Figure 2.

Effect of NPS 2143 on the concentration-response curve of the mutant Gln723 CaSR in transfected HEK293 cells. HEK293 cells were transiently transfected with wild-type or the mutant CaSR-EGFP construct. Single, live cells were loaded with indo-1-acetoxymethylester, which emits fluorescence at 525 nm. NPS 2143 was added at 0nM, 20nM, 40nM, and 80nM concentrations to HEK293 cells transfected with the mutant Gln723 CaSR-EGFP. Cells transfected with the CaSR were selected by fluorescence-activated cell sorting, and the Ca²⁺_o-evoked increases in Ca²⁺_i concentrations were measured. The concentration-response curves of the untreated (dashed line) and NPS 2143-treated (dotted lines) mutant Gln723 receptor were compared with the untreated wild-type (WT) Leu723 CaSR-EGFP (solid line). The increments in Ca²⁺_o concentrations from 0mM to 10mM are shown on the x-axis, and the Ca²⁺_i response, which was measured as a percentage of the maximum normalized response, is shown on the y axis (mean ± SEM of 4 estimations).