UNUSUAL PERMEABILITY PROPERTIES OF GASTRIC GLAND-CELLS
UNUSUAL PERMEABILITY PROPERTIES OF GASTRIC GLAND-CELLS
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DOI：
10.1038/368332a0
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发表时间：
1994-03-24
期刊：
影响因子：
64.8
通讯作者：
BORON, WF
中科院分区：
文献类型：
--
作者：
WAISBREN, SJ;GEIBEL, JP;BORON, WF
生理学家长期以来一直在思考为什么胃本身不能被它分泌的汁液消化。一种解释是粘液-碳酸氢盐屏障，覆盖胃腔以及胃腺的浅表部分，防止自身消化（1）。然而，这留下了一个未回答的问题，即是什么保护了腺体深处的细胞，这些细胞似乎缺乏粘液屏障（2）。这些是壁细胞和主细胞，分泌酸和胃蛋白酶。使用灌注的兔单个胃腺，我们最近发现，细胞内pH值对极端程度的管腔酸化具有独特的抵抗力（2），这表明顶端（管腔）屏障也可能排除氨和二氧化碳，细胞膜通常具有高度渗透性（3，4）。我们现在证明情况确实如此。有三种膜对NH3的渗透性非常低（参考文献5-7），没有一种膜对CO2是不可渗透的。
PHYSIOLOGISTS have long pondered the riddle of why the stomach is itself not digested by the very juice it secretes. One explanation is that a mucus-bicarbonate barrier, coating the stomach lumen as well as superficial portions of gastric glands, prevents autodigestion(1). However, this leaves unanswered the question of what protects cells deeper in the glands, which seem to lack a mucus barrier(2). These are the parietal and chief cells, which secrete acid and pepsin. Using perfused single gastric glands from rabbit, we recently found that intracellular pH is uniquely resistant to extreme degrees of luminal acidification(2), suggesting that the apical (luminal) barrier might also exclude ammonia and carbon dioxide, to which cell membranes are generally highly permeable(3,4). We now show that this is indeed the case. There are three reports of membranes with very low permeabilities to NH3 (refs 5-7), and none of membranes impermeable to CO2.