Effect of the activation of central 5-HT2C receptors by the 5-HT2C agonist mCPP on blood pressure and heart rate in rats

Brain Res. 2005 Apr 8;1040(1-2):64-72. doi: 10.1016/j.brainres.2005.01.054.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Pressure / drug effects*
  • Blood Pressure / physiology
  • Heart Rate / drug effects*
  • Heart Rate / physiology
  • Male
  • Piperazines / pharmacology*
  • Rats
  • Rats, Wistar
  • Receptor, Serotonin, 5-HT2C / metabolism
  • Serotonin 5-HT2 Receptor Agonists*
  • Serotonin Receptor Agonists / pharmacology*

Substances

  • Piperazines
  • Receptor, Serotonin, 5-HT2C
  • Serotonin 5-HT2 Receptor Agonists
  • Serotonin Receptor Agonists
  • 1-(3-chlorophenyl)piperazine