[An experimental study on the role of beta-endorphin in the pathogenesis of acute pancreatitis and the effects and mechanisms of naloxone].

120 SD rats were randomly divided into three groups: the sham operation group, the AP (acute pancreatitis) group, the naloxon treated group. AP was induced by intraductal injection of 5% sodium taurocholate solution. Naloxon was given intramuscularly at the dosage of 0.1 g/100 gw immediately after the injection and 90 minutes later. The survival rate and the mean survival time of the rats during 3 days after the induction of AP were determined. The pancreata were sampled for semiquantitative histopathologic evaluation. By using the fractional indicator distribution technique with 86 RB, QP/CO and pancreatic tissue perfusion performed 1 and 6 hours after the induction of AP, the amount of beta-endorphin in the hypothalamus and pituitary was measured 1 and 4 hours after the induction of AP. It was found in the naloxon treated group, the pancreatic blood flow and tissue perfusion was greatly increased, the mortality rate was decreased, and the rats survival time was significantly prolonged. The results suggest that: (1) The hemodynamic changes play an important role in the pathogenesis of AP. (2) Beta-Endorphin may play a role in the pathophysiological process of AP. (3) naloxon has good therapeutic effects on AP.