Weiner M W
Biochim Biophys Acta. 1980 Feb 28;596(2):292-301. doi: 10.1016/0005-2736(80)90362-4.
The association between Cl-, HCO3- and H+ transported by toad bladders was investigated. Net mucosal to serosal Cl- transport by Colombian toad bladders was stimulated by incubation in HCO3- free solutions. In addition, when Colombian or Dominican toad bladders were exposed to low HCO3- concentrations on the mucosal side and 25 mM HCO3- on the serosal side, net mucosal leads to serosal Cl- transport was induced. Neither acetazolamide nor cyanide significantly inhibited Cl- transport under these conditions. The presence of a pH gradient, more acid on the mucosal side, also induced net mucosal leads to serosal Cl- transport. The results suggest that Cl- transport by toad bladders may occur by exchange with HCO3- or OH-; this process may not require carbonic anhydrase or oxidative metabolism. The Cl- transport by toad bladders is qualitatively different from the electrogenic Cl- transport of the thick limb of Henle's loop, but may be similar to a process which occurs in other portions of the nephron.
研究了蟾蜍膀胱所转运的Cl⁻、HCO₃⁻和H⁺之间的关联。在无HCO₃⁻溶液中孵育可刺激哥伦比亚蟾蜍膀胱从黏膜向浆膜的净Cl⁻转运。此外，当哥伦比亚或多米尼加蟾蜍膀胱黏膜侧暴露于低HCO₃⁻浓度、浆膜侧暴露于25 mM HCO₃⁻时，可诱导从黏膜到浆膜的净Cl⁻转运。在这些条件下，乙酰唑胺和氰化物均未显著抑制Cl⁻转运。存在pH梯度（黏膜侧更酸）也可诱导从黏膜到浆膜的净Cl⁻转运。结果表明，蟾蜍膀胱的Cl⁻转运可能通过与HCO₃⁻或OH⁻交换而发生；该过程可能不需要碳酸酐酶或氧化代谢。蟾蜍膀胱的Cl⁻转运在性质上不同于亨氏袢厚壁段的电生性Cl⁻转运，但可能类似于在肾单位其他部分发生的过程。
