Degnan K J
J Exp Zool. 1984 Jul;231(1):11-7. doi: 10.1002/jez.1402310103.
The effects of ion substitutions on the Cl- secretion rate and tissue conductance of isolated short-circuited opercular epithelia from sea-water-adapted Fundulus heteroclitus were investigated. Serosal Na+ substitution had the same effect on the Cl- secretion rate that serosal Cl- substitution had on the active component of the Cl- efflux. This similarity indicated a 1:1 Na-Cl requirement for active Cl- secretion across this epithelium, which supports the proposal of a coupled NaCl uptake mechanism at the serosal membrane of Cl- secretory epithelia. Mucosal Na+ and Cl- substitutions appeared to inhibit completely the active Cl- secretory flux. The reductions in the tissue conductance with mucosal ion substitutions suggested that this effect can be attributed to a blocking of the apical membrane Cl- conductance. These mucosal ion effects suggested a possible direct regulatory influence of the external salinity on the Cl- secretion rate and tissue conductance, which provide alternative explanations for observations with the teleost gill epithelium.
研究了离子替代对来自海水适应的异鳞鳉离体短路鳃盖上皮细胞的氯离子分泌速率和组织电导率的影响。浆膜钠离子替代对氯离子分泌速率的影响与浆膜氯离子替代对氯离子外流活性成分的影响相同。这种相似性表明，跨该上皮细胞进行活性氯离子分泌时，钠离子与氯离子的需求比例为1:1，这支持了氯离子分泌上皮细胞浆膜存在耦合氯化钠摄取机制的提议。黏膜钠离子和氯离子替代似乎完全抑制了活性氯离子分泌通量。黏膜离子替代导致组织电导率降低，这表明这种效应可归因于顶端膜氯离子电导率的阻断。这些黏膜离子效应表明，外部盐度可能对氯离子分泌速率和组织电导率有直接调节作用，这为硬骨鱼鳃上皮细胞的观察结果提供了其他解释。
