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Please use this identifier to cite or link to this item: http://acervodigital.unesp.br/handle/11449/2631
Title: 
Involvement of serotoninergic receptors in the anteroventral preoptic region on hypoxia-induced hypothermia
Author(s): 
Institution: 
  • Universidade Estadual Paulista (UNESP)
  • St Josephs Hosp
  • Med Ctr
  • Universidade de São Paulo (USP)
ISSN: 
0006-8993
Abstract: 
Hypoxia causes a regulated decrease in body temperature (Tb). There is circumstantial evidence that the neurotransmitter serotonin (5-HT) in the anteroventral preoptic region (AVPO) mediates this response. However, which 5-HT receptor(s) is (are) involved in this response has not been assessed. Thus, we investigated the participation of the 5-HT receptors (5-HT(1), 5-HT(2), and 5-HT(7)) in the AVPO in hypoxic hypothermia. To this end, Tb of conscious Wistar rats was monitored by biotelemetry before and after intra-AVPO microinjection of methysergide (a 5-HT(1) and 5-HT(2) receptor antagonist, 0.2 and 2 mu g/100 nL), WAY-100635 (a 5-HT(1A) receptor antagonist, 0.3 and 3 mu g/100 nL), and SB-269970 (a 5-HT(7) receptor antagonist, 0.4 and 4 mu/100 nL), followed by 60 min of hypoxia exposure (7% O(2)). During the experiments, the mean chamber temperature was 24.6 +/- 0.7 degrees C (mean +/- SE) and the mean room temperature was 23.5 +/- 0.8 degrees C (mean +/- SE). Intra-AVPO microinjection of vehicle or 5-HT antagonists did not change Tb during normoxic conditions. Exposure of rats to 7% of inspired oxygen evoked typical hypoxia-induced hypothermia after vehicle microinjection, which was not affected by both doses of methysergide. However, WAY-100635 and SB-269970 treatment attenuated the drop in Tb in response to hypoxia. The effect was more pronounced with the 5-HT7 antagonist since both doses (0.4 and 4 mu g/0.1 mu L) were capable of attenuating the hypothermic response. As to the 5-HT(1A) antagonist, the attenuation of hypoxia-induced hypothermia was only observed at the higher dose. Therefore, the present results are consistent with the notion that 5-HT acts on both 5-HT(1A) and 5-HT7 receptors in the AVPO to induce hypothermia, during hypoxia. (c) 2005 Elsevier B.V All rights reserved.
Issue Date: 
17-May-2005
Citation: 
Brain Research. Amsterdam: Elsevier B.V., v. 1044, n. 1, p. 16-24, 2005.
Time Duration: 
16-24
Publisher: 
Elsevier B.V.
Keywords: 
  • serotonin
  • Hypoxia
  • hypothermia
  • preoptic area
  • then noregulation
Source: 
http://dx.doi.org/10.1016/j.brainres.2005.02.069
URI: 
Access Rights: 
Acesso restrito
Type: 
outro
Source:
http://repositorio.unesp.br/handle/11449/2631
Appears in Collections:Artigos, TCCs, Teses e Dissertações da Unesp

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