A peroral test of pancreatic insufficiency with 4-(N-acetyl-L-tyrosyl)aminobenzoic acid in children with cystic fibrosis.

We report on the examination of stimulated pancreatic secretion using 4-(N-acetyl-L-tyrosyl)aminobenzoic acid 
in children with cystic fibrosis. In controls the urinary excretion of 
4-aminobenzoic acid amounted to 54.8 +/- 11.7% with 19.6% as the 
lower limit of normal during six hours, and 74.7 +/- 10.8% 
and 40.5% during eight hours. In children with cystic fibrosis the 
mean values were 5.6% in the six-hour test and 13.7% in 
the eight-hour test. Both values are significantly different in comparison with 
controls. It may be assumed that both 4-(N-acetyl-L-tyrosyl)aminobenzoic acid and 4-(N-benzoyl-L-tyrosyl)aminobenzoic 
acid are suitable for indirect determination of exocrine pancreatic secretion in 
children. 