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Cytokine-induced antinociception mediated by opioids released from immune cells
S191
CYTOKINE-INDUCED ANTINOCICEPTION MEDIATED BY OPIOIDS RELF~%BED FROM IMMUNE CELLS ~ e i n C, Sch~fer M, Carter L, *Czlonkowski A, Mousa S, Epplen C. Dep. of Anesthesiology, Johns Hopkins ~niversity and NIH/NIDA, Baltimore, MD 21287-5354, USA, Dep. of Neuropharmacology and --Neuroimmunology, MaxPlanck-Institut f~r Psychiatrie, 8033 Martinsried, Germany Abstraot: Immune cell-derived opioid peptides (1,2) apparently play an important role in the local inhibition of pain within inflamed tissue of animals and humans (3,4,5). Proopiomelanocortin- and proenkephalin-mRNA's, as well as B-endorphin (END) and [Met]enkephalin (and small amounts of dynorphin) are detectable within inflamed subcutaneous tissue (3,6,7). These peptides are localized in T- and B-lymphocytes, monocytes and macrophages. Upon local administration of cytokines, inflammatory pain can be attenuated. This effect is reversible by immunosuppression with cyclosporine A (CsA), by passive immunization with antibodies against END, and by opioid antagonists. These findings are consistent with the notion that cytokines release END from resident immune cells, which subsequently activates opioid receptors on sensory nerves (3,8,9) to inhibit nociception. Methods: Male Wistar rats received an intraplantar (i.pl.) injection of killed mycobacteria (Freund's adjuvant) and developed unilateral inflammation of the hindpaw. Four days later their reaction to painful stimulation was tested by determining their paw withdrawal threshold (PWT) upon application of incremental pressure to the hindpaws (3,6). Interleukin-l-beta (IL-1), IL-6 and Tumor Necrosis Factor (TNF) were given i.pl. or intravenously (i.v.) and their effects upon PWT were assessed. Reversibility of these effects by IL-receptor antagonist (ILra), CsA, anti-END, naloxone and receptor-selective opioid antagonists was tested. In separate experiments popliteal and axillary lymph nodes were removed and ground in a dissociation sieve to prepare cell suspensions of approximately 0.1 to 0.5 x 10 cells/m1. These were incubated for 10 min with various concentrations of IL-1 with and without ILra, centrifuged, and END levels in supernatants assessed by radioimmunoassay. Results: Local (i.pl.) but not systemic (i.v.) application of all three cytokines produced dose-dependent increases of PWT in inflamed but not in noninflamed paws. These effects were abolished by systemic pretreatment with CsA. IL-l-induced PWT elevation was reversible by concomitant i.pl. application of ILra. Antinociceptive effects of all three cytokines were attenuated by i.pl. anti-END, naloxone and the mu-antagonist CTOP. The deltaantagonist ICI 174,864 inhibited the effects of IL-I and TNF, the kappa-antagonist nor-BNI inhibited those of IL-1 and IL-6. IL-1 produced dose-dependent and ILra-reversible END release from immune cell suspensions in vitro. Conclusions: All three cytokines produce peripherally mediated antinociception in inflamed tissue. The most likely mechanism is a release of opioid peptides from immune cells and the subsequent activation of opioid receptors on sensory nerves. END and mureceptors play a major role. The fact that delta- and kappareceptors are differentially activated suggests that B a c h cytokine releases a different combination of opioid peptides. References: i. N.E.S. Sibinga and A. Goldstein
(1988) Annu Rev Immunol 6, 219-
S192
249 C.J. H e i j n e n et al. (1991) I m m u n o l R e v 119, 41-63 C. S t e i n et al. (1990) Proc Natl A c a d Sci 87, 5 9 3 5 - 5 9 3 9 M. S c h ~ f e r et al. (1993) Soc N e u r o s c i Abstr, in p r e s s C. S t e i n et al. (1993) Lancet, in p r e s s R. P r z e w l o c k i et al. (1992) N e u r o s c i e n c e 48, 4 9 1 - 5 0 0 A.H.S. H a s s a n et al. (1992) N e u r o s c i L e t t 140, 85-88 L. B a r t h o et al. (1990) N a u n y n S c h m i e d e b e r g ' s A r c h P h a r m a c o l 342, 6 6 6 - 6 7 0 9. A.H.S. H a s s a n et al. (1993) N e u r o s c i e n c e 55, 1 8 5 - 1 9 5 2. 3. 4. 5. 6. 7. 8.
CYTOKINE-INDUCED ANTINOCICEPTION MEDIATED BY OPIOIDS RELF~%BED FROM IMMUNE CELLS ~ e i n C, Sch~fer M, Carter L, *Czlonkowski A, Mousa S, Epplen C. Dep. of Anesthesiology, Johns Hopkins ~niversity and NIH/NIDA, Baltimore, MD 21287-5354, USA, Dep. of Neuropharmacology and --Neuroimmunology, MaxPlanck-Institut f~r Psychiatrie, 8033 Martinsried, Germany Abstraot: Immune cell-derived opioid peptides (1,2) apparently play an important role in the local inhibition of pain within inflamed tissue of animals and humans (3,4,5). Proopiomelanocortin- and proenkephalin-mRNA's, as well as B-endorphin (END) and [Met]enkephalin (and small amounts of dynorphin) are detectable within inflamed subcutaneous tissue (3,6,7). These peptides are localized in T- and B-lymphocytes, monocytes and macrophages. Upon local administration of cytokines, inflammatory pain can be attenuated. This effect is reversible by immunosuppression with cyclosporine A (CsA), by passive immunization with antibodies against END, and by opioid antagonists. These findings are consistent with the notion that cytokines release END from resident immune cells, which subsequently activates opioid receptors on sensory nerves (3,8,9) to inhibit nociception. Methods: Male Wistar rats received an intraplantar (i.pl.) injection of killed mycobacteria (Freund's adjuvant) and developed unilateral inflammation of the hindpaw. Four days later their reaction to painful stimulation was tested by determining their paw withdrawal threshold (PWT) upon application of incremental pressure to the hindpaws (3,6). Interleukin-l-beta (IL-1), IL-6 and Tumor Necrosis Factor (TNF) were given i.pl. or intravenously (i.v.) and their effects upon PWT were assessed. Reversibility of these effects by IL-receptor antagonist (ILra), CsA, anti-END, naloxone and receptor-selective opioid antagonists was tested. In separate experiments popliteal and axillary lymph nodes were removed and ground in a dissociation sieve to prepare cell suspensions of approximately 0.1 to 0.5 x 10 cells/m1. These were incubated for 10 min with various concentrations of IL-1 with and without ILra, centrifuged, and END levels in supernatants assessed by radioimmunoassay. Results: Local (i.pl.) but not systemic (i.v.) application of all three cytokines produced dose-dependent increases of PWT in inflamed but not in noninflamed paws. These effects were abolished by systemic pretreatment with CsA. IL-l-induced PWT elevation was reversible by concomitant i.pl. application of ILra. Antinociceptive effects of all three cytokines were attenuated by i.pl. anti-END, naloxone and the mu-antagonist CTOP. The deltaantagonist ICI 174,864 inhibited the effects of IL-I and TNF, the kappa-antagonist nor-BNI inhibited those of IL-1 and IL-6. IL-1 produced dose-dependent and ILra-reversible END release from immune cell suspensions in vitro. Conclusions: All three cytokines produce peripherally mediated antinociception in inflamed tissue. The most likely mechanism is a release of opioid peptides from immune cells and the subsequent activation of opioid receptors on sensory nerves. END and mureceptors play a major role. The fact that delta- and kappareceptors are differentially activated suggests that B a c h cytokine releases a different combination of opioid peptides. References: i. N.E.S. Sibinga and A. Goldstein
(1988) Annu Rev Immunol 6, 219-
S192
249 C.J. H e i j n e n et al. (1991) I m m u n o l R e v 119, 41-63 C. S t e i n et al. (1990) Proc Natl A c a d Sci 87, 5 9 3 5 - 5 9 3 9 M. S c h ~ f e r et al. (1993) Soc N e u r o s c i Abstr, in p r e s s C. S t e i n et al. (1993) Lancet, in p r e s s R. P r z e w l o c k i et al. (1992) N e u r o s c i e n c e 48, 4 9 1 - 5 0 0 A.H.S. H a s s a n et al. (1992) N e u r o s c i L e t t 140, 85-88 L. B a r t h o et al. (1990) N a u n y n S c h m i e d e b e r g ' s A r c h P h a r m a c o l 342, 6 6 6 - 6 7 0 9. A.H.S. H a s s a n et al. (1993) N e u r o s c i e n c e 55, 1 8 5 - 1 9 5 2. 3. 4. 5. 6. 7. 8.