Serotonin upregulates the activity of phagocytosis through 5-HT1A receptors.

1 In this study, we investigated whether serotonin could regulate the in vitro activity of phagocytosis through 5-hydroxytryptamine or serotonin (5-HT(1A)) receptors. 2 Mouse peritoneal macrophages were cultured with serotonin and the activity of phagocytosis was assessed by the uptake of zymosan and latex particles added to the culture media. Specific binding of [(3)H]8-OH-DPAT and immunohistochemistry using an affinity-purified anti-5-HT(1A)-receptor antibody were assayed in the macrophages.