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Voltage-dependent outward K(+) current in intermediate cell of stria vascularis of gerbil cochlea.
Am J Physiol. 1999 07; 277(1):C91-9.AJ

Abstract

A voltage-dependent outward K(+) (K(V)) current in the intermediate cell (melanocyte) of the cochlear stria vascularis was studied using the whole cell patch-clamp technique. The K(V) current had an activation threshold voltage of approximately -80 mV, and 50% activation was observed at -42.6 mV. The time courses of activation and inactivation were well fitted by two exponential functions: the time constants at 0 mV were 7.9 and 58.8 ms for activation and 0.6 and 4.3 s for inactivation. The half-maximal activation time was 13. 8 ms at 0 mV. Inactivation of the current was incomplete even after a prolonged depolarization of 10 s. This current was independent of intracellular Ca(2+). Quinine, verapamil, Ba(2+), and tetraethylammonium inhibited the current in a dose-dependent manner, but 4-aminopyridine was ineffective at 50 mM. We conclude that the K(V) conductance in the intermediate cell may stabilize the membrane potential, which is thought to be closely related to the endocochlear potential, and may provide an additional route for K(+) secretion into the intercellular space.

Authors+Show Affiliations

Department of Physiology, Kochi Medical School, Nankoku 783-8505, Japan. takeuchi@kochi-ms.ac.jpNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

10409112

Citation

Takeuchi, S, and M Ando. "Voltage-dependent Outward K(+) Current in Intermediate Cell of Stria Vascularis of Gerbil Cochlea." The American Journal of Physiology, vol. 277, no. 1, 1999, pp. C91-9.
Takeuchi S, Ando M. Voltage-dependent outward K(+) current in intermediate cell of stria vascularis of gerbil cochlea. Am J Physiol. 1999;277(1):C91-9.
Takeuchi, S., & Ando, M. (1999). Voltage-dependent outward K(+) current in intermediate cell of stria vascularis of gerbil cochlea. The American Journal of Physiology, 277(1), C91-9. https://doi.org/10.1152/ajpcell.1999.277.1.C91
Takeuchi S, Ando M. Voltage-dependent Outward K(+) Current in Intermediate Cell of Stria Vascularis of Gerbil Cochlea. Am J Physiol. 1999;277(1):C91-9. PubMed PMID: 10409112.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Voltage-dependent outward K(+) current in intermediate cell of stria vascularis of gerbil cochlea. AU - Takeuchi,S, AU - Ando,M, PY - 1999/7/17/pubmed PY - 1999/7/17/medline PY - 1999/7/17/entrez SP - C91 EP - 9 JF - The American journal of physiology JO - Am J Physiol VL - 277 IS - 1 N2 - A voltage-dependent outward K(+) (K(V)) current in the intermediate cell (melanocyte) of the cochlear stria vascularis was studied using the whole cell patch-clamp technique. The K(V) current had an activation threshold voltage of approximately -80 mV, and 50% activation was observed at -42.6 mV. The time courses of activation and inactivation were well fitted by two exponential functions: the time constants at 0 mV were 7.9 and 58.8 ms for activation and 0.6 and 4.3 s for inactivation. The half-maximal activation time was 13. 8 ms at 0 mV. Inactivation of the current was incomplete even after a prolonged depolarization of 10 s. This current was independent of intracellular Ca(2+). Quinine, verapamil, Ba(2+), and tetraethylammonium inhibited the current in a dose-dependent manner, but 4-aminopyridine was ineffective at 50 mM. We conclude that the K(V) conductance in the intermediate cell may stabilize the membrane potential, which is thought to be closely related to the endocochlear potential, and may provide an additional route for K(+) secretion into the intercellular space. SN - 0002-9513 UR - https://www.unboundmedicine.com/medline/citation/10409112/Voltage_dependent_outward_K_+__current_in_intermediate_cell_of_stria_vascularis_of_gerbil_cochlea_ L2 - https://journals.physiology.org/doi/10.1152/ajpcell.1999.277.1.C91?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -