Hepatocytes deliver ketone bodies to the circulation because they lack which of the following enzymes?

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Hepatocytes lack succinyl-CoA: 3-oxoacid-CoA transferase, which is necessary for the utilization of ketone bodies. This enzyme is present in peripheral tissues, allowing them to use ketone bodies for energy.  Ketogenesis occurs in the liver from acetyl-CoA during high rates of fatty acid oxidation and during early starvation. The principal ketone bodies are acetoacetate and b-hydroxybutyrate, which are reversibly synthesized in a reaction catalyzed by b-hydroxybutyrate dehydrogenase. The liver delivers b-hydroxybutyrate to the circulation where it is taken up by nonhepatic tissue for use as an oxidizable fuel. The brain will derive much of its energy from ketone body oxidation during fasting and starvation. Within extrahepatic tissues, b-hydroxybutyrate is converted to acetoacetate byb-hydroxybutyrate dehydrogenase. Acetoacetate is reactivated to acetoacetyl-CoA in a reaction catalyzed by succinyl-CoA: 3-oxoacid-CoA-transferase (also called succinyl-CoA-acetoacetate-CoA-transferase or acetoacetate: succinyl-CoA-CoA transferase), which uses succinyl-CoA as the source of CoA. This enzyme is not present in hepatocytes. The acetoacetylCoA is then converted to 2 moles of acetyl-CoA by the thiolase reaction of fatty acid oxidation.

Hepatocytes Deliver Ketone Bodies to the Circulation Because They Lack