title: Changes in pain behavior induced by formalin, substance P, glutamate and pro-inflammatory cytokines in immobilization-induced stress mouse model.
abstract: In the present study, we examined the change of pain behaviors induced by formalin injected subcutaneously (s.c.) into the hind paw, or substance P (SP), glutamate, and pro-inflammatory cytokines (TNF-alpha, IL-1beta, and IFN-gamma) injected intrathecally (i.t.) in the mouse immobilization stress model. The mouse was restrained either once for 1h or five times for 5 days (once/day). In the formalin test, a single immobilization stress attenuated pain behaviors (licking, biting or scratching) in the second phase, while it had no effect on the pain behaviors revealed during the first phase. In addition, repeated immobilization stress attenuated pain behaviors revealed during the second phase but not in the first phase. A single as well as repeated immobilization stress decreased pain behaviors induced by substance P i.t. injection, but there were no significant changes in the glutamate test. In the pro-inflammatory cytokine pain model, a single immobilization stress decreased the pain behaviors induced by TNF-alpha, IL-1beta administered i.t. but not by IFN-gamma administered i.t. Moreover, a mouse applied with repeated immobilization stress did not show any changes in pain behaviors elicited by pro-inflammatory cytokines (TNF-alpha, IL-1beta and IFN-gamma) compared to the control group. These results suggest that a single and repeated immobilization stress differentially affects such nociceptive processing induced by formalin, SP, glutamate and pro-inflammatory cytokines in different manners.
authors.affiliation: Department of Pharmacology and Institute of Natural Medicine, College of Medicine, Hallym University, 1 Okcheon-Dong, Chuncheon, Gangwon-Do 200-702, South Korea.
authors.forename: Young-Jun
authors.initials: YJ
authors.lastname: Seo
authors.forename: Min-Soo
authors.initials: MS
authors.lastname: Kwon
authors.forename: Eon-Jeong
authors.initials: EJ
authors.lastname: Shim
authors.forename: Soo-Hyun
authors.initials: SH
authors.lastname: Park
authors.forename: Ok-Sun
authors.initials: OS
authors.lastname: Choi
authors.forename: Hong-Won
authors.initials: HW
authors.lastname: Suh
mesh_terms: D000698:Analgesia / Q000379:methods; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D016207:Cytokines / Q000009:adverse effects; D004195:Disease Models, Animal; D018698:Glutamic Acid / Q000009:adverse effects; D018836:Inflammation Mediators / Q000009:adverse effects; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009619:Nociceptors / Q000187:drug effects / Q000502:physiology; D010146:Pain / Q000139:chemically induced / Q000503:physiopathology* / Q000523:psychology*; D010147:Pain Measurement / Q000187:drug effects; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology*; D012149:Restraint, Physical; D013315:Stress, Psychological / Q000503:physiopathology* / Q000523:psychology*; D013373:Substance P / Q000009:adverse effects
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; D013373:Substance P; D018698:Glutamic Acid