Circulating serotonin is produced in the duodenum by enterochromaffin cells, specialized endocrine cells in the epithelia lining the gut, and functions within a specialized neuroendocrine network.

Immunolabelling showed specific colocalisation of receptors with EEC mediators PYY and GLP-1 (L-cells) or 5-HT (enterochromaffin cells). We exposed isolated proximal colonic mucosa to specific ...

Enterochromaffin cells that contain large amounts of serotonin are mostly located in the distal appendix. Serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) could therefore be a marker for acute ...