Putrescine uptake and release by colon cancer cells.
Putrescine uptake and release by colon cancer cells.
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结肠癌细胞摄取和释放腐胺。
DOI：
10.1152/ajpgi.1989.256.5.g868
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Johnson,LR
中科院分区：
文献类型：
--
作者：
McCormack,SA;Johnson,LR
我们已经调查了[3 H]腐胺的摄取和释放的人结肠腺癌细胞系（LoVo）保持在过滤器插入。该培养系统允许细胞形成形态极性，并提供了通向细胞基底外侧和顶端表面的单独通路。[3 H]腐胺更容易被细胞的基底侧比顶端侧吸收。10 mM天冬酰胺或10%胎牛血清可刺激[3 H]腐胺摄取300倍以上。[3 H]腐胺积累到约300倍的浓度梯度;摄取可被7.5 μ M未标记腐胺抑制50%，并且不依赖于Na+。天冬酰胺或胎牛血清可抑制[~ 3 H]腐胺向根尖培养基中的释放。通常，少于千分之一的[3 H]腐胺被吸收到细胞中释放到顶端介质中。[3 H]腐胺的释放并不对应于[14 C]-菊糖在顶端介质中的积累。由于这些原因，我们得出结论，腐胺的释放不是简单的被动泄漏，而是响应细胞内的需求。在4 h时，由细胞吸收的[3 H]腐胺以及释放到顶端培养基中的腐胺大于90%未代谢。
We have investigated the uptake and release of [3H]putrescine by a human colon adenocarcinoma cell line (LoVo) maintained on filter inserts. This culture system permits the cells to develop morphological polarity and provides separate access to the basolateral and apical surfaces of the cells. [3H]putrescine was taken up more readily by the basolateral than by the apical side of the cells. [3H]putrescine uptake could be stimulated greater than 300 times by either 10 mM asparagine or 10% fetal bovine serum. [3H]putrescine was accumulated to a concentration gradient of approximately 300-fold; uptake could be inhibited 50% by 7.5 microM unlabeled putrescine and was not dependent on Na+. The release of [3H]putrescine into the apical medium was inhibited by asparagine or fetal bovine serum. Usually, less than one-thousandth of the [3H]putrescine taken up into the cells was released into the apical medium. Release of [3H]putrescine did not correspond to the accumulation of [14C]-inulin in the apical medium. For these reasons we concluded that putrescine release was not simply passive leakage but was responsive to intracellular demand. The [3H]putrescine taken up by the cells as well as that released into the apical medium was greater than 90% unmetabolized at 4h.