UCL logo

UCL Discovery

UCL home » Library Services » Electronic resources » UCL Discovery

Evidence for a role for central 5-HT2B as well as 5-HT2A receptors in cardiovascular regulation in anaesthetized rats

Knowles, ID; Ramage, AG; (1999) Evidence for a role for central 5-HT2B as well as 5-HT2A receptors in cardiovascular regulation in anaesthetized rats. BRIT J PHARMACOL , 128 (3) 530 - 542.

Full text not available from this repository.

Abstract

1 The effects of injections i.c.v. of quipazine, (2 mu mol kg(-1)) and 1-(2,5-di-methoxy-4-iodophenyl)-2-aminopropane (DOT; 2 mu mol kg(-1)) on renal sympathetic and phrenic nerve activity, mean arterial blood pressure (MAP) and heart rate were investigated in alpha-chloralose anaesthetized rats pretreated with a peripherally acting 5-HT2 receptor antagonist.2 Quipazine or DOI caused a rise in MAP which was associated with a tachycardia and renal sympathoinhibition in rats pretreated (i.c.v.) with the antagonist vehicle 10% PEG. These effects of quipazine were completely blocked by pretreatment with cinanserin (a 5-HT2 receptor antagonist) and attenuated by spiperone (a 5-HT2A receptor antagonist). However, pretreatment with SB200646A (a 5-HT2B/2C receptor antagonist) only blocked the sympathoinhibition, while pretreatment with SB204741 (a 5-HT2B receptor antagonist) reversed the sympathoinhibition to excitation as it also did for DOI. Quipazine also caused renal sympathoexcitation in the presence (i.v.) of a vasopressin V-1 receptor antagonist.3 Injection (i.v.) of the V-1 receptor antagonist at the peak presser response evoked by quipazine alone and in the presence of SB204741 caused an immediate fall in MAP. For quipazine alone the renal sympathoinhibition was slowly reversed to an excitation, while the renal sympathoexcitation observed in the presence of SB204741 was potentiated. In both, the quipazine-evoked tachycardia was unaffected.4 The data indicate that cardiovascular responses caused by i.c.v. quipazine and DOT are primarily due to activation of central 5-HT2A receptors, which causes the release of vasopressin and a tachycardia. This released vasopressin appears to suppress a 5-HT2A receptor-evoked central increase in sympathetic outflow, which involves the activation of central 5-HT2B receptors indirectly by the released vasopressin.

Type: Article
Title: Evidence for a role for central 5-HT2B as well as 5-HT2A receptors in cardiovascular regulation in anaesthetized rats
Keywords: 5-HT2B receptors, 5-HT2A receptors, blood pressure, sympathetic, nerve activity, vasopressin V-1-receptors, quipazine, DOI, SB204741, SB200646A, spiperone, CENTRAL-NERVOUS-SYSTEM, ANESTHETIZED RATS, SUBFORNICAL ORGAN, ANGIOTENSIN-II, SEROTONIN, AGONIST, VASOPRESSIN, ACTIVATION, QUIPAZINE, FOREBRAIN
UCL classification: UCL > Provost and Vice Provost Offices
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences
URI: http://discovery.ucl.ac.uk/id/eprint/166023
Downloads since deposit
0Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item