Alcohol causes both tolerance and sensitization of rat Kupffer cells via mechanisms dependent on endotoxin
Alcohol causes both tolerance and sensitization of rat Kupffer cells via mechanisms dependent on endotoxin
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DOI：
10.1016/s0016-5085(98)70211-2
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发表时间：
1998-08-01
期刊：
影响因子：
29.4
通讯作者：
Thurman, RG
中科院分区：
文献类型：
--
作者：
Enomoto, N;Ikejima, K;Thurman, RG
背景与目的：乙醇对Kupffer细胞既有耐受性，又有敏化作用。这项研究旨在评估乙醇的时间效应，试图理解这一悖论。方法：给大鼠灌胃乙醇(4g/kg体重)，0~48h后分离库普弗细胞。加入脂多糖后，用荧光指示剂Fura-2荧光分光光度计测细胞内钙离子浓度([Ca~(2+)](I))，用双抗体夹心法测定肿瘤坏死因子-α(TNF-α)。采用Western和Northern分析方法对CD14进行鉴定。结果：乙醇作用2小时后，内毒素诱导的枯否细胞[Ca~(2+)](I)和肿瘤坏死因子-α(TNF-α)释放量增加50%，24小时后增加一倍。用抗生素消毒肠道可完全阻断乙醇对[Ca~(2+)](I)和肿瘤坏死因子-α释放的所有影响。酒精作用24小时后，Kupffer细胞中的CD14升高了约5倍。结论：乙醇早期分离的大鼠Kupffer细胞对内毒素具有耐受性，但在以后观察到致敏作用。这两种现象很可能都是由肠源性内毒素引起的，库普弗细胞的敏化是由CD14的增加引起的。
Background & Aims: Ethanol causes both tolerance and sensitization of Kupffer cells. This study was designed to evaluate temporal effects of ethanol in an attempt to understand this paradox. Methods: Rats were given ethanol (4 g/kg body wt) intragastrically, and Kupffer cells were isolated 0-48 hours later. After addition of lipopolysaccharide (LPS), intracellular calcium concentration ([Ca2+](i)) was measured using a microspectrofluorometer with the fluorescent indicator fura-2, and tumor necrosis factor alpha (TNF-alpha) was measured by enzyme-linked immunosorbent assay. CD14 was evaluated by Western and Northern analysis. Results: Two hours after ethanol administration, the LPS-induced increase in [Ca2+](i) and TNF-alpha release by Kupffer cells was diminished by 50%, and these parameters were reciprocally enhanced twofold at 24 hours. Sterilization of the gut with antibiotics blocked all effects of ethanol on [Ca2+](i) and TNF-alpha release completely. Twenty-four hours after ethanol, CD14 in Kupffer cells was elevated about fivefold. Conclusions: Kupffer cells isolated from rats early after ethanol exhibited tolerance to LPS, whereas sensitization was observed later. It is likely that both of these phenomena are caused by gut-derived endotoxin and that sensitization in Kupffer cells is caused by increases in CD14.