At micromolar concentrations, acetyl-CoA inhibited hepatic carnitine acyltransferase activity and mitochondrial fatty acid oxidation. The inhibitory effects were not nearly as potent on a molar basis as those of malonyl-CoA; nevertheless, the cytosolic concentrations of acetyl-CoA, as yet unknown, may be sufficient (>30 μM) to curtail appreciably the mitochondrial transfer of long-chain acyl-CoA units and fatty acid oxidation. Hence acetyl-CoA may also partially regulate hepatic ketogenesis.
