The in vitro transfer of bovine immune lactoglobulin across the intestine of new-born pigs.

1. Everted sacs of pig intestine, used soon after birth, maintained transmural potentials and transferred water and glucose to the serosal surface.2. Immune globulin, fed as bovine colostrum to the new-born pig, appeared in the serosal fluid of everted sacs during incubation in bicarbonate saline. The particular segment showing maximum transferring ability varied between limits and appeared to depend on the amount or concentration of colostrum fed to the pig. Sacs from unfed pigs incubated in bovine colostrum also transferred colostral IgG to the serosal fluid. This transfer was dependent on the concentration of colostral IgG in the incubation medium and became more pronounced in the middle third of the small intestine.3. Human serum albumin inhibited the transfer of colostral IgG and about twenty molecules of albumin were transferred for every molecule of colostral IgG, when both were presented together in equal concentration on the basis of weight, to the middle segment of the small intestine.4. Some of the immune globulin collected in vitro after feeding bovine colostrum was found in a degraded form, but the amounts present could not be estimated. There was no apparent degradation of immune globulin in the purely in vitro experiments.5. The in vitro transfer of bovine colostral IgG showed selectivity between molecules of albumin and colostral IgG, the nature of which warrants further study.