%0 Journal Article
%T Transgenic increase in the β-endorphin concentration in cerebrospinal fluid alleviates morphine-primed relapse behavior through the μ opioid receptor in rats.
%A He Y
%A Lu Y
%A Shen Y
%A Wu F
%A Xu X
%A Kong E
%A Huang Z
%A Sun Y
%A Yu W
%J J Med Virol
%V 91
%N 6
%D 06 2019
%M 30701563
%F 20.693
%R 10.1002/jmv.25415
%X Opioid-primed relapse is a global burden. Although current strategies have improved, optimal therapy is urgently needed.
A recombinant adenovirus (Ad-NEP) expressing β-endorphin (β-EP) was designed and injected intracerebroventricularly (icv) into the right lateral ventricle in rats. Spatial and temporal β-EP expression in the lateral ventricle wall, subventricular zone and adjacent choroid plexus and the β-EP concentration in the cerebrospinal fluid (CSF) were observed during a 21-day period. A morphine priming-induced conditioned place preference (CPP) rat model was established. The β-EP-ir neuron counts, CSF β-EP concentration, and CPP score, which were used to evaluate morphine-primed reinstatement following extinction, were recorded 7 days after the icv injection. Additionally, the rats were pretreated with the irreversible μ opioid receptor antagonist β-funaltrexamine (β-FNA) and the selective κ opioid receptor antagonist nor-binaltorphimine (nor-BNI) to identify the receptor-dependent mechanism.
Both peak β-EP expression in target neurons and the peak CSF β-EP concentration occurred 7 to 8 days after Ad-NEP icv injection. The sustainable increase in the CSF β-EP concentration was correlated with a decrease in the CPP score 7 days after the Ad-NEP icv injection. Furthermore, reinstatement was almost reversed by β-FNA pretreatment 24 hours before the behavioral test, but nor-BNI had little effect.
The increasing cerebrospinal fluid β-endorphin concentrations showed that the therapeutic effect on opioid relapse occurred predominantly through a μ opioid receptor-dependent mechanism. The Ad-NEP adenovirus can be considered an alternative therapy for opioid relapse.