Flemström G
Ups J Med Sci. 1979;84(2):137-44. doi: 10.3109/03009737909179149.
Luminal to submucosal migration of 14C-acetylsalicylate and D-lactate and some electrical properties were studied in isolated frog gastric mucosae. With both compounds, the unionized acids permeated much more rapidly than the ionized conjugate bases. The permeability coefficient for unionized acetylsalicylic acid increased from 0.27 to 0.43 mumoles, h-1, cm-2, mM-1 when its luminal concentration was increased above 3 mM. Simultaneously there was an increase in mucosal ion conductance. Acetylsalicylic acid has been shown previously to increase gastric mucosal permeation of ions and uncharged larger molecules. The present results indicate that above a threshold concentration the unionized form also enhances absorption of this drug per se. Unionized D-lactic acid had no effect of mucosal ion conductance and the permeability coefficient (0.07 mumoles, h-1, cm-2, mM-1) was independent of its luminal concentration.
在离体蛙胃黏膜中研究了14C - 乙酰水杨酸和D - 乳酸从管腔向黏膜下层的迁移以及一些电特性。对于这两种化合物，未解离的酸比离子化的共轭碱渗透得快得多。当管腔浓度增加到3 mM以上时，未解离乙酰水杨酸的渗透系数从0.27增加到0.43微摩尔·小时-1·厘米-2·毫摩尔-1。同时，黏膜离子电导增加。先前已表明乙酰水杨酸可增加胃黏膜对离子和不带电荷的大分子的通透性。目前的结果表明，高于阈值浓度时，未解离形式本身也会增强该药物的吸收。未解离的D - 乳酸对黏膜离子电导没有影响，其渗透系数（0.07微摩尔·小时-1·厘米-2·毫摩尔-1）与管腔浓度无关。
