Effects of endotoxin on iron uptake by the hepatocyte.
Effects of endotoxin on iron uptake by the hepatocyte.
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内毒素对肝细胞铁摄取的影响。
DOI：
10.1152/ajpgi.1989.257.4.g524
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Rand,JH
中科院分区：
文献类型：
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作者：
Potter,BJ;Blades,B;McHugh,TA;Nunes,RM;Beloqui,O;Slott,PA;Rand,JH
内毒素通常在12-24小时内出现明显的低铁血症。由于肝细胞是铁储存和转铁蛋白合成的主要部位，我们研究了大肠杆菌内毒素（脂多糖，LPS）对正常Wistar大鼠（ND）、以前腹腔注射2.5 mg/kg （LD）或25 mg/kg (HD) LPS的大鼠和腹腔注射无菌生理盐水（CD）的对照大鼠分离的肝细胞的这些参数的影响。用350微克LPS/10(7)个肝细胞体外培养ND细胞，未观察到对转铁蛋白铁摄取的影响。注射LPS后1小时，CD、HD和LD肝细胞对铁的摄取也无显著差异。然而，LPS处理后24小时分离的肝细胞吸收铁的速度明显快于对照组。HD和LD肝细胞在24小时内对非转铁蛋白结合的铁的摄取也增加，但只有HD细胞在1小时时才增加。注射后1小时和24小时，lps处理的ND大鼠细胞的转铁蛋白结合没有改变，但在lps处理的大鼠细胞中，转铁蛋白结合被抑制。在LD和HD大鼠细胞中，24 h转铁蛋白受体循环明显增加。在LPS处理的大鼠中，转铁蛋白和总蛋白的合成在1 h时也受到抑制，在24 h时恢复到正常水平。然而，直接预孵育ND细胞，除了在最高浓度的LPS下，没有增加合成。我们得出结论，LPS对肝细胞的蛋白质合成有直接的（尽管是间接的）影响，但对铁的摄取没有影响。（摘要删节250字）
Administration of endotoxins is often followed within 12-24 h by marked hypoferremia. Because the hepatocyte is the major site of both iron storage and transferrin synthesis, we have investigated the effects of an Escherichia coli endotoxin (lipopolysaccharide, LPS) on these parameters on isolated hepatocytes from normal Wistar rats (ND), rats previously treated intraperitoneally with 2.5 mg/kg (LD) or 25 mg/kg (HD) LPS, and control rats injected intraperitoneally with sterile saline (CD). No effects were observed on iron uptake from transferrin by ND cells incubated in vitro with up to 350 micrograms LPS/10(7) hepatocytes. There was also no significant difference in iron uptake between CD, HD, and LD hepatocytes 1 h after LPS injection. However, hepatocytes isolated 24 h after LPS administration took up iron significantly faster than controls. The uptake of non-transferrin-bound iron was also increased in HD and LD hepatocytes at 24 h but only in HD cells at 1 h. Transferrin binding was not altered in LPS-treated cells from ND rats but was depressed in cells from LPS-treated rats both at 1 h and at 24 h after injection. Transferrin receptor recycling was significantly increased at 24 h in cells from both LD and HD rats. Transferrin and total protein synthesis were also depressed at 1 h in LPS-treated rats, returning to normal values at 24 h. Direct preincubation of ND cells, however, failed to increase synthesis except at the highest concentrations of LPS. We conclude that LPS has an immediate (although indirect) effect on protein synthesis by the hepatocyte but not on iron uptake.(ABSTRACT TRUNCATED AT 250 WORDS)