Agonist-induced changes in intracellular Ca²⁺ levels in HEK293 cells expressing either <i>Am</i>DOP2 receptors or <i>Am</i>OA1 receptors.

<p>Cells were preloaded with the [Ca²⁺]_I reporter dye Fluo-4 and monitored for agonist-induced changes in fluorescence signal. The data shown are from a single trial and are representative of results obtained from 3 independent trials at each agonist concentration (with two internal replicates per trial), and over 30 trials using 1 µM. Changes in fluorescence examined in the following: (A) <i>Am</i>DOP2-expressing HEK293 cells exposed to 1 µM DA, OA or TA; (B) <i>Am</i>OA1-expressing HEK293 cells exposed to 1 µM DA, OA or TA; (C) <i>Am</i>DOP2-expressing HEK293 cells exposed to DA at the concentrations indicated to the right of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0026809#pone-0026809-g001" target="_blank">Figure 1C</a>; (D) <i>Am</i>OA1-expressing HEK293 cells exposed to OA at the concentrations indicated to the right of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0026809#pone-0026809-g001" target="_blank">Figure 1D</a>.