Uptake and modification of 125I-lipopolysaccharide by isolated rat Kupffer cells.
Uptake and modification of 125I-lipopolysaccharide by isolated rat Kupffer cells.
复制标题
分离的大鼠 Kupffer 细胞对 125I-脂多糖的摄取和修饰。
DOI：
10.1002/hep.1840080613
复制
发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Broitman,SA
中科院分区：
文献类型：
--
作者：
Fox,ES;Thomas,P;Broitman,SA
虽然一般认为肝清除脂多糖涉及枯否细胞，但所涉及的机制尚未完全阐明。本研究通过125 I标记的明尼苏达沙门氏菌脂多糖的体外组摄取和摄取后修饰实验来评估这一现象。在各种条件下，将125 I脂多糖加入悬浮培养的库普弗细胞中。在体外组摄取的125 I脂多糖浓度高达33.33 μg/ml时不饱和。在16.67 μg/ml下进行的动力学实验表明，Kupffer细胞在孵育60 min后不饱和。然而，在存在10倍过量未标记脂多糖的情况下孵育可抑制摄取动力学，表明摄取过程的一个组分可能受到限制。通过在1 mM 2-脱氧葡萄糖存在下孵育，证实了该过程中的能量依赖性，其抑制了约30%的125 I-脂多糖摄取。用7.5 × 10− 5 M秋水仙素预处理对动力学没有影响，这意味着细胞骨架在脂多糖摄取中没有作用。这些结果与先前提出的受体介导的过程不一致。修饰的内化标记已被证明的变化，浮力密度在氯化铯等体积密度梯度与枯否细胞过夜孵育后。这些结果表明，枯否细胞在体外清除细菌内毒素，并在孵育20小时内发生摄取后降解。
While it is generally believed that hepatic clearance of lipopolysaccharide involves Kupffer cells, the mechanism involved has not been fully elucidated. This study assesses this phenomenon in terms ofin vitrouptake and post‐uptake modification experiments with an125I‐labeledSalmonella minnesotalipopolysaccharide.125I‐Lipopolysaccharide was added to Kupffer cells in suspension cultures under a variety of conditions.In vitrouptake of125I‐Lipopolysaccharide was not saturable up to concentrations of 33.33 μg per ml. Kinetics experiments performed at 16.67 μg per ml demonstrated that Kupffer cells were unsaturable after 60 min of incubation. The kinetics of uptake could be inhibited, however, by incubation in the presence of a 10‐fold excess of unlabeled lipopolysaccharide, indicating that a component of the uptake process may be limited. Energy dependence in this process was demonstrated by incubation in the presence of 1 mM2‐deoxyglucose which inhibited125I‐lipopolysaccharide uptake by approximately 30%. Pretreatment with 7.5 × 10−5Mcolchicine had no effect on kinetics, implying no role for the cell cytoskeleton in lipopolysaccharide uptake. These results are inconsistent with a receptor‐mediated process as previously suggested. Modification of internalized label has been demonstrated by changes in buoyant density in CsCl isopyknic density gradients following overnight incubation with Kupffer cells. These results indicate that Kupffer cells clear bacterial endotoxinin vitroand post‐uptake degradation occurs within 20 hr of incubation.