A comparative study of a pancreatic function test utilizing a synthetic peptide(PFT) and the pancreozymin secretin test (PS test) was performed to evaluate the validity and limitations of PFT. PFT was found to be less sensitive than the PS test in detecting exocrine pancreatic dysfunction. PFT values were always abnormal when the exocrine pancreatic dysfunction was moderate to severe; i.e., the amylase output 40,000 units, maximal bicarbonate concentration 70 mEg/l and secretory volume 55 ml. When the pancreatic dysfunction was of a milder degree, PFT values were abnormal only half of the time. Consequently, a normal PFT value does not necessarily rule out pancreatic disease. PFT can give a false positive result in cases of cirrhosis of the liver, irritable bowel syndrome and renal insufficiency. When renal insufficiency is ruled out, a PFT value of less than 65 percent is diagnostic of pancreatic dysfunction. A PFT value of 65-70 percent can be obtained in diseases of other organs such as cirrhosis of the liver and irritable bowel syndrome. PFT is not as sensitive as the PS test, but it is a simple and useful exocrine pancreatic function test. It is an especially good screening test for
pancreatic diseases.