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Blockade of 5-HT2A receptors suppresses hyperthermic but not cardiovascular responses to psychosocial stress in rats.
Beig, M I; Baumert, M; Walker, F R; Day, T A; Nalivaiko, E.
Afiliação
  • Beig MI; School of Biomedical Sciences, University of Newcastle, Callaghan, NSW 2038, Australia.
Neuroscience ; 159(3): 1185-91, 2009 Mar 31.
Article em En | MEDLINE | ID: mdl-19356699
ABSTRACT
The aim of this study was to determine whether 5-HT2A receptors mediate cardiovascular and thermogenic responses to acute psychological stresses. For this purpose, adult male Wistar hooded rats instrumented for telemetric recordings of either electrocardiogram (ECG) (n=12) or arterial pressure (n=12) were subjected, on different days, to four 15-min episodes of social defeat. Prior to stress, animals received s.c. injection of the selective 5-HT2A receptor antagonist SR-46349B (trans-4-((3Z)3-[(2-dimethylaminoethyl)oxyimino]-3-(2-fluorophenyl)propen-1-yl)-phenol, hemifumarate) (at doses of 0.3, 1.0 and 3.0 mg/kg) or vehicle. The drug had no effect on basal heart rate or heart rate variability indexes, arterial pressure, and core body temperature. Social defeat elicited significant and substantial tachycardic (347+/-7 to 500+/-7 bpm), pressor (77+/-4 to 97+/-4 mm Hg) and hyperthermic (37.0+/-0.3 to 38.5+/-0.1 degrees C) responses. Blockade of 5-HT2A receptors, at all doses of the antagonist, completely prevented stress-induced hyperthermia. In contrast, stress-induced cardiovascular responses were not affected by the blockade (except small reduction of tachycardia by the highest dose of the drug). We conclude that in rats, 5-HT2A receptors mediate stress-induced hyperthermic responses, but are not involved in the genesis of stress-induced rises in heart rate or arterial pressure, and do not participate in cardiovascular control at rest.
Assuntos

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Fenóis / Antagonistas da Serotonina / Estresse Psicológico / Pressão Sanguínea / Temperatura Corporal / Antagonistas do Receptor 5-HT2 de Serotonina / Fluorbenzenos / Frequência Cardíaca Limite: Animals Idioma: En Revista: Neuroscience Ano de publicação: 2009 Tipo de documento: Article

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Fenóis / Antagonistas da Serotonina / Estresse Psicológico / Pressão Sanguínea / Temperatura Corporal / Antagonistas do Receptor 5-HT2 de Serotonina / Fluorbenzenos / Frequência Cardíaca Limite: Animals Idioma: En Revista: Neuroscience Ano de publicação: 2009 Tipo de documento: Article