User:Joilybbi/5-HT3 antogonists drug discovery and development

Mechanism of action
The 5-HT3 receptors are present in several critical sites involved in emesis, including vagal affarents, the STN (solitary tract nucleus), and the area postrema itself. Serotonin is released by the enterochromaffin cells of the small intestine in response to chemotheraputic agents and may stimulate vagal affarents (via 5-HT3 receptors) to initiate the womiting reflex. The 5-HT3 receptor antagonists suppresses vomiting and nausea by inhibiting serotonin binding to the 5-HT3 receptors. The highest concentration of 5-HT3 receptors in the CNS are found in the STN and CTZ (chemo-receptor trigger zone), and 5-HT3 antagonists may also suppress vomiting and nausea by acting at these sites. (GG)