Central 5-HT3 receptor stimulation by m-CPBG increases blood glucose in rats

Horm Metab Res. 2002 Feb;34(2):55-61. doi: 10.1055/s-2002-20525.


The aim of the present study was to investigate the role of central 5-HT3 receptors on the control of blood glucose in stressed and non-stressed rats in both fasted and fed states. Adult Wistar male rats had each their third ventricle cannulated 7 days before the experiments. Injections of m-CPBG, a selective 5-HT3 receptor agonist, induced a significant increase in blood glucose in non-stressed rats in both fasted and in fed states. The same procedure was unable to modify stress-induced hyperglycemia. The hyperglycemic effect of m-CPBG central administration was blocked by pretreatment with ondansetron, a specific 5-HT3 receptor antagonist, indicating that the effects here obtained with m-CPBG were a result of its interaction with 5-HT3 receptors. Third ventricle injections of ondansetron alone were not able to modify blood glucose in non-stressed animals and did not change the hyperglycemic responses observed after immobilization stress. We conclude that pharmacological activation of the central 5-HT3 receptor induces a hyperglycemic effect in non-stressed animals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biguanides / pharmacology*
  • Blood Glucose / metabolism*
  • Fasting
  • Food
  • Injections, Intraventricular
  • Kinetics
  • Male
  • Ondansetron / administration & dosage
  • Ondansetron / pharmacology
  • Rats
  • Rats, Wistar
  • Receptors, Serotonin / physiology*
  • Receptors, Serotonin, 5-HT3
  • Restraint, Physical
  • Serotonin Antagonists / administration & dosage
  • Serotonin Antagonists / pharmacology
  • Serotonin Receptor Agonists / pharmacology*
  • Stress, Physiological / blood


  • Biguanides
  • Blood Glucose
  • Receptors, Serotonin
  • Receptors, Serotonin, 5-HT3
  • Serotonin Antagonists
  • Serotonin Receptor Agonists
  • Ondansetron
  • 1-(3-chlorophenyl)biguanide