Effect of intestinal anaphylaxis on gut function in the rat

Area of Science:

• Gastroenterology
• Immunology
• Allergy Research

Background:

• Food protein allergy can cause intestinal dysfunction.
• Anaphylaxis is a severe allergic reaction mediated by immunoglobulin E (IgE).
• Intestinal mucosal mast cells play a role in allergic responses.

Purpose of the Study:

• To investigate the impact of intraluminal antigen challenge on intestinal function in a rat model of anaphylaxis.
• To determine the role of histamine and mast cell mediators in antigen-induced intestinal dysfunction.

Main Methods:

• Hooded-Lister rats were sensitized to ovalbumin to induce anaphylaxis.
• Passive cutaneous anaphylaxis assay was used to measure anti-ovalbumin immunoglobulin E titers.
• Net water and electrolyte fluxes were measured in sensitized and control rats.
• Mucosal histamine levels and mast cell counts were analyzed post-challenge.

Main Results:

• Sensitized rats with high anti-ovalbumin titers showed significantly reduced absorption of water, Na+, Cl-, and K+ upon antigen challenge.
• Antigen challenge did not affect controls; the response was antigen-specific and irreversible.
• Antigen-challenged sensitized rats had lower mucosal histamine levels and reduced granulated mast cells.
• Histological examination revealed mucosal edema in sensitized animals.

Conclusions:

• Intestinal anaphylaxis leads to significant abnormalities in water and electrolyte absorption.
• Histamine and/or other mast cell mediators are likely responsible for these absorptive defects.
• This study provides insights into the mechanisms of food protein-induced intestinal dysfunction during anaphylaxis.