U46619 does not induce hypertrophy or increase protein synthesis. A. Flow cytometry forward-scatter (FSC-H) data was performed on more than 10,000 live gated cells/sample (n = 3). HL-1 cardiomyocytes were treated for 48 h with vehicle, increasing concentrations of U46619 (0.1-10 μM) [T(X) <4; p > 0.01], or a positive control, FGF23 (35 pM) [T(X) = 61, p < 0.01]. Results from independent experiments were normalized to vehicle controls and averaged and show that U46619 did not increase cell size (p > 0.05) while FGF23 increased cell size compared to vehicle (p < 0.05). B. Total protein concentration of ventricular muscle strips did not increase following 48 h treatment with U46619 (0.1-10 μM; n = 8; p > 0.05), but did increase after treatment with FGF23 (35 pM; n = 5; p < 0.05). *Statistical difference from vehicle.