title: Membrane potential measurements of transitional cells from the crista ampullaris of the gerbil. Effects of barium, quinidine, quinine, tetraethylammonium, cesium, ammonium, thallium and ouabain.
abstract: Transitional cells of the crista ampullaris were impaled with microelectrodes in order to record the membrane potential (PD) and to investigate membrane properties. In control solution the PD was -87 +/- 1 mV (n = 103). This value is not significantly different from -83 +/- 2 mV (n = 24) measured in Cl- free solution. [Cl-] steps from 150 to 15 mmol/l (n = 24) depolarized the membrane by about 2 mV, indicating a minor Cl- conductance. The transference number for K+ was 0.75 +/- 0.01 (n = 79) obtained from the PD responses to K+ steps from 3.6 to 25 mmol/l. The cell membrane depolarized and the amplitude of PD responses to [K+] steps was reduced by Ba2+ (2.10(-6) to 10(-3) mol/l), quinidine (10(-3) mol/l), quinine (10(-3) mol/l), Rb+ (20 mmol/l), Cs+ (20 mmol/l), NH4+ (20 mmol/l) and Tl+ (0.5 mmol/l), whereas tetraethylammonium (TEA, 20 mmol/l) had no effect. The dose-response curve for Ba2+ in the presence of 3.6 mmol/l K+ was shifted to the right by approximately three decades in the presence of 25 mmol/l K+ and by a factor of about 4 in the presence of 135 mmol/l gluconate as a substitute for Cl-. Transitional cells were depolarized by ouabain, suggesting the presence of (Na+ + K+)-ATPase.
authors: Boys Town National Institute, Omaha, NE 68131.
authors: P
authors: P
authors: Wangemann
authors: D C
authors: DC
authors: Marcus
mesh_terms: D000818:Animals; D002412:Cations / Q000494:pharmacology*; D002712:Chlorides / Q000494:pharmacology; D007758:Ear, Inner / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D004594:Electrophysiology; D005849:Gerbillinae; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D010042:Ouabain / Q000494:pharmacology; D011802:Quinidine / Q000494:pharmacology; D011803:Quinine / Q000494:pharmacology; D019789:Tetraethylammonium; D013757:Tetraethylammonium Compounds / Q000494:pharmacology
chemical_list: D002412:Cations; D002712:Chlorides; D013757:Tetraethylammonium Compounds; D010042:Ouabain; D019789:Tetraethylammonium; D011803:Quinine; D011802:Quinidine