The selectivity of the opioid antagonist, naltrindole, for delta-opioid receptors.
In the mouse vas deferens, naltrindole gave pKB values of 9.7, 8.3, and 7.5 at the delta-, mu-, and kappa-sites and in binding assays, pIC50 values of 9.6, 7.8 and 7.2 at the same sites. The affinity of naltrindole for the delta binding site was increased in the presence of sodium ions and 5'-guanylylimidophosphate. Naltrindole is, thus, a potent opioid antagonist with marked selectivity for the delta-opioid receptor.
Rogers
H
H
Department of Neuropharmacology, Glaxo Group Research Ltd, Ware, Hertfordshire, UK.
Hayes
A G
AG
Birch
P J
PJ
Traynor
J R
JR
Lawrence
A J
AJ
D000818:Animals; D004558:Electric Stimulation; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D020881:Enkephalin, D-Penicillamine (2,5)-; D004745:Enkephalins / Q000494:pharmacology; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007211:Indoles / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009019:Morphinans / Q000494:pharmacology*; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism*; D009271:Naltrexone / Q000031:analogs & derivatives*; D009292:Narcotic Antagonists / Q000494:pharmacology*; D011957:Receptors, Opioid / Q000378:metabolism*; D017465:Receptors, Opioid, delta; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D012964:Sodium / Q000494:pharmacology; D014649:Vas Deferens / Q000187:drug effects / Q000378:metabolism
D004745:Enkephalins; D007211:Indoles; D009019:Morphinans; D009292:Narcotic Antagonists; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D006165:Guanylyl Imidodiphosphate; D009271:Naltrexone; D020881:Enkephalin, D-Penicillamine (2,5)-; D012964:Sodium; C055382:naltrindole