体外人胃黏膜表面黏液层pH梯度的证明。
Demonstration of a pH gradient across the mucus layer on the surface of human gastric mucosa in vitro.
作者信息
Bahari H M, Ross I N, Turnberg L A
出版信息
Gut. 1982 Jun;23(6):513-6. doi: 10.1136/gut.23.6.513.
In previous studies we have demonstrated a hydrogen ion concentration gradient across the mucus on rat and rabbit fundic mucosa, in vivo and in vitro respectively, observations which support the possibility of a 'mucus-bicarbonate' protective barrier. In the present studies we have demonstrated a similar gradient across the mucus on human gastric mucosa in vitro. The minimum mean hydrogen ion concentration at the mucus-epithelium interface was 1 . 1 X 10(-4) mM (pH 6 . 96, n = 10) when the luminal concentration was 5 . 6 mM (pH 2 . 25). Aspirin (10 mM) and N-acetyl cysteine (306 mM) (5%) increased the minimum intra-mucus hydrogen ion concentration and the gradient was overwhelmed by a luminal hydrogen ion concentration of 40 mM (pH 1 . 4). These results suggest that a hydrogen ion concentration gradient exists across the mucus on human gastric mucosa and that potential damaging agents may act by compromising one or other of th components of this 'mucus-alkaline', presumed 'mucus-bicarbonate', barrier.
在先前的研究中，我们分别在体内和体外证明了大鼠和兔胃底黏膜黏液层存在氢离子浓度梯度，这些观察结果支持了“黏液-碳酸氢盐”保护屏障存在的可能性。在本研究中，我们在体外证明了人胃黏膜黏液层也存在类似的梯度。当管腔浓度为5.6 mM（pH 2.25）时，黏液-上皮界面处的最低平均氢离子浓度为1.1×10⁻⁴ mM（pH 6.96，n = 10）。阿司匹林（10 mM）和N-乙酰半胱氨酸（306 mM）（5%）会增加黏液层内的最低氢离子浓度，当管腔氢离子浓度为40 mM（pH 1.4）时，该梯度会被打破。这些结果表明，人胃黏膜黏液层存在氢离子浓度梯度，潜在的损伤因子可能通过破坏这种假定的“黏液-碱性”（即“黏液-碳酸氢盐”）屏障的一个或其他成分而起作用。
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