Fig. 6.

Short-chain dicarboxylylcarnitines have little ¹³C labeling in the perfused hearts with [¹³C₆]glucose and [1-¹³C]palmitate. Rat hearts were perfused with 40% 11 mM [¹³C₆]glucose, [1-¹³C]palmitate, 0.1 mM 2-DG, 3% BSA, 100 µU insulin, and 50 µM l-carnitine (control, n = 5), control + 3 mM propionate (PA, n = 5), and PA + 3 mM l-carnitine (PA + Carn, n = 5). A–F: labeling of isotopologues of succinyl-CoA, MM-CoA, malonyl-CoA, succinylcarnitine, MM-carnitine, and malonylcarnitine. The error bar is the standard deviation of analysis. *P < 0.05, **P < 0.01, and ***P < 0.001. MM-, methylmalonyl; M0, M1, . . . , Mn means the isotopologues that contain n heavy atoms in a molecule.