Perrone R D, Alexander E A, Bengele H H, Schwartz J H
Pflugers Arch. 1984 Mar;400(3):257-61. doi: 10.1007/BF00581556.
Aldosterone and dexamethasone stimulate sodium absorption in the rat colon in vivo. In vitro, increased amiloride inhibitable short-circuit current (ISC) has been demonstrated following aldosterone or dexamethasone treatment. Since ISC bears no relationship to sodium flux (JNa) in the untreated rat colon, we measured JNa in partially stripped voltage clamped segments of rat distal colon. Our results demonstrate directly that continuous infusion of aldosterone or dexamethasone for 4-7 days stimulated amiloride inhibitable JNa by stimulating JNaM -S. The amiloride inhibitable portion of JNaM -S was highly correlated with and approximately equal to the amiloride inhibitable ISC. Amiloride had no effect in controls. We conclude that JNaM -S in the rat distal colon is only sensitive to mucosal amiloride after treatment with aldosterone or dexamethasone. The amiloride sensitive ISC in these treated tissues was a good measure of the amiloride sensitive JNa. Small differences between aldosterone and dexamethasone treatment were noted in the effect on transepithelial resistance, potential difference, and the ISC after amiloride.
醛固酮和地塞米松可刺激大鼠结肠在体内吸收钠。在体外，醛固酮或地塞米松处理后已证明氨氯吡咪可抑制的短路电流（ISC）增加。由于在未处理的大鼠结肠中ISC与钠通量（JNa）无关，我们在大鼠远端结肠部分剥离的电压钳制节段中测量了JNa。我们的结果直接表明，连续输注醛固酮或地塞米松4 - 7天通过刺激JNaM - S来刺激氨氯吡咪可抑制的JNa。JNaM - S的氨氯吡咪可抑制部分与氨氯吡咪可抑制的ISC高度相关且大致相等。氨氯吡咪对对照组无影响。我们得出结论，大鼠远端结肠中的JNaM - S仅在醛固酮或地塞米松处理后对黏膜氨氯吡咪敏感。这些处理过的组织中氨氯吡咪敏感的ISC是氨氯吡咪敏感JNa的良好指标。在对跨上皮电阻、电位差和氨氯吡咪处理后的ISC的影响方面，注意到醛固酮和地塞米松处理之间存在微小差异。
