Referenced in: none

Automatically associated channels: Kir2.1

Title: Characterization of inwardly rectifying K(+) conductance across the basolateral membrane of rat tracheal epithelia.

Authors: J S Jeong, H J Lee, J S Jung, S H Shin, Y J Son, J H Yoon, S H Lee, H S Lee, I Yun, T H Hwang

Journal, date & volume: Biochem. Biophys. Res. Commun., 2001 Nov 9 , 288, 914-20

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/11688996

Abstract
The rat primary cultured-airway monolayer has been an excellent model for deciphering the ion channel after nystatin permeabilization of its basolateral or apical membrane. Inwardly rectifying K(+) currents were characterized across the basolateral membrane in symmetrical HCO(-)(3)-free high K(+) Ringer's solution (125 mM) in this study. The potency of K(+) channel inhibitors against K(+) conductance was Ba(2+) (IC(50) = 5 microM) > Cs(+) (IC(50) = 2 mM) >> glybenclamide (IC(50) > 5 mM) >> TEA (IC(50) >> 100 mM). The application of basolateral Cs(+) changed K(+) conductance into an oscillating current, and its frequency (holding voltage = -100 mV) increased with increase in concentration of basolateral Cs(+) (0.05-5 mM) and in degree of hyperpolarization. Addition of basolateral Cs(+) blocked inward current strongly at -100 mV and hardly at all at -60 mV, giving a sharp curvature to the I-V relation of the IRK current. RT-PCR, Western blotting, and immunohistochemical analyses showed that Kir2.1 might be present in basolateral membrane of tracheal epithelia and plasma membrane of pulmonary alveolar cells.