Does an Inward-Rectifying K Channel Regulate Type-I Cell Response to Hypoxia?
Type-I cells (from rabbit embryos) in primary cell culture were studied using the patch-clamp technique on the cell-attached configuration. Cells exhibited resting potentials of about -40 mV under normoxia. In mot cases (76%), they were gradually depolarized to 0 mV by hypoxia (PO2: 3.7 kPa). Since the input resistance of type-I cells was large (about 4 gigohm) at their resting potential, small conductance changes at this level were expected to cause such a depolarizing effect. Indeed, a single K+ channel could be recorded, which was active at -50 mV with a conductance of 137 pS and inward rectification. Its open-probability was reversibly decreased during hypoxia.
KeywordsCarotid Body Taste Cell Single Channel Current Single Channel Recording Taste Receptor Cell
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