Does antecedent ethanol intake affect course of taurocholate pancreatitis in rats?

The pathogenic role of acute ethanol abuse in acute pancreatitis (AP) is still obscure. The aim of the study was to evaluate the effect of antecedent intake of a high dose of 40% ethanol (5 g/kg body wt.), on trypsinogen activation, pancreatic lysosomal membrane labilization, and activities of phospholipase A2 and lipase in taurocholate AP in rats. In 80 male Wistar rats, AP or sham operation (SO) was produced 6 hr after intragastric saline (S) or ethanol (E) administration, and animals were sacrificed after 6, 12, and 18 hr. Free active trypsin (FAT) and total potential trypsin (TPT) were assayed in the pancreatic homogenate. Percentage free activity (%F/T) of cathepsin B was determined as an index of lysosomal membrane fragility. The most evident activation of trypsin occured at 6 hr AP (11.6% of TPT in S group and 16.4% in E group). Antecedent ethanol increased FAT 18 hr after SO from 0.105 +/- 0.048 microg/g protein to 0.258 +/- 0.054 and AP lasting 18 hr from 0.331 +/- 0.072 to 0.695 +/- 0.110. The %F/T of cathepsin B was highest at 18 hr of AP, suggesting maximal labilization of lysosomal membranes at this time. This labilization occurred earlier (at 12 hr of AP) in E group. The increasing effect of antecedent E on lipolytic enzymes was evident after 6 hr of AP. In conclusion, the antecedent intake of high dose of ethanol significantly promoted the conversion of trypsinogen to trypsin in taurocholate acute pancreatitis, whereas its additional effect toward labilization of pancreatic lysosomal membranes and the increase of lipolytic enzymes activities was less evident. Therefore, the promoting impact of acute ethanol intake in the development of acute pancreatitis could be mainly dependent on its increasing effect on trypsinogen activation.