Pore properties and pharmacological features of the P2X receptor channel in airway ciliated cells.

Airway ciliated cells express an ATP-gated P2X receptor channel of unknown subunit composition (P2X(cilia)) which is modulated by Na+ and by long exposures to ATP. P2X(cilia) was investigated by recording currents from freshly dissociated rabbit airway ciliated cells with the patch-clamp technique in the whole-cell configuration. During the initial continuous exposure to extracellular ATP, P2X(cilia) currents gradually increase in magnitude (priming), yet the permeability to N-methyl-D-glucamine (NMDG) does not change, indicating that priming does not arise from a progressive change in pore diameter.