EVALUATION OF NEUTROPHIL FUNCTIONS AFTER EXPERIMENTAL ABDOMINAL SURGICAL TRAUMA

Objective: In order to determine the effect of surgical trauma on neut rophil functions, we set up an experimental abdominal surgical model u sing rats and analyzed neutrophil functions. In addition, we measured tumor necrosis factor-alpha (TNF-alpha), cytokine-induced neutrophil c hemoattractant/growth-regulated oncogene (CINC/GRO) and nitric oxide ( NO) production. Materials and Methods: Male Sprague-Dawley rats, 8 wee ks old and weighing 250-270 g, underwent laparotomy (4 rats for each e xperiment). After the operation, neutrophil chemotaxis was assayed usi ng a modified Boyden chamber, and phagocytosis, active oxygen producti on and adhesion molecule expression were analyzed by flow cytometry. T NF-alpha and CINC/GRO levels were quantified by an immuno-dot-blot ass ay, and NO levels were measured by the Griess method. At the operation , NO inhibitor, N-G-monomethyl-L-arginine acetate (L-NMMA, 40 mg) was intraperitoneally administered, and the effect of L-NMMA was studied. Results: After the surgical trauma (24-48 h), blood neutrophil counts significantly increased (p < 0.001), and neutrophil chemotaxis, phagoc ytosis and active oxygen production were markedly enhanced (p < 0.01). Moreover, up-regulation of Mac-1 and down-regulation of L-selectin on neutrophils were observed (p < 0.05). The levels of TNF-alpha, CINC/G RO and NO increased remarkably in both blood and ascites at 8-48 h aft er the surgical trauma (p < 0.01): TNF-alpha increased from 194 +/- 9 (the mean +/- SD, n = 4) and 183 +/- 12 pg/ml (preoperation) to 797 +/ - 28 and 1045 +/- 137 pg/ml at 24 h in blood and ascites, respectively ; CINC/GRO increased from 0.1 +/- 0 and 0.1 +/- 0 ng/ml (pre-operation ) to 66.4 +/- 4.5 and 60.3 +/- 17.9 ng/ml at 8 h in blood and ascites, respectively; NO increased from 2.4 +/- 1.0 and 4.2 +/- 1.1 mu M (pre -operation) to 11.9 +/- 0.7 and 36.9 +/- 2.1 mu M in blood and ascites at 24 h and 48 h in blood and ascites, respectively. Interestingly, L -NMMA treatment significantly reduced the increased levels of TNF-alph a and CINC/GRO and altered the enhanced neutrophil functions (p < 0.05 ). Conclusion: These observations indicate that abdominal surgical tra uma induces the production of NO, TNF-alpha and CINC/GRO, and enhances neutrophil functions such as chemotaxis, phagocytosis and active oxyg en production. Furthermore, L-NMMA likely modulates the neutrophil fun ctions and the production of TNF-alpha and CINC/GRO after the surgical trauma.