Absorption of amino acids in different parts of the small intestine in growing pigs. II. Effect of addition of certain amino acids on absorption of different amino acids from acid hydrolysed casein.

The study was carried out on pigs weighing 50 to 60 kg with temporarily isolated loops of the upper and the distal halves of the small intestine. Isolated segments 90 to 180 cm long were perfused at a rate of 720 ml/h with solutions of acid casein hydrolysate to which 100 to 300 per cent of the original contents of some amino acids was added. The changes of amino acid composition of the solution used for perfusion influenced to a large extent of the absorption of different amino acids. Leucine, methionine and arginine, the amino acids with the greatest affinity to the transport mechanism, were most active in inhibiting the absorption of the other amino acids from the small intestine.