Figure 5. Mcu is necessary for β-adrenergic increases in mitochondrial energetics.

ACMs were isolated from Mcu^fl/fl and Mcu^fl/fl x αMHC-MCM hearts 1wk post tamoxifen treatment. A) ACMs were monitored spectrofluorometrically for changes in NADH autoflourescence after treatment with isoproterenol (Iso, 10-μM) followed by the addition of rotenone (Rot, 2-μM). Mean NADH recording from 3 independent experiments. B) Baseline NADH levels calculated as fluorescent intensity. C) Percent change in NADH levels following Iso treatment, corrected to Mcu^fl/fl ACMs. D) NADH fluorescent intensity after treatment with rotenone. Calculated as percent change from baseline to post-rotenone corrected to control ACMs. E) Isolated ACMs were assayed for mitochondrial OxPhos function using a Seahorse Bioanalyzer to measure oxygen consumption rates (OCR). Baseline OCR. F) ACMs were treated with either vehicle (Veh) or isoproterenol (Iso, 10-μM) and FCCP was injected to augment maximal OCR. (All data shown as mean +/− SEM, *p<0.05, ***p<0.001 vs. Mcu^{fl/fl; ##}p<0.01, ^###p<0.001 vs. Veh)