Antigenic stimulation with proteins of cow's milk via the oral route in guinea pigs and rats. 1. Measurement of antigenically intact beta-lactoglobulin and casein in the gastrointestinal contents of duodenum, jejunum and ileum.

Guinea pigs and rats drinking cow's milk ad libitum have had the contents of their stomach, duodenum, jejunum and ileum examined for antigenically native, undigested beta-lactoglobulin and casein. The whey protein was present, in every case, in higher concentration and could be found, although in decreasing amounts, right down to the ileum. In the rat, casein could not be shown at any level of the small intestine and in the guinea pig only at the level of the duodenum.