Opioid Peptides and Opioid Receptors in Cells of the Immune System

I Abbreviations used: ACTH, adrenocorticotropic hormone; ADCC, antibody-dependent cellular cytotoxicity; Bma .. total number of binding sites; BREM, bremazocine, an agonist with modest selectivity for K sites; CCK, cholecystokinin; ConA, concanavalin A; DADLE, D-Ala2,D-LeuSenkephalin, an agonist somewhat selective for /j �ites; DEX, dextrorphan, inert enantiomer of LEV; DHM, dihydromorphine, a Jl-selective agonist; DIP, dipre­ norphine, a relatively nonselective antagonist; DYN, dynorphin, a peptide product of the dynorphin gene, selective for K sites; EKC, ethylketazocine, a benzomorphan agonist with modest selectivity for K sites; END, endorphin; a peptide product of the pro-opio­ melanocortin gene; <Xand y-endorphin are fragments of fJ-endorphin; fJ-endorphin is selective for e sites; ETO, etorphine, a relatively nonselective agonist; fMLP, formyl-methio­ nyl-leucinyl-phenylalanine; granulo, granulocyte(s); h, human; ICso, concentration of a com­ peting ligand that reduces specific binding of radioligand by 50%; icv, intracerebro­ ventricular; IFN, interferon; ir-, immunoreactive; Kd, K;, equilibrium dissociation con­ stants, determined by binding isotherm or by competition, respectively; LENK, Leuen­ kephalin, a minor product of the pro-enkephalin gene, an agonist somewhat selective for {) sites; leuko, leukocyte(s); LEV, levorphanol, a Jl-selective agonist; Iympho, Iymphocyte(s); m, mouse; M.p, macrophage(s); MENK, Metenkephalin, major product of the pro-enkephalin gene, a /j-selective agonist; MNC, mononuclear cell(s); mono, monocyte(s); MOR, morphine, a Jl-selective agonist; NA, not applicable; NAL, naloxone, a moderately jl-selective antag­ onist; NK, natural killer; NR, not reported; NTX, naltrexone, a long-lasting Jl-selective antagonist closely related to naloxone; PBL, peripheral blood Iymphocyte(s); PBMNC, peripheral blood mononuclear cell(s); PHA, phytohemagglutinin; PMNL, polymorpho­ nuclear leukocyte(s); r, rat; RIA, radioimmunoassay; spleno, splenocyte; SRBC, sheep red blood cells; VIP, vasoactive intestinal peptide.