Iwatsubo T, Miyamoto Y, Sugiyama Y, Yuasa H, Iga T, Hanano M
J Pharm Sci. 1986 Dec;75(12):1162-5. doi: 10.1002/jps.2600751209.
This study was designed to determine the pH of the intestinal surface in the rat jejunum in an attempt to investigate the effect of potential damaging agents on the microclimate-pH. A significant pH gradient was observed between the mucosal surface and the bulk phase; however, the microclimate-pH usually ranged from 6.5 to 7.5, irrespective of the wide range in the bulk pH. When the bulk pH was either 7.3 or 4, the microclimate-pH was approximately 6.7, while the microclimate-pH was approximately 7.4 when the bulk pH was raised to 9. The distance of the pH gradient was found to be approximately 900-1300 microns. After treatment with ouabain (10 mM) or amiloride (8 mM), or replacement of Na+ with Li+, the microclimate-pH significantly increased compared with the control (buffer solution). Chlorpromazine (2 mM) and ouabain also significantly increased the microclimate-pH, but at the same time, chlorpromazine decreased the bulk pH so that a more marked pH gradient was observed. Both aspirin (10 mM) and acetazolamide (80 mg/kg, iv) significantly decreased the microclimate-pH under the condition of the acidic bulk phase pH. N-Acetyl-L-cysteine (5%) induced marked changes in microclimate-pH, the direction depending upon the bulk phase pH. Neither taurocholic acid (10 mM) nor glucose (10 mM) significantly changed the microclimate pH.
本研究旨在测定大鼠空肠肠表面的pH值，以探讨潜在损伤剂对微环境pH值的影响。在黏膜表面和主体相之间观察到显著的pH梯度；然而，无论主体相pH值范围有多宽，微环境pH值通常在6.5至7.5之间。当主体相pH值为7.3或4时，微环境pH值约为6.7，而当主体相pH值升至9时，微环境pH值约为7.4。发现pH梯度的距离约为900 - 1300微米。用哇巴因（10 mM）或氨氯吡咪（8 mM）处理后，或用Li +替代Na +后，与对照（缓冲溶液）相比，微环境pH值显著升高。氯丙嗪（2 mM）和哇巴因也显著提高了微环境pH值，但同时氯丙嗪降低了主体相pH值，因此观察到更明显的pH梯度。在酸性主体相pH值条件下，阿司匹林（10 mM）和乙酰唑胺（80 mg/kg，静脉注射）均显著降低了微环境pH值。N - 乙酰 - L - 半胱氨酸（5%）引起微环境pH值的显著变化，其方向取决于主体相pH值。牛磺胆酸（10 mM）和葡萄糖（10 mM）均未显著改变微环境pH值。
