Absorption kinetics of amino acids and reducing sugars during digestion of barley or wheat meals in the pig : Preliminary data

Abstract

Summary. The digestion of barley and wheat was studied in the pig using a metho- dology quantitatively describing the apparent absorption kinetics of amino acids and reducing sugars. This methodology is based on the simultaneous and continuous measure- ment of the postprandial increase of the level of these nutrients in the efferent blood of the digestive tract (porto-arterial differences) and the measurement of the portal vein blood flow. After an 18-hr fast, the experimental meals (18 for barley, 22 for wheat) were given to animals weighing 40 to 50 kg in amounts varying from 200 to 1 600 g ; recordings were taken over a periprandial period of 10 to 12 hrs. The following main results were obtained : essential amino acids, aromatic amino acids and methionine appeared more rapidly. On the other hand, arginine and cystine appeared more they were metabolized in the digestive wall. Among the non-essential amino acids, glutamine and glutamic acid appeared very slowly and alanine and glycocolle very quickly and intensely ; non-alimentary products such as citrulline and ornithine were synthesized. Absorption balance after 8 hrs of digestion, as shown by absorption percentages, ranged from 71 p.100 (histidine) to 20 p. 100 (cystine) for barley and between 90 and 29 p. (same amino acids) case of both and glycine in the case of were synthe- sized. The absorption coefficient of glutamic and glutamine very cases.