Carbon dioxide pneumoperitoneum reduces levels of TNF-alpha mRNA in the brain, liver, and peritoneum in mice

Background: Cytokines are important regulators of the biological response t o surgical stress. The aim of this study was to determine whether the CO2 p neumoperitoneum would change the expression of TNF- alpha mRNA in the visce ral organs, including the brain, in mice. Methods: Mice were randomly assigned to one of six groups: control, anesthe sia alone, insufflation with carbon dioxide, insufflation with air, laparot omy by short incision, or laparotomy by long incision. The brain, liver, je junum, and peritoneum were harvested either 3 or 24 h after surgery. Levels of TNF-cr mRNA in each tissue was measured by semiquantitative reverse tra nscription-polymerase chain reaction (RT-PCR). Results. The air insufflation group showed higher TNF-alpha mRNA levels in the brain and liver than the short-incision group. Levels of TNF-alpha mRNA in the brain, liver, and peritoneum were lower in the CO2 pneumoperitoneum group than in the air insufflation group. Plasma IL-6 and catecholamine in the urine were lower in the CO2 pneumoperitoneum group than the air insuff lation group. Conclusion: Reduced synthesis of TNF-alpha in the visceral organs, includin g the brain, is correlated with a less marked biologic response to laparosc opic surgery.