A problem associated with the measurement of ketone body kinetics in vivo

Abstract

[3–14C]acetoacetate (AcAc) and [2–14C]acetate were infused in separate experiments into nine paired rats. The specific activity (SA) ratio SAβOHB/SAAcAc was 0.23 ± 0.02 when [3–14C]AcAc was the tracer and 0.78 ± 0.1 when [2–14C]acetate was infused. These experiments demonstrate the inadequacy of the common practice of using only one labelled ketone body to calculate the turnover rate of both AcAc and β-hydroxybutyrate (βOHB) simultaneously.