The Intestinal Absorption of Amino Acids and Peptides with Special Reference to the Domestic Fowl: A Literature Review

Abstract

SummaryThe transport of amino acids via the chick small intestine has been shown to be an active process, obeying Michaelis-Menten type kinetics and having preference for L amino acids. Different transport systems can be discriminated for methionine and related aliphatic amino acids, proline and related amino acids, glycine and the basic amino acids. Maximum transport of the amino acids usually occurs in the second half of the small intestine. The amino acid transfer is sodium-dependent and is inhibited by sugars, although the exact nature of these interrelations is still a matter of debate. Metabolic inhibitors as well as vitamin deficiencies reduce amino acid transport. The age and pyhsical condition of the animal may have a marked effect on amino acid transfer. From the nutrition viewpoint the uptake of protein digestion products in the form of small peptides may be more important than the absorption of free amino acids.