[Determination of beta-endorphin plasma concentrations in surgical patients with acute abdominal pain]

Abdominal pain and surgery, frequently associated with this kind of pain, modify plasma levels of stress-hormones and iniciates the response of endogenous analgetic system. The aim of this study was to determine serum concentration of beta-endorphine in patients with acute abdominal pain (n=12), which were surgically treated. Serum concentration of beta-endorphin was measured on five data points: before, during and after surgery. During abdominal surgery serum concentration of beta-endorphin was increased by 7% compared to preoperative period; in postoperative period the concentration continued to rise and remained increased within next hours. The maximal levels of beta-endorphine were not observed during, and immediately after surgery. Postoperatively, between 6 and 8 p.m. on the day of surgery, maximal level of beta-endorphin was noted, which was even ten times higher than to preoperative value. Plasma level of beta-endorphin fell to the baseline values 24 hours after surgery. In conclusion, abdominal surgery induces a postponed (delayed) increase in serum beta-endorphine levels, which are associated with modulation of preoperative, intraoperative and postoperative pain perception.