One of the basic purposes of this study is to synthesize and characterize low molecular weight inhibitors of trypsin and of related proteases and to determine the effects of these inhibitors in vitro as well as in vivo. It is our goal to obtain highly potent, easily soluble, non-toxic compounds that will be useful in the treatment of hyperproteolytic conditions, such as tryptic pancreatitis, kallikrein-dependent shock, inflammatory states and complement-induced reactions. A second major project is the investigation of the mechanism by which protease inhibitors stimulate pancreatic enzyme formation and enzyme secretion. A special effort is directed towards elucidation of the interrelationship between biliary flow and exocrine pancreatic secretory activity.