[High-conductance K+ channels in guinea pig gallbladder epithelium].
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.
Meyer
G
G
Dipartimento di Fisiologia e Biochimica Generali, Università degli Studi di Milano.
D000818:Animals; D004847:Epithelial Cells; D004848:Epithelium / Q000502:physiology; D005704:Gallbladder / Q000502:physiology*; D006168:Guinea Pigs; D015640:Ion Channel Gating; D008564:Membrane Potentials; D015221:Potassium Channels / Q000502:physiology*
D015221:Potassium Channels
Canali del K+ a elevata conduttanza in epitelio di cistifellea di cavia.