(A–C) Real-time PCR results showing the increasing of UPR genes Grp78 (A), Atf4 (B) and Atf6 (C) in cardiomyocytes treated by cadmium (1 or 100 μM for 4–12 h). (D and E) Western blots and histograms showing the increasing of GRP78/BiP and p-eIF2α protein levels in cardiomyocytes treated by cadmium (1 or 100 μM for 4–12 h). Results are averages of three independent experiments. Data represent mean ± S.E.M. **P<0.01 and ***P<0.001.