Effects of vagotomy on serum endotoxin, cytokines, and corticosterone after intraperitoneal lipopolysaccharide

The vagus nerve appears to play a role in communicating cytokine signals to the central nervous system, but the exact extent of its involvement in cyt okine-to-brain communication remains controversial. Recently, subdiaphragma tic vagotomy was shown to increase bacterial translocation across the gut b arrier and thus may cause endotoxin tolerance. The current experiment teste d whether or not vagotomized animals have similar systemic responses to end otoxin challenge as do sham-operated animals. Subdiaphragmatically vagotomi zed and sham-operated animals were injected intraperitoneally with one of t hree doses (10, 50, 100 mu g/kg) of lipopolysaccharide (LPS) or vehicle, an d blood samples were taken at 15, 30, 60, 90, and 120 min after the injecti on. The intraperitoneal injection of LPS increased circulating LPS levels a t all time points examined. In addition, all three doses of LPS significant ly increased serum interleukin (IL)-1 beta, IL-6, and corticosterone in bot h control and vagotomized rats. In conclusion, vagotomy itself has no marke d effect on circulating endotoxin levels or the production of IL-1 beta, IL -6, or corticosterone in blood after an intraperitoneal injection of LPS.