Exocrine pancreatic function in protein-deficient patas monkeys studied by means of a test meal and an indirect pancreatic function test.

Exocrine pancreatic secretion was studied in 9 patas monkeys before and during protein depletion, and in 4 of them also during recovery from protein depletion. Pancreatic function was estimated by measuring enzymatic activities in the duodenal contents after a test meal and by determination of urinary excretion of p-aminobenzoic acid (pancreatic function test) after oral ingestion of the chymotrypsin-labile peptide N-benzoyl-L-tyrosyl-p-aminobenzoic acid. The average serum albumin dropped by 34.8% to 2.6 g per 100 ml. Significant decrease of trypsin, lipase, amylase, and chymotrypsin was observed in the duodenal samples during protein deficiency. Urinary excretion of p-aminobenzoic acid was also reduced significantly. The two tests correlated well. In 3 of 4 animals, recovery of pancreatic function was noted after refeeding a full protein diet. Pancreatic atrophy was noted in 2 animals which died. The study shows that exocrine pancreatic secretion can be seriously impaired even at a moderate protein deficiency and may not be reversibly in all instances. Therefore, function tests have to be evaluated with caution when hypoproteinemia, i.e., hypoalbuminemia, is present.