高密度脂蛋白的抗内毒素作用

Role of High Density Lipoprotein in Protecting Against Endotoxin Toxicity

目的 研究高密度脂蛋白 (HDL)抗内毒素 (LPS)的作用。方法 (1)用超离心方法分离纯化血浆各脂蛋白 ;(2 )分别给小鼠注射LPS ,HDL +LPS ,HDL +无脂蛋白血浆部分 (LFF ,d >1.2 1g/cm3 ) +LPS后观察各组小鼠的存活时间 ;(3)FITC LPS与人血浆培育后密度梯度离心观察荧光素在人血浆中的分布 ;(4 )FITC LPS、HDL及LFF培育不同时间 (0～ 3h)后密度梯度离心 ,观察不同培育时间HDL中的荧光强度 (FS)。结果 注射HDL +LFF +LPS组小鼠的存活时间 (4 0 .98± 12 .39)h比注射LPS组 (18.4 5± 2 .0 9)h和HDL +LPS组(2 2 .4 8± 12 .81)h小鼠显著性增长 (P <0 .0 1) ,而注射HDL +LPS组小鼠的存活时间与注射LPS组小鼠无显著性差异。FITC LPS在血浆VLDL、LDL层中的含量极低 (2 .77% ) ,主要集中在HDL层中 (6 0 .39% )。FITC LPS在HDL中的含量随培育时间增加而增加 ;而FITC LPS在LFF中的含量随培育时间增加而减少。结论 HDL具有抗内毒素的作用 ,并且HDL是血浆中与内毒素结合的主要组分。LFF参与HDL与LPS的结合过程。

Purpose: To study the function of HDL to proctect against bacterial endotoxin toxicity. Methods: (1) Plasma lipoproteins were isolated and purified by ultracentrifugation. (2) After injecting LPS, HDL + LPS, HDL + lipoprotein-free plasma fraction (LFF, d > 1.21 g/cm3) + LPS respectively, we investigated mouse survival time in each group. (3) After incubation of FITC-LPS with human plasma and ultracentrifugation, the distribution of fluorenscence strength(FS) in plasma was investigated. (4) After incubation of FITC-LPS with HDL and LFF for different time (0-3 h) and ultracentrifugation, FS in HDL and LFF was measured respectively. Results: The mouse survival time in group of HDL + LFF + LPS (40.98 ± 12.39) hr was longer significently than LPS group (18.45 ± 2.09) hr and HDL + LPS group (22.48 ± 12.81) hr (P 0.05). The FS in VLDL and LDL was very low (2.77%) and FS was mainly concentrated in HDL (60.39%). With the incubation time increased, the FS in HDL was increased and FS in LFF was decreased. Conclusions: HDL has the ability of protecting against LPS, and is a main component in plasma to combine LPS. LFF participates the binding process between HDL and LPS.