Effects of ketamine on lipopolysaccharide-induced depression-like symptoms in rats

Objective To investigate the effects of ketamine on lipopolysaccharide-induced depression-like symptoms in rats.Methods Thirty male Wistar rats were equally randomized into 3 groups of C(control group),S(saline group) and K(ketamine group).Lipopolysaccharide 1 mg/kg was intraperitoneally injected in the rats of groups of K and S,which were given ketamine 10 mg/kg or same volumn of saline 24 hours later,respectively.Thirty minutes later,forced swimming test(FST) was carried out in 3 groups and the immobility time during FST was recorded.Subsequently,all rats were sacrificed and prefrontal cortex was harvested for the determinations of IL-1β and IL-6 by ELISA.Results Compared with group C,the immobility time of FST was longer(P0.01) and expressions of IL-1β and IL-6 in prefrontal cortex were higher(P0.05) in group S.Compared with group S,the immobility time of FST was shorter and expressions of IL-1β and IL-6 in prefrontal cortex were lower in group K(P0.05).Conclusion Ketamine is able to ameliorate lipopolysaccharide-induced depression-like symptoms in rats,which is probably related to downregulation of IL-1β and IL-6 in the prefrontal cortex.