Characterization of the delta-opioid receptor found in SH-SY5Y neuroblastoma cells.
The delta-opioid receptor found in SH-SY5Y cells was characterized in terms of binding profile and ability to mediate the inhibition of forskolin-stimulated cAMP accumulation. Both DPDPE ([D-Pen2,D-Pen5]enkephalin) and deltorphin II, compounds reported to be selective for the delta 1- and delta 2-opioid receptor respectively, were potent agonists in these cells. Binding studies indicated that naltrindole benzofuran (NTB) had significantly higher affinity than 7-benzylidenenaltrexone (BNTX); however, both compounds have high affinity for the delta-opioid receptor found in SH-SY5Y cells. Naltrindole benzofuran was found to be a potent antagonist, with an IC50 of less than 1 nM, while 7-benzylidene naltrexone was found to be a relatively weak antagonist, requiring greater than 100 nM to inhibit 50% of agonist activity. Binding to intact SH-SY5Y cells was compared to binding to cell membranes and guinea-pig brain membranes. In each case, binding affinities were very similar. These studies suggest that the receptor found in SH-SY5Y cells could probably be classified as a delta 2-opioid receptor. However, the very similar binding characteristics of SH-SY5Y cells and guinea-pig brain membranes call into question the ability to label delta 1-opioid receptors.
Toll
L
L
Department of Neuroscience, SRI International, Menlo Park, CA 94025, USA. larry_toll@qm.sri.com
Polgar
W E
WE
Auh
J S
JS
D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D006168:Guinea Pigs; D006801:Humans; D008566:Membranes / Q000378:metabolism; D009447:Neuroblastoma / Q000378:metabolism* / Q000473:pathology; D017480:Receptors, sigma / Q000187:drug effects / Q000378:metabolism*; D014407:Tumor Cells, Cultured / Q000378:metabolism
D017480:Receptors, sigma; D000242:Cyclic AMP