OBJECTIVETo study hepatic NF-κB level following endotoxemic liver injury, and its relationship with hepatic TNF-α and IL-6 levels in young rats.

METHODSForty 18-day-old rats were randomly assigned to a normal control and an endotoxemia group. Endotoxemia was induced by lipopolysaccharide injection (LPS, 5 mg/kg). The endotoxemia group was subdivided into four groups sampled at 2, 6, 12 and 24 hrs after LPS injection (n=8 each). Pathological changes in liver cells were observed under a light microscope. TNF-α and IL-6 levels in liver tissue homogenates were measured using ELISA. Reitman-Frankel was used to measure serum ALT concentrations. NF-κB activation level in liver tissues was detected by immunohistochemistry.

RESULTSLiver tissue injury was the most obvious 6 hrs after LPS injection under the light microscope, and the damage rating of liver tissues was significantly higher in the endotoxemia group than that in the normal control group at all time points (P<0.05). ALT levels in the endotoxemia group were significantly higher than those in the normal control group 6, 12 and 24 hrs after LPS injection (P<0.05). NF-κB p65 protein expression in liver cells (percentage of nuclear positive cells) in the endotoxemia groups was significantly higher than that in the normal control group (P<0.05). TNF-α and IL-6 levels in liver tissue homogenates in the endotoxemia groups were significantly higher than those in the normal control group 6 and 12 hrs after LPS injection (P<0.05).

CONCLUSIONSEndotoxemia can cause liver injury, resulting in liver cell damage and changes in liver function. NF-κB activation is involved in endotoxemic liver injury which may be mediated by inflammatory cytokines TNF-α and IL-6 synthesis.