Hepatic utilization of exogenous nucleotide precursors for restoration of ATP after cold ischemia in rats

The study objective was to assess hepatic utilization of exogenous adenosine or adenine to enhance ATP recovery in rat liver after cold ischemia. ATP was measured noninvasively by ³¹P nuclear magnetic resonance (NMR) in perfused livers before and after 18 h of cold ischemia. The hepatocellular concentration of ATP during the initial postischemic reperfusion without adenosine or adenine coinfusion was 60% of that in fresh liver. The ATP increased significantly (P < 0.001) to 139% and 82% of baseline in postischemic livers coinfused for 90 min with adenosine or adenine (final concentration, 1 mmol/L), respectively. Less than 0.5% of the excess adenosine was catabolized to uric acid. In conclusion, adenosine and, to a lesser extent, adenine are salvaged by liver after extended cold ischemia to enhance ATP restoration. Provision of these ATP precursors, as components of an enterai formulation may facilitate the repletion of liver ATP and foster early resumption of liver function after an ischemic insult.