HUMAN DELTA-OPIOID RECEPTOR - A STABLE CELL-LINE FOR FUNCTIONAL-STUDIES OF OPIOIDS

A HUMAN delta opioid receptor cDNA clone (pREP10/hDOR) was transfected into Chinese hamster ovary (CHO) cells. The stable cell line expresse d a high density of delta opioid receptors (137 000 +/- 21 600 recepto rs/cell). DPDPE inhibited 90% of the forskolin-stimulated cAMP accumul ation in these cells with high potency (EC(50) = 1.3 nM). This effect of DPDPE was antagonized by naltrindole. The pseudo-pA(2) value (K-e) of 155 pM for naltrindole is consistent with that measured for delta r eceptor antagonism in the mouse vas deferens. This is the first detail ed characterization of DPDPE activity on forskolin-stimulated cAMP acc umulation mediated through a human delta opioid receptor. The data sup port the use of the recombinant cell line for functional studies of op ioid drugs.