title: The use of [3H]-[D-Pen2,D-Pen5]enkephalin as a highly selective ligand for the delta-binding site.
abstract: The characteristics of the binding of [3H]-[D-Pen2,D-Pen5]enkephalin were determined in homogenates of guinea-pig and rat brain. In the guinea-pig, the maximum binding capacity for [3H]-[D-Pen2,D-Pen5]enkephalin was 4.19 pmol g-1 and the KD 1.61 nM. In the rat, the corresponding values were 2.47 pmol g-1 and 5.42 nM. In both species, the maximum binding capacity and the affinity were not altered when mu-binding was suppressed with [D-Ala2,MePhe4,Gly-ol5]enkephalin. The mu-agonists, [D-Ala2,MePhe4,Gly-ol5]enkephalin and morphine, displaced a small portion of the binding of [3H]-[D-Pen2,D-Pen5]enkephalin with high affinities.
authors.forename: R
authors.initials: R
authors.lastname: Cotton
authors.forename: H W
authors.initials: HW
authors.lastname: Kosterlitz
authors.forename: S J
authors.initials: SJ
authors.lastname: Paterson
authors.forename: M J
authors.initials: MJ
authors.lastname: Rance
authors.forename: J R
authors.initials: JR
authors.lastname: Traynor
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D020881:Enkephalin, D-Penicillamine (2,5)-; D004745:Enkephalins / Q000378:metabolism*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008024:Ligands; D008297:Male; D009020:Morphine / Q000378:metabolism; D051381:Rats; D011957:Receptors, Opioid / Q000378:metabolism*; D017465:Receptors, Opioid, delta; D014316:Tritium
chemical_list: D004745:Enkephalins; D008024:Ligands; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D014316:Tritium; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D009020:Morphine; D020881:Enkephalin, D-Penicillamine (2,5)-