title: Characterizing lung metabolism with carbon-13 magnetic resonance spectroscopy in a small-animal model: evidence of gluconeogenesis during hypothermic storage.
abstract: Experimental evidence suggests storing lungs inflated with oxygen and with oxidizable substrate improves results of lung transplantation. Glucose is included in the low-potassium-dextran (LPD) solution Perfadex to achieve this goal. The authors hypothesized that other substrates might be more effective. Rat lungs were stored for 6 or 24 hr in LPD solution with the following carbon-13--labeled substrates: 5 mM glucose (Perfadex group), 32 mM pyruvate (pyruvate group), or both (combination group). Metabolism was assessed by magnetic resonance spectroscopy. Small amounts of exogenous glucose were oxidized in the Perfadex group. In contrast, exogenous pyruvate was the major substrate oxidized in the pyruvate and combination groups (P<0.01 vs. Perfadex). Carbon-13--labeled glucose and glycogen were detected in the pyruvate group, suggesting that gluconeogenesis and glycogen synthesis occur in glucose-deprived lungs. Lungs for transplantation metabolize substrates through both anabolic and catabolic pathways. These reactions may be important in designing improved solutions for lung preservation.
authors.affiliation: Department of Cardiovascular and Thoracic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Matthias
authors.initials: M
authors.lastname: Peltz
authors.forename: Tian-Teng
authors.initials: TT
authors.lastname: He
authors.forename: Glenn A
authors.initials: GA
authors.lastname: Adams
authors.forename: Robert Y
authors.initials: RY
authors.lastname: Chao
authors.forename: Dan M
authors.initials: DM
authors.lastname: Meyer
authors.forename: Michael E
authors.initials: ME
authors.lastname: Jessen
mesh_terms: D000818:Animals; D002247:Carbon Isotopes / Q000378:metabolism*; D003911:Dextrans / Q000494:pharmacology; D004195:Disease Models, Animal; D005943:Gluconeogenesis; D005947:Glucose / Q000378:metabolism; D006003:Glycogen / Q000737:chemistry; D007036:Hypothermia, Induced; D008168:Lung / Q000378:metabolism* / Q000473:pathology; D016040:Lung Transplantation / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D023421:Models, Animal; D009926:Organ Preservation / Q000379:methods*; D019188:Organ Preservation Solutions / Q000494:pharmacology; D010100:Oxygen / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology; D011773:Pyruvates / Q000378:metabolism; D019289:Pyruvic Acid / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D002247:Carbon Isotopes; D003911:Dextrans; D019188:Organ Preservation Solutions; D011773:Pyruvates; D019289:Pyruvic Acid; D006003:Glycogen; D005947:Glucose; D011188:Potassium; D010100:Oxygen