title: Interaction of supraspinally administered interferon-α with opioid system in the production of antinociception.
abstract: We examined the antinociceptive effect of intracerebroventricularly (i.c.v.) or intrathecally (i.t.) administered of interferon-alpha (IFN-alpha) using the tail-flick analgesic test in mice. IFN-alpha administered i.c.v. but not i.t. showed an antinociceptive effect in a dose-dependent manner (0.05-5 microg). To examine the possible interaction with brain opioid system, IFN-alpha was cotreated with either beta-endorphin or morphine. Combined i.c.v. treatment of IFN-alpha (0.5 microg) with beta-endorphin (0.125 microg) caused a synergistic antinociceptive effect. And also, the synergistic interaction maintained at least for 60 min after the co-treatment of IFN-alpha and beta-endorphin. However, the combined treatment of i.t. IFN-alpha with i.c.v. beta-endorphin showed neither an additive nor a synergistic antinociceptive profile. The i.c.v. co-treatment of IFN-alpha with morphine (0.2 microg) showed an additive antinociceptive effect only. The i.t. administered IFN-alpha did not show any additive antinociceptive effect when morphine was administered i.c.v. simultaneously. Taken together, our results suggest that supraspinally co-administered IFN-alpha and beta-endorphin may produce antinociception synergistically via interaction of IFN-alpha with supraspinal beta-endorphin sensitive opioid receptors.
authors.affiliation: Institute of Natural Medicine, Hallym University, Chuncheon, Korea.
authors.forename: Jin-Koo
authors.initials: JK
authors.lastname: Lee
authors.forename: Soo-Hyun
authors.initials: SH
authors.lastname: Park
authors.forename: Yun-Beom
authors.initials: YB
authors.lastname: Sim
authors.forename: Jun-Sub
authors.initials: JS
authors.lastname: Jung
authors.forename: Hong-Won
authors.initials: HW
authors.lastname: Suh
mesh_terms: D000700:Analgesics / Q000008:administration & dosage*; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D000818:Animals; D004357:Drug Synergism; D007278:Injections, Spinal; D016898:Interferon-alpha / Q000008:administration & dosage*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010147:Pain Measurement / Q000187:drug effects* / Q000379:methods; D011957:Receptors, Opioid / Q000819:agonists* / Q000378:metabolism; D001615:beta-Endorphin / Q000008:administration & dosage
chemical_list: D000700:Analgesics; D000701:Analgesics, Opioid; D016898:Interferon-alpha; D011957:Receptors, Opioid; D001615:beta-Endorphin