Husted R F, Steinmetz P R
J Pharmacol Exp Ther. 1979 Aug;210(2):264-8.
To investigate the mechanism by which amiloride inhibits urinary acidification, its effects on H+ secretion were examined in the isolated urinary bladder of the fresh water turtle. In short-circuited turtle bladders amiloride inhibited H+ secretion by 30% and Na+ transport by 100%. Maximal inhibition was reached at 10(-4) M amiloride for both transport systems. In contrast to amiloride, ouabain did not affect H+ secretion despite complete inhibition of Na+ transport. In bladders first treated with ouabain amiloride failed to inhibit H+ secretion and in bladders first treated with amiloride, the inhibition of H+ secretion was partially reversed by ouabain. The inhibition of H+ secretion by amiloride is attributed to hyperpolarization of the luminal cell membrane and the imposition of a voltage opposing the movement of protons in the active transport pathway.
为了研究氨氯吡咪抑制尿酸化的机制，在淡水龟的离体膀胱中检测了其对H⁺分泌的影响。在短路的龟膀胱中，氨氯吡咪抑制H⁺分泌30%，抑制Na⁺转运100%。两种转运系统在10⁻⁴M氨氯吡咪时均达到最大抑制。与氨氯吡咪不同，哇巴因尽管完全抑制了Na⁺转运，但不影响H⁺分泌。在用哇巴因预处理的膀胱中，氨氯吡咪不能抑制H⁺分泌；而在用氨氯吡咪预处理的膀胱中，哇巴因可部分逆转H⁺分泌的抑制作用。氨氯吡咪对H⁺分泌的抑制作用归因于管腔细胞膜的超极化以及在主动转运途径中施加了一个与质子移动方向相反的电压。
