Attenuation of opioid tolerance by ETB receptor agonist IRL-1620 is independent of an accompanied decrease in nerve growth factor in mice

摘要

AimETA receptor antagonists reverse opioid tolerance but the involvement of ETB receptors is unknown. In morphine or oxycodone tolerant mice we investigated (1) the effect of ETB receptor agonist, IRL-1620, on analgesic tolerance; (2) changes in expression of the brain ETA and ETB receptors; and (3) alterations in the brain VEGF, NGF, PI3K and notch-1 expression.