Figure 6:  Dynamic activation of human P2X1 receptors.

ATP (10 uM) was applied to 1321N1 human astrocytoma cells that were stably transfected with cDNA encoding the human P2X1 receptor.  Cell surface receptor activation was monitored through the use of the calcium-sensitive dye fluo-3.  Increases in intracellular fluorescence intensity reflect the opening of P2X1 receptor channels, influx of extracellular calcium, and subsequent calcium binding to fluo-3.  Under resting conditions, transient activation of these receptors mediates a net influx of cations into the cell, resulting in membrane depolarization.1321N1 were stably transfected with cDNA encoding the human P2X1 receptor.

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published 2000