HIF-1α upregulation (A) and nuclear translocation (B) upon stimulation with hypoxia-mimetic agent cobalt chloride and the effect of remifentanil preconditioning in HCM cells. (A) Western blot analysis of the levels of HIF-1α. Data were normalized to β-actin. (B) Immunofluorescence analysis of cellular localization of HIF-1α (red). Representative microphotographs are shown, objective 10×, scale bars 10 μm. F-actin staining (green) and nucleus staining (blue) were also considered. Nuclear immuno-signals of HIF-1α were calculated [%]. Bars indicate SD, n = 3, ***p < 0.001 compared to normoxic control (CTR), ###p < 0.001 compared to hypoxic control (CTR) (ANOVA and Dunnett's a posteriori test). CTR, control; R, remifentanil preconditioning.