H. Hagemeister et P. Antila, ORO-ILEAL DIGESTIBILITY OF HOMOARGININE-LABELED BETA-LACTOGLOBULIN AND CASEIN IN ADULT MINIATURE PIGS, Journal of animal physiology and animal nutrition, 72(2-3), 1994, pp. 86-91
beta-Lactoglobuiin (beta-Lg) binds retinol and may function as a physi
ological retinoid carrier-protein. Previous in vitro studies and one i
n vivo study suggest a structural and conformational stability of beta
-Lg in comparison to casein, reflected by a different digestive pace a
nd a reduced prececal digestibility. Eight adult male Gottingen miniat
ure pigs were fitted with a permanent T-cannula at the ileum and were
then fed meals containing homoarginine-labelled proteins. Absorption o
f beta-Lg and casein was estimated based on the disappearance of homoa
rginine. Absorption was 97.7 +/- 0.9% for beta-Lg and 97.9 +/- 0.3 % f
or casein. If there is a higher proteolytic resistance to beta-Lg then
to casein, this does not persist throughout the whole small intestine
. If beta-Lg can function as a physiological retinol carrier protein,
this would be limited to the stomach and the upper small intestine.