Journal article
Anteroventral third ventricle lesions attenuate pressor responses to serotonin in in anesthetized rats
Brain research, Vol.714(1), pp.104-110
04/01/1996
DOI: 10.1016/0006-8993(95)01503-5
PMID: 8861614
Abstract
When administered intravenously, serotonin (5-hydroxytryptamine; 5-HT) evokes a triphasic blood pressure response, consisting of the Bezold-Jarisch-associated depressor response, a pressor action, and long-lasting depressor response. Because the pressor response may, in part, be caused by central nervous system (CNS) activation by 5-HT, we predicted that destruction of the anteroventral third ventricle (AV3V) region, an area rich in 5-HT receptors, would attenuate increases in blood pressure to intravenous 5-HT. In anesthetized sham-lesioned and AV3V-lesioned Sprague-Dawley rats, we measured mean arterial pressure (MAP), heart rate (HR), and lumbar sympathetic nerve activity (SNA) to increasing bolus doses of intravenous 5-HT (1, 2.5, 5, 10, 25 μg/kg), before and after blockade of bradycardia using methylatropine (200 μg/kg). In all rats, bolus injections of 5-HT elicited bradycardia accompanied by a fall in lumbar SNA and an initial hypotension followed by a pressor response and a longer lasting hypotensive response. The bradycardia, reduction in lumbar SNA, and both depressor responses were equivalent in sham-lesioned and AV3V-lesioned groups. Importantly, AV3V lesions attenuated pressor responses to increasing doses of 5-HT (3 ± 1, 6 ± 4, 6 ± 4, 17 ± 4, 35 ± 3 mmHg) compared to sham-lesioned controls (6 ± 3, 16 ± 7, 33 ± 5, 54 ± 4, 51 ± 6 mmHg;
P < 0.0001). This attenuation was conserved following blockade of bradycardia with methylatropine (
P < 0.01). In summary, pressor responses to intravenous 5-HT are diminished by AV3V lesions. These data indicate that the pressor component of the blood pressure response to intravenous 5-HT is partly dependent upon interaction with the CNS.
Details
- Title: Subtitle
- Anteroventral third ventricle lesions attenuate pressor responses to serotonin in in anesthetized rats
- Creators
- Martin S MuntzelStephen J LewisAlan Kim Johnson
- Resource Type
- Journal article
- Publication Details
- Brain research, Vol.714(1), pp.104-110
- Publisher
- Elsevier B.V
- DOI
- 10.1016/0006-8993(95)01503-5
- PMID
- 8861614
- ISSN
- 0006-8993
- eISSN
- 1872-6240
- Language
- English
- Date published
- 04/01/1996
- Academic Unit
- Psychological and Brain Sciences; Neuroscience and Pharmacology; Health and Human Physiology
- Record Identifier
- 9984213415202771
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