Abstract
The membrane potential V m the cytosolic pH (pHi), the transference numbers (t) for K+, Cl− and Na+/ non-selective cation (NSC) and the pH-sensitivity of V m were investigated in transitional cells from the vestibular labyrinth of the gerbil. V m, pHi, \(t_{K^ + } , t_{Cl^ - } , t_{Na^ + /NSC} \), and the pHi sensitivity of V m were under control conditions were −92±1 mV (n=89 cells), pHi 7.13±0.07 (n=11 epithelia), 0.87±0.02 (n=22), 0.02±0.01 (n=19), 0.01±0.01 (n=24) and −5 mV/pH unit (n=13 cells/n=11 epithelia), respectively. In the presence of 100 μmol/l Ba2+ the corresponding values were: −70±1 mV (n=32), pHi 7.16±0.08 (n=6), 0.31±0.05 (n=4), 0.06±0.01 (n=6), 0.20±0.03 (n=10) and -16 mV/pH-unit (n=15/n=6). In the presence of 500 μmol/l amiloride the corresponding values were: −72±2mV (n=34), pHi 7.00±0.07 (n=5), 0.50±0.04 (n=6), 0.04±0.01 (n=11), 0.28±0.04 (n=9) and −26 mV/pH-unit (n=20/n=5). In the presence of 20 mmol/l propionate plus amiloride the corresponding values were: −61±2 mV (n=27), pHi 6.72±0.06 (n=5), 0.30±0.02 (n=6), 0.06±0.01 (n=5) and 0.40±0.02 (n=8), respectively. V m was depolarized and \(t_{K^ + } \) and pHi decreased due to (a) addition of 1 mmol/l amiloride in 150 mmol/l Na+ by 38±1 mV (n=8), from 0.82±0.02 to 0.17±0.02 (n=8) and by 0.13±0.01 pH unit (n=6), respectively; (b) reduction of [Na+] from 150 to 1.5 mmol/l by 3.3±0.5 mV (n=30), from 0.83±0.02 to 0.75±0.04 (n=9) and by 0.33±0.07 pH unit (n=4), respectively and (c) addition of 1 mmol/l amiloride in 1.5 mmol/l Na+ by 20±1 mV (n=11) and from 0.83±0.03 to 0.53±0.02 (n=5), respectively. These data suggest that the K+ conductance is directly inhibited by amiloride and Ba2+ and that Ba2+ and amiloride uncover or induce a pH-sensitive and a Na+/NSC conductance which may or may not be the same entity.
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References
Aronson PS (1985) Kinetic properties of the plasma membrane Na+/H+ exchanger. Annu Rev Physiol 47:545–560
Beck JS, Breton S, Giebisch G, Laprade R (1992) Potassium conductance regulation by pH during volume regulation in rabbit proximal convoluted tubules. Am J Physiol 263:F453-F458
Burckhardt BC, Kroll B, Frömter E (1992) Proton transport mechanism in the cell membrane of Xenopus laevis oocytes. Pflügers Arch 420:78–82
Discala F, Belachgar F, Planelles G, Hulin P, Anagnostopoulos T (1992) Barium- or quinine-induced depolarization activates K, Na, and cationic conductances in frog proximal tubular cells. J Physiol (Lond) 448:525–537
Discala F, Hulin P, Belachgar F, Planelles G, Edelman A, Anagnostopoulos T (1992) Millimolar amiloride concentrations block K conductance in proximal tubular cells. Br J Pharmacol 107:532–538
Gögelein H, Greger R, Schlatter E (1987) Potassium channels in the basolateral membrane of the rectal gland of Squalus acanthias. Regulation and inhibitors. Pflügers Arch 409: 107–113
Granitzer M, Leal T, Nagal W, Crabbe J (1991) Apical and basolateral conductance in cultured A6 cells. Pflügers Arch 417:463–468
Greger R, Bleich M, Schlatter E (1991) Ion channel regulation in the thick ascending limb of the loop of Henle. Kidney Int 40 (Suppl 33):S119-S124
Hurst AM, Hunter M (1989) Apical K+ channels of frog diluting segment: inhibition by acidification. Pflügers Arch 415:115–117
Kaczorowski GJ, Barros F, Dethmers JK, Trumble MJ, Cragoe EJ (1985) Inhibition of the Na+/Ca2+ exchange in pituitary plasma membrane vesicles by analogues of amiloride. Biochemistry 24:1394–1403
Keller SK, Jentsch TJ, Koch M, Wiederholt M (1986) Interactions of pH and K+ conductance in cultured bovine pigment epithelial cells. Am J Physiol 250:C124–C137
Korbmacher C, Helbig H, Forster C, Wiederholt M (1988) Evidence for Na+/H+ exchanger and pH sensitive membrane voltage in cultured bovine corneal epithelial cells. Curr Eye Res 7:619–626
Light DB, McCann FV, Keller TM, Stanton BA (1988) Amilo-ride-sensitive cation channel in apical membrane of inner medulary collecting duct. Am J Physiol 255:F278-F286
Lindemann B, Driessche W van (1977) Sodium-specific membrane channels in frog skin are pores: current fluctuations reveal high turnover. Science 195:292–294
Marcus DC, Takeuchi S, Wangemann P (1992) Ca2+-activated nonselective cation channel in apical membrane of vestibular dark cells. Am J Physiol 262:C1423–C1429
Marcus DC, Takeuchi S, Wangemann P (1993) Two types of chloride channel in the basolateral membrane of vestibular dark cells. Hear Res 69:124–132
Marcus NY, Marcus DC (1985) Transepithelial cation movements in Gerbil utricles. Am J Otolaryngol 6:268–274
Nagel W (1977) The dependence of the electrical potentials across the membranes of the frogskin upon the concentration of sodium in the mucosal secretion. J Physiol (Lond) 269:777–796
Nagel W, Driessche W van (1989) Intracellular potentials of toad urinary bladder. Pflügers Arch 415:121–123
Nagel W, Garcia-Diaz JF, Armstrong WM (1981) Intracellular ionic activities in frog skin. J Membr Biol 61:127–134
Oberleithner H, Munich G, Schwab A, Dietl P (1986) Amiloride reduced potassium conductance in frog kidney via inhibition of Na+-H+ exchange. Am J Physiol 251:F66-F73
Oberleithner H, Kersting U, Hunter M (1988) Cytoplasmic pH determines K+ conductance in fused renal epithelial cells. Proc Natl Acad Sci USA 85:8345–8349
Ohnu-Shosaku T, Kubota T, Yamaguchi J, Fujimoto M (1990) Regulation of inwardly rectifying K+ channels by intracellular pH in opossum kidney cells. Pflügers Arch 416:138–143
Palmer LG (1987) Ion selectivity of epithelial Na+ channels. J Membr Biol 96:97–106
Palmer LG, Frindt G (1986) Amiloride-sensitive Na channels from the apical membrane of the rat cortical collecting tubule. Proc Natl Acad Sci USA 83:2767–2770
Schwegler JS, Steigner W, Heuner A, Silbernagl S (1990) pHi-dependent membrane conductance of proximal tubule cells in culture (OK): diffrential effects on K+- and Na+-conductive channels. J Membr Biol 117:243–251
Soltoff SP, Mandel LJ (1983) Amiloride directly inhibits the (Na++K+)-ATPase activity of rabbit kidney proximal tubules. Science 220:957–959
Spicer SS, Schulte BA, Adams JC (1990) Immunolocalization of Na+, K+-ATPase and carbonic anhydrase in the gerbil's vestibular system. Hear Res 43:205–218
Vergara C, Latorre R (1983) Kinetics of Ca2+-activated K+ channels from rabbit muscle incorporated into planar bilayers. Evidence for Ca2+ and Ba2+ blockade. J Gen Physiol 82:543–568
Völkl H, Lang F (1988) Effect of amiloride on cell volume regulation in renal straight proximal tubules. Biochim Biophys Acta 946:5–10
Wangemann P, Marcus DC (1989) Membrane properties of transitional cells of the Gerbil ampulla: K+ conductance, Na+/H+ exchanger, (Na++K+)-ATPase (abstract) FASEB J 3:A564
Wangemann P, Marcus DC (1989) Membrane potential measurements of transitional cells from the crista ampullaris of the gerbil-effects of barium, quinidine, quinine, tetraethylammonium, cesium, ammonium, thallium, and ouabain. Pflügers Arch 414:656–662
Wangemann P, Marcus DC (1992) The membrane potential of vestibular dark cells is controlled by a large Cl− conductance. Hear Res 62:149–156
Wangemann P, Wittner M, Di Stefano A, Englert HC, Lang HJ, Schlatter E, Greger R (1986) Cl−-channel blockers in the thick ascending limb of Henle-structure-activity relationship. Pflügers Arch (Suppl 2) 407:S128-S141
Wangemann P, Shiga N, Marcus DC (1993) pH-sensitivity of the membrane potential and cytosolic pH-regulation in transitional cells (abstract). Assoc Res Otolaryngol 16:107
Wangemann P, Shiga N, Marcus DC (1993) The Na+/H+ exchanger in transitional cells of the inner ear. Hear Res 69:107–114
Wangemann P, Shiga N, Marcus DC (1993) A pH-sensitive cation conductance observed in the presence of amiloride and barium but not under control conditions (abstract). 12. Congress of the International Union of Physiological Sciences (Glasgow)
Zweifach A, Desir GV, Aronson PS, Giebisch G (1992) Inhibition of Ca-activated K+ channels from renal microvillus membrane vesicles by amiloride analogs. J Membr Biol 128:115–122
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Wangemann, P., Shiga, N. Ba2+ and amiloride uncover or induce a pH-sensitive and a Na+ or non-selective cation conductance in transitional cells of the inner ear. Pflügers Arch. 426, 258–266 (1994). https://doi.org/10.1007/BF00374780
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DOI: https://doi.org/10.1007/BF00374780