DIPHENYLAMINE-2-CARBOXYLATE, A BLOCKER OF THE CL--CONDUCTIVE PATHWAY IN CL--TRANSPORTING EPITHELIA
DIPHENYLAMINE-2-CARBOXYLATE, A BLOCKER OF THE CL--CONDUCTIVE PATHWAY IN CL--TRANSPORTING EPITHELIA
复制标题
DOI：
10.1007/bf00581787
复制
发表时间：
1985-01-01
影响因子：
4.5
通讯作者：
GREGER, R
中科院分区：
文献类型：
--
作者：
DISTEFANO, A;WITTNER, M;GREGER, R
本研究考察了二苯胺-2-羧酸盐（DPC）在Cl−转运上皮细胞中的作用。这种物质可逆地阻断正常情况下存在于亨利氏袢（TAL）的厚上升肢的基底外侧膜和鲨鱼直肠腺小管（RGT）的顶膜中的Cl−传导。这导致减少在积极的NaCl重吸收（TAL）和NaCl分泌（RGT），分别由等效短路电流测量。当膜电压从控制值（Cl−和K+的化学势之间的某种折衷）向K+的化学势漂移时，细胞会过度增殖。基底外侧膜（TAL）或顶膜（RGT）的电阻增加，这导致跨上皮电阻中度增加。此外，Cl−浓度阶跃诱导的膜电压变化（可在控制条件下产生）在阻断剂存在下消失。最后，在离体细胞膜上的实验表明，这种物质抑制了单个Cl−通道的单一电流事件。
The present study examines the effects of diphenylamine-2-carboxylate (DPC) in Cl−-transporting epithelia. This substance blocks reversibly the Cl−-conductance present under normal circumstances in the basolateral membrane of the thick ascending limb of the loop of Henle (TAL) and in the apical membrane of shark rectal gland tubules (RGT). This leads to a reduction in active NaCl reabsorption (TAL) and NaCl secretion (RGT) respectively, as measured by the equivalent short circuit current. The cells hyperpolarize as the membrane voltage drifts from the control value (some compromise between the chemical potential of Cl−and K+) towards the chemical potential of K+. The resistance of the basolateral (TAL) or apical membrane (RGT) increases and this leads to a moderate increase in transepithelial resistance. In addition, the Cl−-concentration step induced membrane voltage changes, which can be produced under control conditions, disappear in the presence of the blocker. Finally, experiments in excised membrane patches indicate that this substance inhibits the single current events of individual Cl−-channels.