FIGURE 2.

Mitochondrial proteins are hyperacetylated in the hearts of diabetic mice and hypoacetylated in PPARα^−/− knock-out mice. The levels of acetylation are a predictor of whether pyruvate or palmitoylcarnitine produces maximal state 3 respiratory rates. A, mitochondria were analyzed by Western blotting (WB) using an acetylated lysine (AcK) antibody. An antibody against lipoic acid (LA) bound to the E2 subunit of PDH was used as a loading control (32) as its levels did not significantly differ between experimental groups. The samples shown are from a single blot and the same exposure. The image was subsequently cropped for clarity of presentation. B, acetylation densitometry was determined on the entire lane of Akita (n = 7), STZ (n = 5), and PPARα^−/− (n = 6) mitochondria and expressed relative to the appropriate age-matched control. C, state 3 respiration rates were determined with either PC and malate or pyruvate and malate for wild type (n = 4), Akita (n = 5), and PPARα^−/− (n = 4) heart mitochondria. The lines connect measurements from the same preparation of mitochondria. D, the ratio of PC-supported state 3 to pyruvate (Pyr)-supported state 3 rates was quantified. Experimental points are from unique mitochondrial preparations, and error bars are the standard deviation. *, p < 0.05, paired Student's t test.