杀菌性/通透性增加蛋白模拟肽中和内毒素作用的研究

目的　观察 4种杀菌性 /通透性增加蛋白 (BPI)模拟肽 (10 342、10 343、10 344、10 345 )体内外中和内毒素 (LPS)的作用。　方法　采用定量鲎基质显色法测定BPI模拟肽体外中和LPS的能力 ;采用尾静脉给药方法 ,观察BPI模拟肽对LPS攻击小鼠的保护作用 ;测定BPI模拟肽对LPS血症模型大鼠TNFα及IL 6影响。　结果　BPI模拟肽具有中和LPS的能力 ,中和能力随浓度增加而增加 ,其中 10 342的作用最强 ;不同BPI模拟肽对LPS血症小鼠具有强大的保护作用 ,保护率达 90 % ,并可明显降低LPS血症模型大鼠各时相点血清TNFα及IL 6水平。　结论　杀菌性 /通透性增加蛋白 (BPI)模拟肽不仅具有体外中和LPS的能力 ,而且对LPS血症动物具有强大的保护作用。

The study on the role of modeling peptides derived from bactericidal/permeability increasing protein on the endotoxin neutralization

OBJECTIVE: To observe the role of four modeling peptides (10342, 10343, 10344, 10345) derived from bactericidal/permeability increasing protein (BPI) in neutralizing endotoxin (LPS) in vitro and in vivo. METHODS: Quantitative limulus amoebocyte lysate assay was employed to evaluate the capacity of BPI peptides in neutralizing endotoxin in vitro. The protective capacity of the peptides was observed in mice challenged with endotoxin by intravenous administration via the tail vein. The influence of the peptides on serum TNFalpha and IL-6 levels in rats with endotoxemia were also observed. RESULTS: All of the four peptides possessed endotoxin-neutralizing capacity which was strengthened along with the increase in their concentration. Among the peptides, 10342 is the strongest one. All of the peptides had strong power to protect mice from endotoxin with 90% protective rate. In the rats with endotoxemia, the four peptides could reduce the levels of serum TNFalpha and IL-6 significantly at different time-points. CONCLUSION: Four BPI modeling peptides possessed not only endotoxin-neutralizing capacity in vitro, but also potential protective capacity in animals challenged with endotoxin.