Single cell calcium signal and fluorescence intensity of the stable EP
HEK293 cells. (I. & III.) Photomicrographs of stable EP1 HEK293 cells showing baseline calcium signal (a, c, and e), and then the calcium signal produced following the addition of 1 nM PGE1 (I.-b) or PGE2 (III.-b), 100 pM PGE1 (I.-d) or PGE2 (III.-d), and wash buffer (I.-F and III.-f). The calcium signal is also shown for the untransfected HEK293 cells alone (I-g. and III.-g) and with 1 nM PGE1 (I.-h) or PGE2 (III.-h). (II. & IV.) Fluorescence intensity of the stable EP1 HEK293 cells. The stable EP1 HEK293 cells were grown in glass-bottom plates and incubated with Fluo8-AM dye, followed by the addition of 1 nM (black upright triangles) PGE1 (II.) or PGE2 (IV.), 100 pM (black squares) PGE1 (II.) or PGE2 (IV.), or wash buffer (II. and IV., black inverted triangles), and the calcium signals were evaluated using the Nikon Ti-S eclipse microscope and plotted as fluorescence intensity. Also shown is the fluorescence intensity of the pcDNA3.1 vector-transfected HEK293 control cells (II. and IV., black circles) and the untransfected HEK293 control cells in the presence of 1 nM (black diamonds) PGE1 (II.) or PGE2 (IV.).