Immediate hypersensitivity reactions to cow milk proteins in isolated epithelium from ileum of milk-drinking guinea-pigs: comparisons with colonic epithelia.

The epithelium lining the ileum has been isolated and studied in vitro under short-circuit conditions. Tissues were obtained from guinea-pigs fed cow milk. When challenged with beta-lactoglobulin on either the apical or basolateral side, a transient, inward flowing current was recorded. This reaction did not occur with tissues from non-milk drinking animals. Casein and alpha-lactalbumin, in contrast to beta-lactoglobulin, produced only minor effects while bovine serum albumin and bovine gamma-globulin were without effect. The effect with beta-lactoglobulin was associated with overall fluid secretion in the basolateral to apical direction, although the ions responsible for carrying the current have not been identified. Possible mediators of the response to beta-lactoglobulin have been investigated. Throughout the responses of the ileum have been compared with those in the colon. The differences between the two tissues is striking. The relevance of the model to mechanisms of food intolerance is discussed.