title: Ionic conditions differentially affect 3H-DADL binding to type-I and type-II opiate delta receptors in vitro.
abstract: It is widely accepted that the prototypic delta agonist DADL (D-ala2-D-leu5-enkephalin) labels two binding sites in vitro. Using the site directed, receptor selective alkylating agents, BIT and FIT (Rice et al.. Science 220:314-316, 1983), we recently described (Rothman et al, Neuropeptides, in press) the preparation of membranes possessing only lower affinity 3H-DADL binding sites (FIT-treated membranes, type-I delta sites) as well as membranes greatly enriched with higher affinity binding sites (BIT-treated membranes, type-II delta sites). In this paper we report that ionic conditions differentially affect the binding of 3H-DADL to FIT- and BIT-treated membranes, supporting the notion that 3-H-DADL labels two distinct delta binding sites.
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D002118:Calcium / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives* / Q000378:metabolism; D016308:Enkephalin, Leucine-2-Alanine; D005283:Fentanyl / Q000031:analogs & derivatives / Q000494:pharmacology; D017879:Isothiocyanates; D007700:Kinetics; D008345:Manganese / Q000494:pharmacology; D009994:Osmolar Concentration; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000187:drug effects / Q000378:metabolism*; D017465:Receptors, Opioid, delta; D012964:Sodium / Q000494:pharmacology; D013861:Thiocyanates / Q000494:pharmacology
chemical_list: D017879:Isothiocyanates; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D013861:Thiocyanates; D008345:Manganese; D004743:Enkephalin, Leucine; D016308:Enkephalin, Leucine-2-Alanine; C037091:fentanyl isothiocyanate; C042097:2-(4-ethoxybenzyl)-1-diethylaminoethyl-5-isothiocyanatobenzimidazole; D012964:Sodium; D002118:Calcium; D005283:Fentanyl