OBJECTIVETo investigate the protective effect of recombinant human N-terminal lipopolysaccharide binding protein in mice challenged with LPS.

METHODSSeventy male Kunming mice were randomly divided into 3 groups, i.e. LPS challenge (Injection of LPS into abdominal cavity, n = 21); tLBP protection (Injection of LPS and tLBP into abdominal cavity, n = 21) and control (Injection of normal saline into abdominal cavity, n = 8) groups. The blood samples and tissue samples of the liver and lungs were harvested on 15 and 30 minutes and 1, 3, 6, 12 and 24 hours after the injection. The serum contents of ALT and TNF-alpha were determined by biochemical velocity analysis and RIA method, respectively. The pathomorphological changes in the liver and pulmonary tissue were examined under light microscope (LM). The mortality rate of ten mice each was observed within 24 hours after the injection of tLBP + 400 ng LPS or 400ng LPS.

RESULTSThe ALT content of tLBP group reached the peak level at 12 post-injection hour (PIH) (41.00 +/- 4.58), but it was significantly lower than that in LPS group in which it peaked at 6PIH (99.50 +/- 62.63) (P < 0.01). The TNF-alpha content in tLBP and LPS group was lower than that in LPS group, and both reached the peak level at 3 PIH (35.96 +/- 7.33). Compared with those in LPS, injury to hepatocytes in tLBP group was obviously milder without scattered necrosis. The pulmonary congestion in tLBP group was abated, and the inflammatory exudation in the alveoli was evidently less than that in LPS group. There were 9 out of 10 mice died in the LPS challenge group, while only 3 out of 10 mice died during 24 hours after LPS injection in tLBP protection group.

CONCLUSIONPreliminary results indicated that recombinant human tLBP might possess biological activity with a potential protection effect in LPS challenged mice.