Lipolytic enzymes may play a role in the pathogenesis of acute pancreatitis. Therefore, the effects of a lipase inhibitor, THL (tetrahydrolipstatin), a protease inhibitor, FUT (nafamostat mesilate), and albumin under different conditions in rats were investigated. (a) Isolated pancreatic acini were incubated with pancreatic homogenates and triglycerides or lecithin with or without albumin and the degree of cellular destruction quantitated. (b) Taurocholate was injected into the pancreatic duct of isolated pancreas and the organ continuously perfused with either FUT, THL, or albumin. Organ damage was evaluated by measurement of pancreatic enzymes in the portal effluence. (c) Necrotizing pancreatitis was induced in vivo via retrograde taurocholate injection. FUT, THL, or albumin was applied either intravenously or injected into the pancreatic parenchyma. (a) Albumin prevented the cellular damage caused by both fatty acids and lysolecithin. (b) THL was ineffective, FUT lowered the release of pancreatic enzymes into the portal effluence, and albumin was most effective. (c) Albumin prevented the development of panlobular necrosis and lowered the degree of extrapancreatic fat necrosis. Albumin, via its ability to bind detergents, may have therapeutic implications.