Ericson A C, Spring K R
Am J Physiol. 1982 Sep;243(3):C146-50. doi: 10.1152/ajpcell.1982.243.3.C146.
Necturus gallbladder epithelial cells exhibited volume regulatory swelling when exposed to a hypertonic mucosal bathing solution. The initial, osmotically induced shrinkage was followed by a rapid increase in cell volume back to the control value despite continuing hypertonicity of the mucosal perfusate. This volume regulatory increase occurred by osmotic water flow accompanying the transient cellular uptake of NaCl from the mucosal bathing solution. Volume regulatory increase required Na+ and Cl- in the mucosal bath; it was inhibited by amiloride or 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid but not by bumetanide or ouabain. The K1/2 for Na+ was 2.8 mM, the K1/2 for Cl- was 1.9 mM, and maximum velocity of fluid flow into the cell for both ions was greater than 10 x 10(-6) cm/s. Both volume regulatory increase and transepithelial fluid absorption involve NaCl flux across the apical membrane into the cells, but the nature of the NaCl fluxes differ in the two processes. During volume regulatory increase NaCl enters the cells by parallel Na+-H+ and Cl(-)-HCO-3 exchanges, whereas during transepithelial fluid absorption NaCl enters the cell by the coupled flux of NaCl.
美西螈胆囊上皮细胞在暴露于高渗性黏膜灌流液时会出现容积调节性肿胀。最初由渗透压诱导的细胞收缩之后，尽管黏膜灌流液持续处于高渗状态，但细胞体积会迅速增加回到对照值。这种容积调节性增加是通过伴随从黏膜灌流液中短暂摄取NaCl的渗透水流实现的。容积调节性增加需要黏膜灌流液中有Na⁺和Cl⁻；它受到氨氯吡脒或4-乙酰氨基-4'-异硫氰基芪-2,2'-二磺酸的抑制，但不受布美他尼或哇巴因的抑制。Na⁺的K1/2为2.8 mM，Cl⁻的K1/2为1.9 mM，两种离子流入细胞的最大流体流速均大于10×10⁻⁶ cm/s。容积调节性增加和跨上皮液体吸收都涉及NaCl通过顶膜进入细胞，但在这两个过程中NaCl通量的性质不同。在容积调节性增加过程中，NaCl通过平行的Na⁺-H⁺和Cl⁻-HCO₃⁻交换进入细胞，而在跨上皮液体吸收过程中，NaCl通过NaCl的耦联通量进入细胞。
