The <i>Lym</i>P2X gene encodes an ATP gated ion channel.

<p>Membrane currents were recorded by two-electrode voltage clamp in <i>Xenopus</i> oocytes expressing <i>Lym</i>P2X receptors. (A) Example sequential current traces in response to a 2 second application (solid black bar) of 100 µM ATP showed a marked run down in peak current amplitude with a 5 minute recovery period between applications. (B) Sequential application of ATP (100 µM for 2 seconds) with a 15 minute recovery period between applications showed no rundown in amplitude after the second ATP application (n = 5). (C) A 5 minute recovery period between sequential application of 10 µM ATP (black bars) resulted in reproducible responses after two initial applications of 100 µM ATP.