['The gut is a central organ in the postoperative stress reaction. We previously reported that measuring gut-mucosal cytokines may more accurately reflect the response to operative stress. Additionally, we have shown that the gut demonstrates a blunted cytokine response after laparoscopy as compared with laparotomy.', 'To further investigate whether this differential response is caused by exposure of the peritoneal cavity to general atmospheric air during laparotomy, 80 A/J mice were randomized equally into four groups: CD (carbon dioxide [CO2] pneumoperitoneum), RA (room air pneumoperitoneum), AP (anesthesia and port insertion only), and PC (pure control, no intervention). Pneumoperitoneum was established and maintained at 3 mmHg for 60 min. All the mice were killed 4 h after the intervention. Jejunal mucosa and serum samples were collected and analyzed for interleukin-6 (IL-6) levels. Results were analyzed by analysis of variance (ANOVA).', 'Gut-mucosal IL-6 in the RA group was significantly higher than in all other groups: RA, 1,354.5 +/- 117.9* vs. CD, 964.3 +/- 114.0 vs. AP, 960.2 +/- 86.2 vs. PC, 908.0 +/- 83.6; *p < 0.05. The CD group did not show a significant increase in gut-mucosal IL-6 as compared with the AP and PC groups. Similarly, RA resulted in significant increases in serum IL-6 as compared with AP and PC, whereas CD showed no significant difference: RA, 161.3 +/- 66.2* vs. 95.1 +/- 1 vs. AP, 10.6 +/- 5.3 vs. PC, undetectable; *p < 0.05. There was no difference in serum IL-6 level between CD or any of the other groups.'] Does laparoscopic insufflation with room air cause exaggerated interleukin-6 response?