The role of interleukin-6 in stress-induced hyperthermia and emotional behaviour in mice.
Psychological stress influences behaviour as well as autonomic functions such as body temperature. The mechanism that induces hyperthermia during stress is unknown. A recent hypothesis suggests that interleukin-6 (IL-6), an endogenous pyrogen, elevates body temperature during stress. To investigate the role of IL-6 during stress, we measured mRNA levels of IL-6 by quantitative PCR in various tissues 60 min after exposure of mice to open field stress. IL-6 mRNA was elevated in the hypothalamus three-fold and in the pituitary two-fold. However, there was no difference between the increase in body temperature after exposure to 60 min open field stress in wild-type controls (35.2+/-0.6-37.3+/-0.5 degrees C) and IL-6-deficient animals (34.8+/-0.4-37.0+/-0.3 degrees C). In contrast to body temperature, emotional behaviour differed between wild-type controls and IL-6-deficient mice. IL-6-deficient animals showed higher locomotor activity in an open field and lower levels of exploration of the open arms of the elevated plus maze than control animals. These data suggest that IL-6 plays an important role in the control of emotionality, but not in the regulation of body temperature after psychological stress.
Butterweck
Veronika
V
Institute of Pharmacology and Toxicology, Universitaetsklinikum Muenster, Domagkstrasse 12, Muenster 48149, Germany.
Prinz
Simone
S
Schwaninger
Markus
M
D000311:Adrenal Glands / Q000378:metabolism; D018759:Adrenergic Uptake Inhibitors / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D003975:Diazepam / Q000494:pharmacology; D004644:Emotions / Q000502:physiology*; D018757:GABA Modulators / Q000494:pharmacology; D006979:Hyperthermia, Induced / Q000379:methods / Q000523:psychology*; D007031:Hypothalamus / Q000378:metabolism; D007099:Imipramine / Q000494:pharmacology; D015850:Interleukin-6 / Q000235:genetics / Q000502:physiology*; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010902:Pituitary Gland / Q000378:metabolism; D011433:Propranolol / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013154:Spleen / Q000378:metabolism; D013315:Stress, Psychological / Q000503:physiopathology*
D018759:Adrenergic Uptake Inhibitors; D000319:Adrenergic beta-Antagonists; D018757:GABA Modulators; D015850:Interleukin-6; D012333:RNA, Messenger; D011433:Propranolol; D007099:Imipramine; D003975:Diazepam