Abstract
Recently, it has be reported that amino acid residues may be absorbed more rapidly from di- and tripeptide than from free amino acid during the protein digestion. The aim of the present study is to compare the absorption effect of enterally administered oligopeptides and amino acids. Two isonitrogenous chemically defined diets (CDD), one containing a partial enzymic hydrolysate of casein which approximately 67% of nitrogen content was present as oligopeptide (peptide CDD), and the other containing a mixtures of L-synthetic amino acid (amino acid CDD), were administered to Thiry Vella loops of weanling rats. The other composition like carbohydrate, fat, mineral, and vitamin, were just same. The comparison study was done by following parameters; residual fluid volume in the loop, residual nitrogen weight in the loop, plasma amino acid concentrations of portal vein. The residual nitrogen weight in the loop significantly decreased at 15min. (p<0.05), 30min. (p<0.01), 120min. (p<0.01) after the administration in the peptide CDD rats rather than in the amino acid CDD rats. The concentrations of free amino acid in plasma of portal vein were significantly greater at 15 min. (p<0.01) after the administration in the peptide CDD rats than in the amino acid CDD rats. Amino acids which were promptly absorbed in the administration of each CDD, were Thr. Phe. Ala. Ser. in the peptide CDD whereas Arg. Leu. Cys. in the amino acid CDD. These results suggested that there might be nutritional advantages especially in the younger, if peptides rather than L-synthetic amino acids were used as a nitrogen source in chemically defined diet.
