Ondansetron, a selective 5-HT3 antagonist, antagonizes methamphetamine-induced anorexia in mice.

Abstract

Effects of some selective serotonergic (5-HT) antagonists on methamphetamine-induced anorexia were investigated in male mice. The least possible dose of methamphetamine alone that caused significant anorectic activity was 11 micromolkg(-1), i.p. (2 mgkg(-1)). Various doses of some selective serotonergic receptor antagonists were administered half an hour before the above mentioned dose of methamphetamine. Methiothepin potentiated, whereas NAN-190, methysergide, mianserin and ondansetron antagonized methamphetamine-induced anorectic activity. The least possible doses of these antagonists which modified methamphetamine-induced anorexia were as follows: methiothepin (1.1 micromolkg(-1), i.p.), NAN-190 (4.2 micromolkg(-1), i.p.), methysergide (2.1 micromolkg(-1), i.p.), mianserin (3.3 micromolkg(-1), i.p.) and ondansetron (0.003 micromolkg(-1), i.p.). The serotonergic antagonists at the above mentioned doses did not modify the food intake of animals not treated with methamphetamine, except for methiothepin, which produced a significant reduction, and mianserin, which produced a significant increase in food intake. The results of the present study indicated that the anorectic activity induced by methamphetamine is related to the interactions of methamphetamine with 5-HT receptor. Since a very small dose (0.003 micromolkg(-1)) of ondansetron (the 5-HT(3) antagonist), as compared with the other antagonists used in this study, antagonized the anorexia induced by methamphetamine, the 5-HT(3) receptor is likely to be the site for this interaction.

• Authors: O T Ginawi, A A Al-Majed, A K Al-Suwailem
• Journal: Pharmacological research (Pharmacol Res) Vol. 51 Issue 3 Pg. 255-9 (Mar 2005) ISSN: 1043-6618 [Print] Netherlands
• PMID: 15661576 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Receptors, Serotonin, 5-HT3
• Serotonin 5-HT3 Receptor Antagonists
• Serotonin Antagonists
• Methamphetamine
• Ondansetron

Topics

• Animals
• Anorexia (chemically induced, prevention & control)
• Eating (drug effects, physiology)
• Male
• Methamphetamine (antagonists & inhibitors, toxicity)
• Mice
• Ondansetron (pharmacology)
• Receptors, Serotonin, 5-HT3 (physiology)
• Serotonin 5-HT3 Receptor Antagonists
• Serotonin Antagonists (pharmacology)