ORIGIN OF KETONE BODIES FROM FATS AND THEIR REGULATION

Abstract

Of the three substances usually grouped under the term "ketone bodies," namely, acetoacetic acid, betahydroxybutyric acid and acetone, the second is not a ketone, and the third represents merely a breakdown product of its more physiologically significant precursors. It is now generally agreed that under conditions leading to ketosis acetoacetic acid is the first ketone body to be formed.¹ It is known that various tissues of the mammalian organism are able to reduce acetoacetic acid to betahydroxybutyric acid and also to effect the reverse reaction. The direction of this reversible reaction depends on the concentration of substrates present and on the oxygen tension, and there is evidence that an equilibrium between these two substances is established rapidly.² It is, therefore, a matter of practical importance in balance or recovery experiments to estimate the amounts of both of these substances present in the tissues when attempting to account for