Fig. 10.
Fluorometric measurement of intracellular calcium in HEK293 coexpressing IP/TPα receptors (IP/TPα-HEK). A: representative fluorescence signals induced by increasing concentrations of U46619. B: average fluorescence increases induced by U46619. U46619 did not increase fluorescence in HEK293 cells not overexpressing IP/TP receptors. C: effect of U46619 (100 nM, black bar; 10 nM, gray bar) on calcium associated fluorescence in the presence of SQ29548 (10 nM to 1 μM) (D), U46619 (10 nM)-induced fluorescence in the presence of 12(S)-HETE (black bar) or 12(R)-HETE (white bar). Percent maximum is the fluorescence signal stimulated by test compound compared with vehicle control as 100%. In A, B, and D, fluorescence was normalized to total protein (fluorescence units/μg). Each value represents the mean ± SE; n = 4–8. *P < 0.05 compared with vehicle control.