TY - JOUR
T1 - Human delta opioid receptor
T2 - Functional studies on stably transfected Chinese hamster ovary cells after acute and chronic treatment with the selective nonpeptidic agonist SNC-80
AU - Malatynska, Ewa
AU - Wang, Yu
AU - Knapp, Richard J.
AU - Waite, Sue
AU - Calderon, Silvia
AU - Rice, Kenner
AU - Hruby, Victor J.
AU - Yamamura, Henry I.
AU - Roeske, William R.
PY - 1996/9
Y1 - 1996/9
N2 - The SNC-80 series of nonpeptidic agonists for the δ-opioid receptor are being developed as potential analgesic drugs. It is important to understand their acute and chronic effects at human δ-opioid receptors. Thus, we measured the ability of SNC-80 and [D-Pen2,4'-Cl-Phe4,D-Pen5]enkephalin to inhibit forskolin-stimulated adenylyl cyclase activity in recombinant Chinese hamster ovary cells stably expressing the cloned human δ-opioid receptor. The calculated EC50 values for [D-Pen2,4'-Cl-Phe4,D-Pen5]enkephalin and SNC-80 were 0.6 ± 0.1 nM and 6.3 ± 0.1 nM, respectively. Pretreatment of these cells with SNC-80 (100 nM) for 24 hr produced 1) a time-dependent reduction of δ receptor density, as measured by radioligand binding studies with [3H]naltrindole; 2) a shift in the EC50 value of SNC-80 from 7.7 ± 4.2 nM to 44.1 ± 12 nM, as measured by the cyclic AMP assay; 3) a reduction in the maximum inhibition of adenylyl cyclase activity from 86% to 48%; 4) a marked increase in the forskolin stimulation of basal cyclic AMP accumulation by nearly 100% (from 442 pmol/mg of protein to 824 pmol/mg of protein); and 5) a 5-fold increase in forskolin-stimulated cyclic AMP accumulation after addition of naltrindole. These studies showed that SNC-80 produced desensitization and down-regulation of human δ-opioid receptors in recombinant Chinese hamster ovary cells after chronic treatment and that this effect was associated with an increase in adenylyl cyclase activity.
AB - The SNC-80 series of nonpeptidic agonists for the δ-opioid receptor are being developed as potential analgesic drugs. It is important to understand their acute and chronic effects at human δ-opioid receptors. Thus, we measured the ability of SNC-80 and [D-Pen2,4'-Cl-Phe4,D-Pen5]enkephalin to inhibit forskolin-stimulated adenylyl cyclase activity in recombinant Chinese hamster ovary cells stably expressing the cloned human δ-opioid receptor. The calculated EC50 values for [D-Pen2,4'-Cl-Phe4,D-Pen5]enkephalin and SNC-80 were 0.6 ± 0.1 nM and 6.3 ± 0.1 nM, respectively. Pretreatment of these cells with SNC-80 (100 nM) for 24 hr produced 1) a time-dependent reduction of δ receptor density, as measured by radioligand binding studies with [3H]naltrindole; 2) a shift in the EC50 value of SNC-80 from 7.7 ± 4.2 nM to 44.1 ± 12 nM, as measured by the cyclic AMP assay; 3) a reduction in the maximum inhibition of adenylyl cyclase activity from 86% to 48%; 4) a marked increase in the forskolin stimulation of basal cyclic AMP accumulation by nearly 100% (from 442 pmol/mg of protein to 824 pmol/mg of protein); and 5) a 5-fold increase in forskolin-stimulated cyclic AMP accumulation after addition of naltrindole. These studies showed that SNC-80 produced desensitization and down-regulation of human δ-opioid receptors in recombinant Chinese hamster ovary cells after chronic treatment and that this effect was associated with an increase in adenylyl cyclase activity.
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M3 - Article
C2 - 8819489
AN - SCOPUS:0030431224
SN - 0022-3565
VL - 278
SP - 1083
EP - 1089
JO - Journal of Pharmacology and Experimental Therapeutics
JF - Journal of Pharmacology and Experimental Therapeutics
IS - 3
ER -