Significance of blood ketone body ratio as an indicator of hepatic cellular energy status in jaundiced rabbits.

Changes in the free NAD+/NADH ratio and the energy charge (ATP + 1/2 ADP/ATP + ADP + AMP) of the liver were compared with the ratio of acetoacetate to beta-hydroxybutyrate of arterial blood in rabbits subjected to ligation of the common bile duct. Both the acetoacetate/beta-hydroxybutyrate ratio of the liver, which reflects mitochondrial free NAD+/NADH ratio, and the heptic energy charge decreased in accordance with the decrease of mitochondrial phosphorylative activity after the ligation. The decrease in the acetoacetate/beta-hydroxybutyrate ratio of the liver was attributed to a restricted mitochondrial reoxidation of NADH due to an inhibition of oxidative phosphorylation. Moreover, changes in the ratio of acetoacetate to beta-hydroxybutyrate in arterial blood were positively correlated with those of the liver (r = 0.695, P less than 0.01) and the hepatic energy charge (r = 0.844, P less than 0.01). It is suggested that the ratio of acetoacetate to beta-hydroxybutyrate in blood can reflect the energy charge of the liver in jaundiced rabbits.