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N E Byars

Publications and source records attributed to N E Byars.

20 records · Page 2Linked to original sources

Inhibition of rat intestinal anaphylaxis by various anti-inflammatory agents.

Adverse reactions to food may, in some cases, be due to IgE-mediated immune reactions to the ingested antigens. A mast cell protector has been shown to protect patients against challenge with food to which they are sensitive. An IgE-mediated intestinal anaphylaxis reaction in the rat has been developed as a model of some aspects of human food allergy. Using this model, a number of xanthones and other anti-inflammatory agents were tested for activity in inhibiting intestinal anaphylaxis. The compounds were also tested for inhibitory activity against the IgE-mediated rat passive cutaneous anaphylaxis reactions. The xanthones protected against both reactions, as did isoproterenol and cyproheptadine, while aspirin, indomethacin, and dexamethasone inhibited the intestinal but not the cutaneous reaction. This suggests that while IgE-triggered mediator release from mast cells is important in both reactions, other mechanisms may also be operative in the intestinal reaction. Furthermore, the use of xanthones and other anti-inflammatory compounds may be a useful mode of therapy in human food allergy.

Anaphylaxis↗

Intestinal anaphylaxis in the rat as a model of food allergy.

An animal model of food allergy has been developed in which some aspects of the allergic response could be quantified and the effects of various drugs evaluated. The change in permeability of the intestinal tract of actively sensitized rats, after oral challenge with the sensitizing antigen, was the parameter measured. Rats were sensitized by injection of egg albumin and B. pertussis vaccine to induce reaginic antibody to egg albumin. Two weeks after sensitization, 125I-labelled bovine serum albumin (125I-labelled BSA) was injected intravenously, followed by oral challenge with egg albumin. Pieces of intestinal tissue were obtained and the amount of 125I-labelled BSA determined in a gamma counter. The amount of 125I-labelled BSA in the intestinal tissue of sensitized and challenged rats regularly showed an increase of greater than 100% above values for control rats.

Anaphylaxis↗