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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Nitric oxide and fever: immune-to-brain signaling vs. thermogenesis in chicks

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Dantonio, Valter [1, 2] ; Batalhao, Marcelo E. [3] ; Fernandes, Marcia H. M. R. [4] ; Komegae, Evilin N. [5] ; Buqui, Gabriela A. [6] ; Lopes, Norberto P. [6] ; Gargaglioni, Luciane H. [1, 2] ; Carnio, Evelin C. [3] ; Steiner, Alexandre A. [5] ; Bicego, Kenia C. [1, 2]
Total Authors: 10
[1] Sao Paulo State Univ, Dept Anim Morphol & Physiol, Coll Agr & Vet Sci, Sao Paulo - Brazil
[2] Natl Inst Sci & Technol Comparat Physiol INCT Fis, Sao Paulo - Brazil
[3] Univ Sao Paulo, Nursing Sch Ribeirao Preto, Sao Paulo - Brazil
[4] Sao Paulo State Univ, Dept Anim Sci, Coll Agr & Vet Sci, Sao Paulo - Brazil
[5] Univ Sao Paulo, Inst Biomed Sci, Dept Immunol, Sao Paulo, SP - Brazil
[6] Univ Sao Paulo, Fac Pharmaceut Sci Ribeirao Preto, Dept Chem & Phys, Nucleo Pesquisa Prod Nat & Sintet, Sao Paulo - Brazil
Total Affiliations: 6
Document type: Journal article
Web of Science Citations: 3

Nitric oxide (NO) plays a role in thermogenesis but does not mediate immune-to-brain febrigenic signaling in rats. There are suggestions of a different situation in birds, but the underlying evidence is not compelling. The present study was designed to clarify this matter in 5-day-old chicks challenged with a low or high dose of bacterial LPS. The lower LPS dose (2 mu g/kg im) induced fever at 3-5 h postinjection, whereas 100 mu g/kg im decreased core body temperature (T-c) (at 1 h) followed by fever (at 4 or 5 h). Plasma nitrate levels increased 4 h after LPS injection, but they were not correlated with the magnitude of fever. The NO synthase inhibitor (NG-nitro-L-arginine methyl ester, L-NAME; 50 mg/kg im) attenuated the fever induced by either dose of LPS and enhanced the magnitude of the Tc reduction induced by the high dose in chicks at 31-32 degrees C. These effects were associated with suppression of metabolic rate, at least in the case of the high LPS dose. Conversely, the effects of L-NAME on Tc disappeared in chicks maintained at 35-36 degrees C, suggesting that febrigenic signaling was essentially unaffected. Accordingly, the LPS-induced rise in the brain level of PGE(2) was not affected by L-NAME. Moreover, L-NAME augmented LPS-induced huddling, which is indicative of compensatory mechanisms to run fever in the face of attenuated thermogenesis. Therefore, as in rats, systemic inhibition of NO synthesis attenuates LPS-induced fever in chicks by affecting thermoeffector activity and not by interfering with immune-to-brain signaling. This may constitute a conserved effect of NO in endotherms. (AU)

FAPESP's process: 14/50265-3 - Distribution and metabolism of natural and synthetic xenobiotics: from the comprehension of reactional process to tissue imaging generation
Grantee:Norberto Peporine Lopes
Support type: BIOTA-FAPESP Program - Thematic Grants
FAPESP's process: 13/13386-4 - Putative role of nitric oxide and greline as mediators/modulators of the febrile response in broiler chicks
Grantee:Kênia Cardoso Bícego
Support type: Regular Research Grants
FAPESP's process: 12/03831-8 - Linking energy balance to systemic inflammation: role of leptin
Grantee:Alexandre Alarcon Steiner
Support type: Research Grants - Young Investigators Grants
FAPESP's process: 14/13586-6 - Effect on ghrelin on growth hormone/insuline-like growth factor in rats submmited to endotoxemia
Grantee:Evelin Capellari Cárnio
Support type: Regular Research Grants
FAPESP's process: 12/19966-0 - Cardiorespiratory pattern and awake-sleep state in male and female rats exposed to fluoxetine during prenatal period
Grantee:Luciane Helena Gargaglioni Batalhão
Support type: Regular Research Grants