Ketone body enzyme activities in purified neurons, astrocytes and oligodendroglia

Ketone bodies serve as sources for energy and as precursors for lipid synthesis in developing brain. Whether neurons and neuroglia are equally capable of using ketone bodies during differentiation is not known. Using purified populations of neurons and astrocytes from developing rat brain and purified oligodendroglia from bovine brain, the activities for the three enzymes involved in ketone body metabolism were evaluated. Enzymatic activities were found in all three cell types. Surprisingly, astrocytes had the highest levels of activity for both 3-ketoacid-CoA transferase and acetoacetyl-CoA thiolase; these activites showed dramatic changes during development. Nonetheless, neurons, astrocytes and oligodendroglia are all quite capable of using ketone bodies as metabolic fuels.