Figure 6.

Dual effects of Ca²⁺on mitochondrial respiration in intact cells.A, representative images of mito-GEM-GECO1 AML12 cells. AML12 cells were transfected with mito-GEM-GECO1 for the evaluation of intramitochondrial Ca²⁺ levels. Fluorescence was assessed by confocal microscopy under basal conditions, followed by addition of thapsigargin (TG, 2 μM) or adrenaline (ADR, 20 μM). The arrow indicates ADR/TG addition. B–I, O₂ consumption rates (OCRs) of AML12 cells were measured using a Seahorse Extracellular Flux Analyzer under basal conditions, followed by injection of DMSO (diluent), 20 μM ADR or 2 μM TG, oligomycin (oligo, 1 μM), CCCP (5 μM), and rotenone + antimycin (R/AA, 1 μM each). B and E, OCR traces. The insets represent the magnified area indicated by the dotted lines. C, ∗∗p = 0.0044 versus CT. C and F, quantification of basal respiration. F, ∗∗p = 0.0067 versus CT. D and G, quantification of maximal respiration. H, long traces of OCRs after TG injection. I, quantification of basal respiration of H. ∗∗p = 0.0021 versus CT. Results are expressed as means ± SEM of four independent experiments. Student’s t test.