High Dietary Fat Reduces the Rate of Pyruvate Supported Respiration in Isolated Cardiac Mitochondria.

<p>C57BL/6 mice were fed a control or high fat diet for 1 d to 20 wk. Cardiac mitochondria were then isolated and incubated at 0.25 mg/mL with 25 µM palmitoylcarnitine and 1.0 mM malate or 100 µM pyruvate and 1.0 mM malate as respiratory substrates. State 3 respiration was initiated by the addition of 0.25 mM ADP at 2.0 min. Representative oxygen consumption traces for mitochondria isolated from mice fed control or high fat diet for 20 wk using <b>A</b>. pyruvate or <b>D</b>. palmitoylcarnitine. <b>B</b>. Percentage decrease in the rate of pyruvate-supported ADP-dependent (state 3) respiration relative to controls for diet durations indicated (n = 5, 11, and 9 for 1 d, 1wk, and 20 wk). C. Mass spectrometric quantification of the protein levels of each PDH subunit (n = 5). All data are presented as the mean ± SEM with <i>p</i> values: * < 0.05; ** < 0.01; and *** < 0.001.