Evaluation of postoperative exocrine pancreatic function using chymotrypsin labile peptide.

The assessment of exocrine pancreatic function by the oral administration of a chymotrypsin labile peptide N-benzoyl-L-tyrosyl-p-aminobenzoic acid (BT-PABA) has proved to be an easy and reliable test of exocrine pancreatic function. It has the additional advantage that it can be used to study exocrine pancreatic function in all operative cases, even after gastrointestinal reconstruction. The recovery of p-aminobenzoic acid (PABA) correlates significantly with parameters of the PZ/CCK secretin (PS) test. Following Billroth II gastrectomy, the recovery of PABA decreased to 39.8 +/- 3.2% two weeks after and to 45.4 +/- 4.5% one to two months after operation, significantly lower than the 80.6 +/- 3.4% in normal subjects. In cases of cancer of the head of the pancreas, the exocrine function was 44.0 +/- 3.7%, and decreased to 17.5 +/- 3.0% after total pancreatectomy. Thus, BT-PABA enables a pertinent evaluation of pancreatic function in postoperative patients with various types of gastrointestinal reconstruction and also in cases when the PS test cannot be feasibly used.