Dynamic change of reticuloendothelial system function after surgical stress

The influence of surgical stress on the function of the reticuloendothelial system (RES) is not well elucidated. Because we established an in vivo functional test for the RES by using chondroitin sulfate iron colloid in rabbits, the normal range of RES function in healthy volunteers (n = 12) and the dynamic change of RES function in surgical patients after distal gastrectomy (n = 14) were examined by this method. In healthy volunteers, the maximum phagocytic velocity and membrane-particle constant were 0.0310 +/- 0.0052 mg/kg per minute and 0.575 +/- 0.205 mg/kg, respectively. In surgical patients, maximum phagocytic velocity (postoperative day 1, 0.0408 +/- 0.0088; postoperative day 3, 0.0486 +/- 0.0115; and postoperative day 7, 0.0430 +/- 0.0115 mg/kg per minute) and membrane-particle constant (postoperative day 3, 0.717 +/- 0.169 mg/kg) significantly increased postoperatively in comparison with preoperative values. These results indicate that the total capacity of the RES is augmented but that its functional phagocytic efficiency is diminished after abdominal surgery. This phenomenon is considered to be one of the immunological alterations caused by surgical stress. The chondroitin sulfate iron colloid test can be applied to monitor the dynamic change of the RES function under various conditions.