Electrical stimulation of the vagus nerve modulates the histamine content of mast cells in the rat jejunal mucosa.

Mast cells are best known for their participation in allergic reactions. However, a number of recent studies suggest that mast cells are subject to nervous control. In the gut mucosa, mast cells are intimately associated with nerves, and the psychologically conditioned release of RMCP II (a mucosal mast cell-derived mediator) has been reported. These data suggest the potential for CNS regulation of intestinal mucosal mast cells. In this study, we stimulated the cervical vagi and found an increased histamine content in mucosal mast cells, without apparent degranulation. Furthermore, these changes could be prevented by subdiaphragmatic vagotomy. These data support the potential for intestinal mucosal mast cell regulation by the central nervous system and suggest modulation of mast cells without degranulation.