Lipopolysaccharide and a social stressor influence behaviour, corticosterone and cytokine levels: divergent actions in cyclooxygenase-2 deficient mice and wild type controls.
Administration of the endotoxin, lipopolysaccharide (LPS) diminished motor activity and increased plasma corticosterone as well as circulating levels of interleukin-1beta (IL-1beta), IL-6, tumor necrosis-factor-alpha (TNF-alpha) and IL-10. Among cyclooxygenase-2 (COX-2) knockout mice the behavioural, corticosterone and cytokine variations promoted by LPS were moderately (home cage activity, corticosterone, TNF-alpha) or largely (IL-6) reduced. However, if mice were exposed to a psychosocial stressor (social disruption associated with grouping mice with novel cage-mates after a period of isolation) coupled with LPS treatment, then the effects of the COX-2 deletion were absent, or there was a synergistic or additive elevation apparent (e.g., in the case of TNF-alpha, IL-6 and corticosterone). Evidently, COX-2 deletion may have either pro- or anti-inflammatory actions, depending upon the psychosocial context in which immune activation occurs.
Hayley
Shawn
S
Institute of Neuroscience, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6. shayley@ccs.carleton.ca
Mangano
Emily
E
Strickland
Michael
M
Anisman
Hymie
H
D000818:Animals; D001522:Behavior, Animal; D003345:Corticosterone / Q000096:biosynthesis* / Q000097:blood; D051546:Cyclooxygenase 2 / Q000172:deficiency* / Q000235:genetics / Q000502:physiology; D016207:Cytokines / Q000096:biosynthesis* / Q000097:blood; D006799:Housing, Animal; D018836:Inflammation Mediators / Q000502:physiology; D015850:Interleukin-6 / Q000097:blood; D008070:Lipopolysaccharides / Q000008:administration & dosage*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009043:Motor Activity / Q000276:immunology; D012934:Social Isolation / Q000523:psychology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D015854:Up-Regulation / Q000276:immunology; D000093242:Interleukin-6 Inhibitors
D003345:Corticosterone; D051546:Cyclooxygenase 2; D016207:Cytokines; D018836:Inflammation Mediators; D015850:Interleukin-6; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D000093242:Interleukin-6 Inhibitors; C077623:Ptgs2 protein, mouse