Pancreatic secretory trypsin inhibitor as an acute phase reactant.

Pancreatic secretory trypsin inhibitor (PSTI) in serum is an acute phase reactant and increases remarkably in response to surgical stress or invasion. The magnitude of the elevation of serum PSTI is far greater than that of acute phase reactants previously known. Recent investigations revealed that human PSTI stimulated DNA synthesis in human fibroblasts and that PSTI bound specifically to various cultured cells. These findings together with the result that PSTI or a polypeptide very similar to PSTI stimulated the growth of endothelial cells suggested that PSTI could possess previously unknown physiological function as a growth-stimulating hormone.