Effects of ketamine and propofol on the ratio of interleukin-6 to interleukin-10 during endotoxemia in rats.

Our previous study reported that the change in the ratio of interleukin (IL)-6 to IL-10 influences the severity of sepsis in patients with systemic inflammatory response syndrome. We evaluated the change in the ratio of IL-6 to IL-10 after administration of ketamine or propofol in endotoxin-exposed rats in order to evaluate the relationship of pro-inflammatory and anti-inflammatory cytokines following ketamine or propofol administration during endotoxemia. We randomly assigned 40 rats to one of four equal groups: endotoxin alone, receiving Escherichia coli endotoxin (15 mg/kg, i.v.); saline control; ketamine (10 mg x kg(-1) x h(-1), i.v.) before and during exposure to endotoxin; and propofol (10 mg x kg(-1) x h(-1), i.v.) before and during exposure to endotoxin. We measured the plasma concentrations of tumor necrosis factor (TNF)-alpha, IL-6, and IL-10 and calculated the ratio of IL-6 to IL-10 in each group. The current study showed that ketamine and propofol administration attenuated the increase in TNF-alpha, IL-6, and IL-10, and ketamine attenuated the increase in the ratio of IL-6 to IL-10, but propofol increased this ratio in rats receiving a single intravenous bolus of endotoxin. While the mechanisms responsible for the inhibitory effects require further investigation, our results suggest that proper use of ketamine as an anesthetic agent may offer certain advantages in the management of patients with endotoxemia.