Effect of sodium thiopentone anesthesia on the phagocytic activity of rat peritoneal macrophages

To elucidate the effect of sodium thiopentone anesthesia on the function of phagocytic cells, albino rats were anesthetized with 60 mg/kg. of sodium thiopentone. After 90 min., peritoneal macrophages were harvested and their capacity for superoxide anion generation was detected. Following anesthesia for 90 min. latex particles were injected intraperitoneally, and after additional 30 min. the macrophages were derived, embedded in agar and the number of cells engaged in phagocytosis, as well as the number of latex particles engulfed by each individual cell were counted in semi-thick sections. Macrophages of anesthetized animals showed a statistically significant decrease of both superoxide anion generation and mean number of phagocytic cells, and engulfed fewer particles than those of the controls. Similar results were obtained following incubation of the cells with sodium thiopentone in vitro. The serum corticosterone level in anesthetized rats was significantly higher than that of the control animals. The results indicate that impaired phagocytosis following anesthesia induced by sodium thiopentone, in addition to alterations of the immune system caused by surgical trauma, may be one of the reasons for increased susceptibility to infections of surgical patients during the postoperative period.