High-conductance K+ channels in guinea pig gallbladder epithelium
Meyer, G.
Bollettino della Societa Italiana di Biologia Sperimentale 68(6): 373-378
1992
ISSN/ISBN: 0037-8771 PMID: 1485922 Document Number: 398589
Since secretion of electrolytes may be regulated by membrane potential difference, ion channels were studied using patchclamp technique. We have identified, in cell-attached configuration, inward-rectifying channels: the zero-current potential corresponded to the K+ equilibrium potential calculated from intracellular K+ activity. Using inside-out configuration and symmetric 145 mM KCl salines, i/V curve was linear, channel conductance was about 170 pS and the reversal potential 0 mV. The channels were selective for K+ over Na+, N-methylglucamine and anions and were activated by membrane depolarization.