Epithelial Na channels: the nature of the conducting pore.
Na-selective, amiloride-sensitive ion channels are a crucial component of the system for controlled NaCl reabsorption across tight epithelia. A kinetic model for the process of Na conduction through the channel is presented. The model is based on a view of the possible geometry of the pore obtained from an analysis of voltage-dependent block of Na currents by impermeant cations. It is also consistent with the known electrophysiological properties of the channel, including single-channel currents, current-voltage relationships and saturation. The model, while not a unique explanation of the available data, may serve as a starting point for more detailed experimental and theoretical studies.
Department of Physiology, Cornell University Medical College, New York, N.Y.
L G
LG
Palmer
D000818:Animals; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D015222:Sodium Channels / Q000378:metabolism*
D015222:Sodium Channels