WHAT IS PANCREATIC SECRETORY TRYPSIN INHIBITOR (PSTI) TEST?
PSTI is a potent protease inhibitor found in the pancreas, in the mucus-secreting cells of the gastrointestinal tract, and in the breasts, lungs, and kidneys. It is believed to be involved in healing after injury because it inhibits the proteolytic breakdown of mucus. It may also be capable of promoting growth activity. Newer studies suggest than PSTI gene alteration may be associated with the risk of developing chronic pancreatitis. PSTI is absorbed into the bloodstream and therefore can be measured by immunoradioassay. Absorbed PSTI is excreted in the urine. This test is performed by radioimmunoassay.