title: Inhibition of chemokine-induced chemotaxis of monkey leukocytes by mu-opioid receptor agonists.
abstract: It is recognized that chemotaxis and phagocytosis constitute the first line of defense in the immune system, and chemokines function mainly as chemoattractants for phagocytic cells, recruiting monocytes and neutrophils from the blood to sites of infection. In this study, chemotaxis of monkey leukocytes was evaluated using human chemokines IL-8 (interleukin-8), MIP-1 beta and RANTES as the chemoattractants, and the effects of micro-opioid receptor agonists, morphine, DAMGO, methadone and endomorphine, on the efficiency of chemotaxis were examined. It was found that human chemokines served well as chemoattractants for monkey leukocytes, and similar to the human system, chemokine-induced chemotaxis of monkey leukocytes was inhibited in the presence of micro-opioid receptor agonists. The inhibition could be reversed by naloxone, a specific micro-opioid receptor antagonist. These studies further support the value of the monkey model for drug abuse studies in humans, as well as suggest that opioids such as morphine may alter immune functions through micro-opioid receptors on leukocytes.
authors.affiliation: Department of Medical Pharmacology & Toxicology, University of California, Davis 752-7710, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Choi
authors.forename: L F
authors.initials: LF
authors.lastname: Chuang
authors.forename: K M
authors.initials: KM
authors.lastname: Lam
authors.forename: H F
authors.initials: HF
authors.lastname: Kung
authors.forename: J M
authors.initials: JM
authors.lastname: Wang
authors.forename: B I
authors.initials: BI
authors.lastname: Osburn
authors.forename: R Y
authors.initials: RY
authors.lastname: Chuang
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology; D000818:Animals; D002464:Cell Migration Inhibition; D054407:Chemokine CCL4; D018946:Chemokine CCL5 / Q000037:antagonists & inhibitors / Q000494:pharmacology; D018925:Chemokines / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D002634:Chemotaxis, Leukocyte / Q000187:drug effects*; D006801:Humans; D016209:Interleukin-8 / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008253:Macaca mulatta; D019402:Macrophage Inflammatory Proteins / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008297:Male; D009000:Monocytes / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D009020:Morphine / Q000494:pharmacology; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D017450:Receptors, Opioid, mu / Q000819:agonists* / Q000037:antagonists & inhibitors
chemical_list: D000701:Analgesics, Opioid; D054407:Chemokine CCL4; D018946:Chemokine CCL5; D018925:Chemokines; D016209:Interleukin-8; D019402:Macrophage Inflammatory Proteins; D017450:Receptors, Opioid, mu; D009020:Morphine