Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.13/808641

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Title
Blockade of 5-HT2A receptors suppresses hyperthermic but not cardiovascular responses to psychosocial stress in rats
Author/Creator
Beig, M. I.;  Baumert, M.;  Walker, F. R.;  Day, T. A.;  Nalivaiko, E.
Institution
The University of Newcastle. Faculty of Health, School of Biomedical Sciences and Pharmacy
Description
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 °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.
Relation
Neuroscience Vol. 159, Issue 3, p. 1185-1191
Publisher Link
http://dx.doi.org/10.1016/j.neuroscience.2009.01.038
Date
2009
Publisher
Elsevier
Keyword(s)
social defeat;  heart rate;  arterial pressure;  core body temperature;  5-HT
Resource Type
journal article
Identifier
http://hdl.handle.net/1959.13/808641
Identifier
ISSN:0306-4522
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Subject
"Neuroscience"
 
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