Effect of Coexistence of Di-, Tripeptides and Amino Acids on Absorption of Nitrogen Source

Abstract

A study was undertaken to clarify the effect of coexisting di-and tripeptides and amino acids on absorption of a nitrogen source. Absorption of amino acids from di-and tripeptides partially replaced with a free amino acid mixture was compared with that from a free amino acid mixture or di-and tripeptides or lactalbumin. Absorption was evaluated by calculating the area under the curve of amino acid concentration in portal vein plasma of rats for 120 min after administration of each nitrogen source. The absorption was maximal upon administration of the nitrogen source when di-and tripeptides and free amino acids were present. These results indicate that the transport mechanisms for amino acids and peptides in rats are independent and work simultaneously.