Comparative study of the estimation of exocrine pancreatic function using p-(N-acetyl-L-tyrosyl)- and p-(N-benzoyl-L-tyrosyl)aminobenzoic acid.

A comparative study using the oral test with chymotrypsin substrates p-(N-acetyl-L-tyrosyl)- and p-(N-benzoyl-L-tyrosyl) aminobenzoic acid (Ac-Tyr-PAB and Bz-Tyr-PAB) was carried out in 43 adults divided into four groups comprising controls (n = 18), chronic pancreatitis (n = 13), after acute pancreatitis (n = 7), and celiac sprue (n = 4), after separate administration of both derivatives and determination of PABA urinary output in 6 and 8 hours. Both derivatives were diagnostically comparable. The specificity of both derivatives in the investigated group in 6 and 8 hours was 100%, and test sensitivity in patients with chronic pancreatitis, was in 6 hours 90.9% for Ac-Tyr-PAB and 72.7% for Bz-Tyr-PAB, and 8 hours 81.8% for both compounds. Differentiation between the controls and the chronic pancreatitis group was better in Ac-Tyr-PAB, as adjudged by the sensitivity and significance of the Student t-test criterion.