[Permeability of the gastrointestinal tract to macromolecules in experimental anaphylaxis]

Rats were sensitized with single or multiple intraperitoneal administration of chick's egg ovalbumin (OA) or DNP-conjugated bovine serum albumin (DNP-BSA) on aluminium. The animals were challenged 14-28 days thereafter by intragastric or intravenous administration of respective antigens. Gastrointestinal barrier permeability was tested with macromolecular probes: OA and polyethylene glycol (PEG)-4000. The increase of permeability was revealed in animals sensitized with DNP-BSA and challenged intragastrically. The morphological view of intestinal damage included epithelial edema, exfoliation on the upper third part of the villi and also increases in the count of transepithelial lymphocytes. In OA-sensitized rats, the gastrointestinal permeability to PEG-4000 grew only following multiple sensitization and intravenous (or multiple intragastric) challenge with this antigen.