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LPS induces the same prostaglandins (PGs) in warm and cold environments, but thermal responses to PGs strongly depend on ambient temperature (T a )
Author(s) -
Oliveira Cristiane,
Nucci Tatiane B,
Eales Justin,
Dragic Alexander S,
Pan Jennifer,
Patel Shreya,
Pakai Eszter,
Brose Stephen A,
Golovko Michail Y,
Steiner Alexander A,
Romanovsky Andrej A
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.1201.29
Subject(s) - hypothermia , chemistry , lipopolysaccharide , thermoregulation , medicine , endocrinology , prostaglandin f , prostaglandin
Rats respond to iv LPS with a complex thermoregulatory response, which is represented mostly by fever at a neutral T a , but mostly by hypothermia at a subneutral T a . Both the febrile and hypothermic components of this response are mediated by PGs, but the exact mechanism of the fever‐hypothermia switch is unknown. Wistar rats were injected with LPS (10, 100 or 1000 μg/kg iv) at a neutral (30°C) or subneutral (20°C) T a . At 30°C, the febrile components of the response to each LPS dose were more pronounced; at 20°C, the hypothermic components were predominant. At either T a , LPS caused a dose‐depended increase in plasma PGs within all five cascades (PGE 2 , D 2 , F 2á , I 2 and TXB 2 ), whether measured by ELISA or LC/MS/MS. Irrespective of the method, we found no difference in the plasma response of any individual PG to any dose of LPS at 30°C vs 20°C. We then studied thermoregulatory responses of rats to iv PGs (0.8 μmol/kg, administered as albumin complexes) at 30 and 20°C. Only PGE 2 caused a statistically significant fever, and this response was unaffected by T a . Several PGs, including E 2 , D 2 and I 2 , caused hypothermia, and this response was restricted to the subneutral conditions. We conclude that, regardless of T a , LPS causes the same systemic PG response. The fever‐hypothermia switch involves LPS‐induced PGE 2 , D 2 and I 2 causing hypothermia in a subneutral (but not neutral) environment. Support: NS041233 , NS064480 , 11SDG4880051