Electroneutral secretion of bicarbonate by guinea pig gallbladder epithelium.
Electroneutral secretion of bicarbonate by guinea pig gallbladder epithelium.
复制标题
豚鼠胆囊上皮细胞电中性分泌碳酸氢盐。
DOI：
10.1152/ajpcell.1986.250.4.c617
复制
发表时间：
1986
期刊：
影响因子：
--
通讯作者：
K. Petersen
中科院分区：
文献类型：
--
作者：
J. Winterhager;C. P. Stewart;K. Heintze;K. Petersen
本文研究了豚鼠离体胆囊中HCO_3 ~-的跨上皮运动。吸收（JHCO 3 ms）和分泌（JHCO 3sm）HCO 3-通量，通过使用的pH-统计方法测定分别为约1.0和2.1 μ mol × cm-2 × h-1，分别。Cl-净吸收超过Na+的量依赖于管腔Cl-和血清Na+，并被粘膜4-乙酰氨基-4 '-异硫氰基二苯乙烯-2，2'-二磺酸抑制（SITS; 10（-3）M）和舍曲哇巴因（3 × 10（-5）M），但舍曲阿米洛利（10（-3）M）不能，双侧醋甲唑胺（10（-4）M）几乎不能。JHCO 3 ms被粘膜Cl-降低，但被Serpine Cl-增强;它依赖于粘膜Na+，并被粘膜阿米洛利和双侧醋甲唑胺抑制。我们的研究结果与以下模型一致：1）血清HCO 3-与Na+共转运进入细胞，然后通过顶膜的Cl-（-）HCO 3-交换被挤出到管腔中; 2）粘膜HCO 3-在顶膜Na+-H+交换后进入细胞，并通过Cl-（-）HCO 3-交换进入管腔，或者在较小程度上通过基底侧膜吸收。
Transepithelial HCO3- movement in guinea pig gallbladder was investigated in vitro. Absorptive (JHCO3ms) and secretory (JHCO3sm) HCO3- fluxes, determined by use of the pH-stat method were approximately 1.0 and 2.1 mumol X cm-2 X h-1, respectively. The resultant net secretion equaled in magnitude, and balanced electrically, the excess in net absorption of Cl- over that of Na+ X JHCO3sm was dependent on luminal Cl- and serosal Na+; it was inhibited by mucosal 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS; 10(-3) M) and serosal ouabain (3 X 10(-5) M) but not by serosal amiloride (10(-3) M) and scarcely by bilateral methazolamide (10(-4) M). JHCO3ms was reduced by mucosal Cl- but enhanced by serosal Cl-; it was dependent on mucosal Na+ and inhibited by mucosal amiloride and bilateral methazolamide. Our findings are consistent with a model in which 1) serosal HCO3- enters the cell in cotransport with Na+ and is then extruded into the lumen by Cl-(-)HCO3- exchange at the apical membrane; 2) mucosal HCO3- enters the cell secondary to apical membrane Na+-H+ exchange and recycles into the lumen via Cl-(-)HCO3- exchange or is, to a lesser extent, absorbed across the basolateral membrane.