Evidence for conductive Cl- pathway in the basolateral membrane of rabbit renal proximal tubule S3 segment.

The mechanism of Cl- exit was examined in the basolateral membrane of rabbit renal proximal tubule S3 segment with double-barreled, ion-selective microelectrodes. After the basolateral Cl-/HCO3- exchanger was blocked by 2'-disulfonic acid, a bath K+ step from 5 to 20 mM induced 26.6 mV depolarization and 7.7 mM increase in intracellular Cl- activities ([Cl(-)]i). K+ channel blockers, Ba2+, and quinine strongly suppressed both the response in cell membrane potentials (Vb) and in (Cl-)i to the bath K+ step, while Cl- channel blockers, A9C (1 mM) and IAA-94 (0.3 mM) inhibited only the latter response by 49 and 74%, respectively. By contrast, an inhibitor of K(+)-Cl- cotransporter, H74, had no effect on the increase in (Cl-)i to the bath K+ step. Furosemide and the removal of bath Na+ were also ineffective, suggesting that (Cl-)i are sensitive to the cell potential changes. Bath Cl- removal in the presence of quinine induced a depolarization of more than 10 mV and a decrease in (Cl-)i, and IAA-94 inhibited these responses similarly in the bath K+ step experiments. These results indicate that a significant Cl- conductance exists in the basolateral membrane of this segment and functions as a Cl- exit mechanism.

[1]  H. Sackin,et al.  Stretch- and volume-activated channels in isolated proximal tubule cells. , 1992, The American journal of physiology.

[2]  Y. Kawaguchi,et al.  A Cl- channel activated by parathyroid hormone in rabbit renal proximal tubule cells. , 1991, The Journal of clinical investigation.

[3]  M. Welsh,et al.  Calcium and cAMP activate different chloride channels in the apical membrane of normal and cystic fibrosis epithelia. , 1991, Proceedings of the National Academy of Sciences of the United States of America.

[4]  M. Goligorsky,et al.  Intracellular ramification of endothelin signal. , 1991, The American journal of physiology.

[5]  L. Schild,et al.  Basolateral transport pathways for K+ and Cl- in rabbit proximal tubule: effects on cell volume. , 1991, The American journal of physiology.

[6]  R. Frizzell,et al.  Separate Cl- conductances activated by cAMP and Ca2+ in Cl(-)-secreting epithelial cells. , 1990, Proceedings of the National Academy of Sciences of the United States of America.

[7]  C. A. Berry,et al.  Chloride transport across the basolateral membrane of rabbit proximal convoluted tubules. , 1990, The American journal of physiology.

[8]  P. Welling,et al.  Cell swelling activates basolateral membrane Cl and K conductances in rabbit proximal tubule. , 1990, The American journal of physiology.

[9]  P. Smith,et al.  Block of ATP‐regulated and Ca2(+)‐activated K+ channels in mouse pancreatic beta‐cells by external tetraethylammonium and quinine. , 1990, The Journal of physiology.

[10]  J. Ellory,et al.  Selective inhibitors of KCl cotransport in human red cells , 1990, FEBS letters.

[11]  W. Boron,et al.  Intracellular pH regulation in rabbit S3 proximal tubule: basolateral Cl-HCO3 exchange and Na-HCO3 cotransport. , 1990, American Journal of Physiology.

[12]  R. Alpern.  Cell mechanisms of proximal tubule acidification. , 1990, Physiological reviews.

[13]  M. Lipkowitz,et al.  Modulation of the ionic permeability of renal cortical brush-border membranes by cAMP. , 1989, The American journal of physiology.

[14]  M. Akabas,et al.  Purification and reconstitution of chloride channels from kidney and trachea , 1989, Science.

[15]  挾間 章博.  Ca[2+] sensitivity of volume-regulatory K[+] and Cl[-] channels in cultured human epithelial cells , 1989 .

[16]  Y. Okada,et al.  Ca2+ sensitivity of volume‐regulatory K+ and Cl‐ channels in cultured human epithelial cells. , 1988, The Journal of physiology.

[17]  S. Sasaki,et al.  Interaction of chloride and bicarbonate transport across the basolateral membrane of rabbit proximal straight tubule. Evidence for sodium coupled chloride/bicarbonate exchange. , 1988, The Journal of clinical investigation.

[18]  S. Sasaki,et al.  KCl co-transport across the basolateral membrane of rabbit renal proximal straight tubules. , 1988, The Journal of clinical investigation.

[19]  C. Ross,et al.  Cl(-)-HCO3- exchange in rat renal basolateral membrane vesicles. , 1987, Biochimica et biophysica acta.

[20]  G. Giebisch,et al.  Potassium channels in Necturus proximal tubule. , 1987, The American journal of physiology.

[21]  P. Preisig,et al.  Active and passive components of chloride transport in the rat proximal convoluted tubule. , 1985, The Journal of clinical investigation.

[22]  C. A. Berry,et al.  Evidence for neutral transcellular NaCl transport and neutral basolateral chloride exit in the rabbit proximal convoluted tubule. , 1984, The Journal of clinical investigation.

[23]  F. Rector.  Sodium, bicarbonate, and chloride absorption by the proximal tubule. , 1983, The American journal of physiology.

[24]  E. Bello‐Reuss.  Electrical properties of the basolateral membrane of the straight portion of the rabbit proximal renal tubule. , 1982, The Journal of physiology.