Objective:To explore the mechanism of action of thymosin β 4 (Tβ 4) in septic shock by observing the 72h survival rate of septic shock mice treated with thymosin β 4 and exploring the changes of TNF-α and IL-1α.Methods:LPS(lipopolysaccharide) was intraperitoneally injected into clean Kunming mice to establish the animal model.①The Tβ 4

between normal and septic shock mice were determined.②The survival rate of septic shock mice was studied by intraperitoneal injection of Tβ 4.Animals were divided into four groups of 30 and each received LPS(25mg/kg)intraperitoneal injection.Group Ⅰ was LPS control group.GroupⅡ

Ⅲ and Ⅳ were individually injected with Tβ 4 at 0h

0h

2h;0h

2h

4h post LPS through caudal vein.③TNF-α and IL-1α were examined in septic shock mice by ELISA.Results:Tβ 4 was obviously decreased in the blood of septic shock mice.Tβ 4 could raise the 72h survival rate of septic shock mice and down-regulate inflammatory mediators.Conclusion:The optimal protective methods in the mouse appears to be 5mg/kg Tβ 4 given immediately following(0h) and at 2h and 4h successively post LPS.Tβ 4 down-regulates the inflammatory mediators

which may be the mechanism of Tβ 4 in curing the septic shock.