Effects of C1-esterase inhibitor in three models of acute pancreatitis

The present studies were done to evaluate the therapeutic potential of C1-esterase inhibitor in three different models of acute pancreatitis: (1) Edematous pancreatitis with acinar cell necrosis was induced by 7-h ip injections of 50 micrograms/kg cerulein in mice; (2) Hemorrhagic pancreatitis was induced by feeding a choline-deficient, ethionine-supplemented (CDE) diet in mice; and (3) Hemorrhagic pancreatitis was induced by retrograde infusion of 0.6 mL 5% sodium-taurocholate into the pancreatic duct in rats. C1-esterase inhibitor was given at 100 mg/kg iv before the onset of pancreatitis and at certain intervals thereafter. The severity of pancreatitis was assessed at various times after its onset by determination of serum amylase, by grading of histological alterations, and by determination of survival (survival determined only in models of hemorrhagic pancreatitis). In some of the models, C1-esterase inhibitor slightly ameliorated the degree of histological alterations; the increase in serum amylase was reduced by C1-esterase inhibitor only in CDE diet-induced pancreatitis. In all three models, C1-esterase inhibitor, however, failed to cause major beneficial effects and also failed to improve survival in taurocholate- and diet-induced pancreatitis. Additional studies in 12 patients with acute pancreatitis showed that C1-esterase inhibitor activity was markedly increased in serum of all patients during the first 9 d of the disease, suggesting that C1-esterase inhibitor behaves like an acute phase protein. Taken together the results from the animal and the human studies, C1-esterase inhibitor appears to only have a limited potential for treatment of acute pancreatitis.