Surgical trauma induces group II phospholipase A2 production by neutrophils at a local site after surgery

Objectives: Group II phospholipase A2 (PLA2) regulates eicosanoids and platelet activating factor (PAF) production and plays an important role in regulating critical mediators in inflammatory diseases such as trauma, sepsis and multiple organ failure. To elucidate the local effect of surgical trauma, we investigated the production of group II PLA2 at a local site after surgery. Design and methods: We utilized a radioimmunoassay to measure group II PLA2 levels in peritoneal exudates from the operative field and blood in patients who underwent gastrectomy. We also investigated the production of group II PLA2 in cells from peritoneal exudates by Northern blotting and immunocytochemistry. Results: immunoreactive group II PLA2 levels were significantly increased from 3 h after surgery and peaked at 12 h in peritoneal exudates. However, serum group II PLA2 levels peaked at 24-48 h and decreased gradually after surgery, findings similar to levels of postoperative serum C-reactive protein (CRP). There was no significant correlation between group II PLA2 levels in peritoneal exudates and those in blood. Group II FLAP mRNA was expressed at high level in cells from peritoneal exudates, by Northern blot analysis, but not those from blood. The localization of group II PLA2 protein was intense in neutrophils, as determined by immunocytochemistry. No group II PLA2 expression was observed in corresponding peripheral blood cells. Conclusions: After surgery, group II PLA2 is increased in peritoneal exudates prior to elevation in the blood circulation and is produced by neutrophils recruited and activated at a local site. Group II PLA2 produced in peritoneal exudates by neutrophils has an important role in the physiological and pathological states at a local site, after surgery. Copyright (C) 1998 The Canadian Society of Clinical Chemists.