Lung preservation solution substrate composition affects rat lung oxidative metabolism during hypothermic storage

Lungs harvested for transplantation utilize oxygen after procurement. We investigated the effects of storage solution substrate composition on pulmonary oxidative metabolism and energetics during the preservation interval. Rat lungs were harvested and stored at 10 °C in low-potassium dextran (LPD) solution. Groups of lungs were preserved with preservation solution containing 5 mM carbon-13 (13C) labeled glucose or increasing concentrations of 13C labeled pyruvate. Additional groups of rat lungs were studied with dichloroacetate (DCA) added to the pyruvate-modified preservation solutions. Oxidative metabolism (measured by 13C-enrichment of glutamate) and adenine nucleotide levels were quantified. Increasing preservation solution pyruvate concentration augmented glutamate 13C-enrichment up to a concentration of 32 mM pyruvate. DCA further stimulated oxidative metabolism only at lower concentrations of pyruvate (4 and 8 mM). ATP and ADP were not different among groups, but AMP levels were higher in the glucose group. These data suggest that altering the substrate composition of the preservation solution influences lung metabolism during allograft preservation for transplantation.