Hypersensitivity to ovalbumin induces chronic intestinal dysmotility and increases the number of intestinal mast cells.

Undiagnosed food allergies have been proposed as possible causes of promoting and perpetuating irritable bowel syndrome . Our aim was to find out if sensitization could induce chronic functional motor disturbances in the intestine and the mechanisms implicated. Rats were sensitized to ovalbumin (OVA) following three hypersensitivity induction protocols, two parenteral and one oral. Rat mast cell protease II (RMCP II) release in response to OVA challenge and immunoglobulin E (IgE) concentration were measured in serum. At least 1 week after challenge, small intestinal motility was evaluated using strain gauges. Intestinal tissue samples from orally sensitized rats were checked for in vitro stimulation with OVA. Mucosal mast cells were counted from duodenum sections. All sensitized rats showed intestinal hypermotility. Only rats sensitized by parenteral procedure showed an increase in RMCP II after OVA challenge in serum. IgEs increased only in the Bordetella pertussis sensitized group. Small intestine sections from orally sensitized rats released more RMCP II than sections from control rats. All sensitized rats showed an increase in the number of mucosal mast cells in duodenum. In conclusion, hypersensitivity to food proteins induces chronic motor alteration that persists long after antigen challenge and an excited/activated state of sensitized mucosal mast cells.