title: Glucose production, gluconeogenesis, and hepatic tricarboxylic acid cycle fluxes measured by nuclear magnetic resonance analysis of a single glucose derivative.
abstract: A triple-tracer method was developed to provide absolute fluxes contributing to endogenous glucose production and hepatic tricarboxylic acid (TCA) cycle fluxes in 24-h-fasted rats by (2)H and (13)C nuclear magnetic resonance (NMR) analysis of a single glucose derivative. A primed, intravenous [3,4-(13)C(2)]glucose infusion was used to measure endogenous glucose production; intraperitoneal (2)H(2)O (to enrich total body water) was used to quantify sources of glucose (TCA cycle, glycerol, and glycogen), and intraperitoneal [U-(13)C(3)] propionate was used to quantify hepatic anaplerosis, pyruvate cycling, and TCA cycle flux. Plasma glucose was converted to monoacetone glucose (MAG), and a single (2)H and (13)C NMR spectrum of MAG provided the following metabolic data (all in units of micromol/kg/min; n = 6): endogenous glucose production (40.4+/-2.9), gluconeogenesis from glycerol (11.5+/-3.5), gluconeogenesis from the TCA cycle (67.3+/-5.6), glycogenolysis (1.0+/-0.8), pyruvate cycling (154.4+/-43.4), PEPCK flux (221.7+/-47.6), and TCA cycle flux (49.1+/-16.8). In a separate group of rats, glucose production was not different in the absence of (2)H(2)O and [U-(13)C]propionate, demonstrating that these tracers do not alter the measurement of glucose turnover.
authors.affiliation: The Mary Nell and Ralph B. Rogers Magnetic Resonance Center, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA.
authors.forename: Eunsook S
authors.initials: ES
authors.lastname: Jin
authors.forename: John G
authors.initials: JG
authors.lastname: Jones
authors.forename: Matthew
authors.initials: M
authors.lastname: Merritt
authors.forename: Shawn C
authors.initials: SC
authors.lastname: Burgess
authors.forename: Craig R
authors.initials: CR
authors.lastname: Malloy
authors.forename: A Dean
authors.initials: AD
authors.lastname: Sherry
mesh_terms: D000097:Acetonitriles / Q000493:pharmacokinetics; D000818:Animals; D001786:Blood Glucose / Q000032:analysis / Q000378:metabolism; D002250:Carbon Radioisotopes; D002952:Citric Acid Cycle / Q000502:physiology*; D005215:Fasting; D005943:Gluconeogenesis / Q000502:physiology*; D005947:Glucose / Q000031:analogs & derivatives* / Q000032:analysis / Q000096:biosynthesis* / Q000737:chemistry*; D008099:Liver / Q000378:metabolism*; D008297:Male; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011849:Radioactive Tracers; D051381:Rats; D017207:Rats, Sprague-Dawley; D014530:Uridine Diphosphate / Q000493:pharmacokinetics
chemical_list: D000097:Acetonitriles; D001786:Blood Glucose; D002250:Carbon Radioisotopes; D011849:Radioactive Tracers; C028223:1,2-O-isopropylidene-D-glucofuranose; D014530:Uridine Diphosphate; D005947:Glucose; C032159:acetonitrile