Table 3.
The two tryptophan hydroxylase isoforms, their location and corresponding physiological and pathological function of central or peripheral serotonin systems
| Tryptophan hydroxylase isoform | |
| TPH1 | TPH2 |
| Location | |
| Enterochromaffin cells, pineal body | Brain |
| Physiological functions of serotonin | |
| Melatonin synthesis | Food intake and body weight |
| Vasoconstriction | Sleep |
| Haemostasis | Behavior |
| Immune system | Mood |
| Intestinal motility | Thermoregulation |
| Serotonin in pathology of diseases | |
| Migraine | Migraine |
| Carcinoid | Neuropsychiatric disorders |
| Obesity | |