Relative allergenicity of cow's milk and cow's milk-based formulas in an animal model
Kitagawa, S.; Zhang, S.; Harari, Y.; Castro, G.A.
American Journal of the Medical Sciences 310(5): 183-187
1995
ISSN/ISBN: 0002-9629 PMID: 7485221 Document Number: 454187
In this study, the allergenicity of cow milk and milk-based formula was evaluated by examining intestinal anaphylaxis caused by challenge with a milk protein fraction, beta -lactoglobulin ( beta LG), in guinea pigs orally sensitized to these diets. Colonic segments were removed and challenged with beta LG. An antigen-induced, anaphylactically-mediated elevation of transmural short circuit current, which is caused by net chloride (Cl-) secretion, was measured in using chambers as an index of local immune responsiveness. After removal of the colon, all guinea pigs were challenged by intracardiac injection with beta LG to examine the onset of bronchospasm, a test for systemic anaphylaxis. Whereas colonic segments from all guinea pigs fed whole cow milk responded to challenge with beta LG, segments from only 60% of animals fed cow milk formula responded to the challenge. In addition, the responders in the latter group had a significantly lower magnitude of beta LG-induced Cl- secretion compared with animals sensitized to whole cow milk. In parallel, bronchospasm developed in all guinea pigs fed whole cow milk. In the group of animals fed cow milk formula, bronchospasm developed only in those who responded to the intestinal challenge. On the basis of these results, cow milk-based formula has less sensitizing power than whole cow milk in this animal model, and the approach is effective in testing allergenicity at the intestinal level.