title: Effect of the activation of central 5-HT2C receptors by the 5-HT2C agonist mCPP on blood pressure and heart rate in rats.
abstract: In the present study we investigated the role of central 5-HT2C receptors in the control of blood pressure and heart rate in non-stressed and stressed, adult, male, Wistar rats. Third ventricle injections of the 5-HT2C agonist mCPP elicited a significant increase in blood pressure in non-stressed animals. The initial period of this hypertensive response (10-30 min after mCPP administration) was accompanied by baroreflex-mediated bradycardia, while after this period the coexistence of hypertension and tachycardia was observed. These cardiovascular effects promoted by the central administration of mCPP were blocked by pretreatment with the 5-HT2C antagonist, SDZ SER 082. The administration of SDZ SER 082 alone induced no significant changes in blood pressure or heart rate. The pharmacological stimulation of central 5-HT2C receptors by mCPP did not change the hypertensive or tachycardic responses induced by restraint stress. Conversely, the blockade of central 5-HT2C receptors by SDZ SER 082 blunted stress-induced hypertension without modifying stress-induced tachycardia. It is concluded that the activation of central 5-HT2C receptors induces hypertension in non-stressed rats and that the normal function of these receptors is essential for the rise in blood pressure that occurs in the course of restraint stress.
authors.affiliation: Life Sciences Department, Bahia State University, 41195-001 Salvador, Bahia, Brazil.
authors.forename: Hilda Silva
authors.initials: HS
authors.lastname: Ferreira
authors.forename: Elenilda
authors.initials: E
authors.lastname: Oliveira
authors.forename: Thiallan Nery
authors.initials: TN
authors.lastname: Faustino
authors.forename: Emilio de Castro E
authors.initials: Ede C
authors.lastname: Silva
authors.forename: Josmara Bartolomei
authors.initials: JB
authors.lastname: Fregoneze
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D006339:Heart Rate / Q000187:drug effects* / Q000502:physiology; D008297:Male; D010879:Piperazines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D044405:Receptor, Serotonin, 5-HT2C / Q000378:metabolism; D058826:Serotonin 5-HT2 Receptor Agonists; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*
chemical_list: D010879:Piperazines; D044405:Receptor, Serotonin, 5-HT2C; D058826:Serotonin 5-HT2 Receptor Agonists; D017366:Serotonin Receptor Agonists; C015068:1-(3-chlorophenyl)piperazine