Intestinal Permeability to Proteins in the Newborn Herbivore

Abstract

The permeability of the gut of the newborn herbivore to the protein molecules of milk whey is largely lost within 24 hours following birth. All of the colostrum whey proteins, not only the antibody fraction, are absorbed during this stage of intestinal permeability. The nonantibody proteins are molecules of relatively low molecular weight. These are rapidly lost through the kidney, the antibodies being largely retained. Crystalline ß-lactoglobulin may be prepared from urine during the proteinuric stage which is very pronounced during the first 24 hours of postpartum life in calves that have had ready access to milk. Unsuccessful attempts were made to maintain the intestinal permeability beyond the first 24 hours of postpartum life. Hormonal and milk factors did not appear to be responsible for the discussed change. Transfusing with the blood of the mother and other biological agents were also ineffective.

Peroral administration of triiodothyronine (T3) affects absorption of immunolactoglobulins in calves

“…Steroid and thyroid hormones are implicated in the maturation process of the fetus and the newborn, and so their possible role as factors influencing lg absorption has long been studied. Deutsch and Smith (1957) unsuccessfully attempted to maintain the permeability of calf gut beyond 24 h postpartum, using diethylstilbestrol, progesterone, cortisol and ACTH given parenterally. In other studies, the concentration of cortisol at birth appeared to have no effect, but injections of ACTH have tended to increase serum Ig at 48 h (Stott and Rein-hard, 1978; Johnston and Oxender, 1979).…”

Protein Binding by Specific Receptors on Human Placenta, Murine Placenta, and Suckling Murine Intestine in Relation to Protein Transport across These Tissues

“…This transference may occur either prenatally via the placenta as in primates (1)(2)(3), both prenatally via the placenta and postnatally during the neonatal period via the intestinal tract (4,5) as in the rat and mouse, or primarily postnatally as in the pig and cow (6,7). Although other maternal plasma proteins such as serum albumin and transferrin also traverse the primate and murine placentas and the proximal intestine of the murine suckling, these proteins do so much less readily than does IgG.…”

The influence of specific chemical factors in the solvent on the absorption of macromolecular substances from the small intestine of the new‐born calf

“…During this period absorption is not limited to the immune globulins of colostrum, since a number of other macromolecular substances will pass across the wall of the small intestine (Deutsch & Smith, 1957; Balfour & Comline, 1959;Pierce, 1961;Pierce, Risdall & Shaw, 1964;Hardy, 1968).…”