binds β-endorphin three times more avidly than
the more common Asn40 variant. Paraventricular corticotropin releasing hormone neurons,
which activate the HPA axis, express mu-opioid receptors and are modulated by β-
endorphin neurons. This preliminary study was designed to test the hypothesis that the …