Utilization of Enzymatically Hydrolyzed Soybean Protein and Crystalline Amino Acid Diets by Rats with Exocrine Pancreatic Insufficiency

Abstract
Exocrine pancreatic-deficient rats (PD) were prepared by cannulation and ligation of the common duct in a way which permitted bile, but not pancreatic juice, to enter the intestine. After surgery the PD rats were fed purified diets containing a high quality nitrogen source in the form of crystalline amino acids (AA), an enzymatic hydrolysate of soybean protein supplemented with essential amino acids (EH) or intact soybean protein with an essential amino acid supplement (SP). PD rats fed SP failed to regain any of their surgically-induced weight loss during the 10-day postoperative period. PD rats fed AA did not resume weight gains until after the sixth postoperative day while those fed diet EH resumed growth by the third postoperative day and grew at a rate which was nearly identical to that observed in sham-operated controls. The three diets afforded almost identical growth rates in weanling rats and in sham-operated rats used as controls for the PD rats. The amino acid compositions of AA and EH were nearly identical. Thus, the better utilization of diet EH in the PD rats was attributed to the fact that approximately 85% of the nitrogen in EH was in the form of oligopeptides. The results indicate that pancreatic enzymes are not required for the terminal stages of protein digestion and suggest that enzymatically hydrolyzed proteins are utilized more efficiently than mixtures of amino acids in the absence of exocrine pancreatic function.