A ne w test of exocrine pancreatic function using N-benzoyl-L-tyrosyl-p-aminobenzoic acid

Part I. Fundamental study and the diagnostic value of the test

Abstract

N-benzoyl-L-tyrosyl-p-aminobenzoic acid (BTPABA), a new synthetic peptide is specifically hydrolyzed by chymotrypsin to yield p-aminobenzoic acid (PABA), which is estimated colorimetrically by diazotizing.
The method suitable for assay of chymotrypsin in duodenal aspirates was investigated using BTPABA as a substrate. Then the chymotrypsin output during PS-test was estimated in the patients with pancreatic disorder. The chymotrypsin output significantly correlated to the trypsin output (P<0.001) and to the amylase output (P<0.001). A good correlation was also noted between the chymotrypsin output and the 6 hr-urinary excretion of PABA in PFD (P<0.01).
These obserbations demonstrate that pancreatic enzymes are secreted in parallel, and pancreatic disease is found to result in parallel decrease in the secretion of chymotrypsin, trypsin and amylase, and that PFD is an accurate diagnostic test of exocrine pancreatic function.