BACKGROUND: Machine perfusion with oxygenated preservation solution can support donor heart metabolism but the preservation solution should contain an oxidizable substrate to improve cellular energetics. We hypothesized that myocardial metabolism can be influenced by exogenous substrates in the preservation solution. METHODS: Eight groups of isolated @entity35 hearts (n = 4/group) were perfused with University of Wisconsin Machine Perfusion Solution containing @entity505 13 ( @entity7352 ) labeled @entity413 (2.5 mM, 5 mM, 10 mM, or 20 mM) or @entity2388 (5 mM, 10 mM, 20 mM, or 40 mM). Hearts were perfused at 0.5 mL/min for 6 h at 8  C, and myocardial @entity26 consumption (MVO(2)) was measured. At end-perfusion, magnetic resonance spectroscopy was performed on ventricular extracts to determine the contribution of exogenous, labeled substrate to glycolysis and oxidative metabolism by @entity7352 incorporation into metabolic intermediates. RESULTS: MVO(2) and perfusion conditions did not differ amongst groups. Exogenous @entity413 was metabolized by anaerobic glycolysis and contributed little to oxidative metabolism as measured by @entity7352 incorporation into metabolic intermediates. @entity2388 led to greater @entity880 enrichment via the @entity880 dehydrogenase reaction. Enrichment of @entity6626 ( @entity2974 ) cycle intermediates was also greater in all @entity2388 groups compared with @entity413 -containing groups (P < 0.05). Anaplerosis was increased in all @entity2388 groups (P < 0.05). CONCLUSIONS: The preservation solution substrate composition influences myocardial substrate metabolism during machine perfusion preservation of donor hearts. Exogenous @entity413 is a minor substrate in machine perfused myocardium, is primarily metabolized by glycolysis and does not contribute appreciably to oxidative metabolism. @entity2388 appears more effective in supporting myocardial metabolism. Further experiments examining the influences of substrate modifications on reperfusion function are warranted.

XXXX is an ineffective substrate for preservation of machine perfused donor hearts.

@entity26 :: ('MESH:D010100', 'Chemical') :: ['oxygen'] @entity7352 :: ('CHEBI:36928', 'Chemical') :: ['(13)C'] @entity2974 :: ('CHEBI:30956', 'Chemical') :: ['TCA'] @entity505 :: ('MESH:D002244', 'Chemical') :: ['carbon'] @entity6626 :: ('CHEBI:27093', 'Chemical') :: ['tricarboxylic acid'] @entity880 :: ('MESH:D019344', 'Chemical') :: ['lactate'] @entity35 :: ('10116', 'Species') :: ['rat'] @entity413 :: ('MESH:D005947', 'Chemical') :: ['glucose'] @entity2388 :: ('MESH:D019289', 'Chemical') :: ['Pyruvate', 'pyruvate']
@entity413 :: (MESH:D005947,Chemical) :: ['Glucose']
