Rates of catabolism calculated from 14CO2 production: artifacts and realities.

We present evidence that the metabolism of acetate and ethanol by the liver markedly decreases the yield of label from mitochondrial [14C]acetyl-CoA to 14CO2. The production of [14C]acetyl-CoA from a [14C]labeled substrate can be calculated from the production of 14CO2 if one assesses (1) 14CO2 reincorporation and (2) the yield of label from [14C]acetyl-CoA to CO2.