title: Noninvasive measurement of murine hepatic acetyl-CoA ¹³C-enrichment following overnight feeding with ¹³C-enriched fructose and glucose.
abstract: The (13)C-isotopomer enrichment of hepatic cytosolic acetyl-CoA of overnight-fed mice whose drinking water was supplemented with [U-(13)C]fructose, and [1-(13)C]glucose and p-amino benzoic acid (PABA) was quantified by (13)C NMR analysis of urinary N-acetyl-PABA. Four mice were given normal chow plus drinking water supplemented with 5% [1-(13)C]glucose, 2.5% [U-(13)C]fructose, and 2.5% fructose (Solution 1) overnight. Four were given chow and water containing 17.5% [1-(13)C]glucose, 8.75% [U-(13)C]fructose and 8.75% fructose (Solution 2). PABA (0.25%) was present in both studies. Urinary N-acetyl-PABA was analyzed by (13)C NMR. In addition to [2-(13)C]- and [1,2-(13)C]acetyl isotopomers from catabolism of [U-(13)C]fructose and [1-(13)C]glucose to acetyl-CoA, [1-(13)C]acetyl was also found indicating pyruvate recycling activity. This precluded precise estimates of [1-(13)C]glucose contribution to acetyl-CoA while that of [U-(13)C]fructose was unaffected. The fructose contribution to acetyl-CoA from Solutions 1 and 2 was 4.0 ± 0.4% and 10.6 ± 0.6%, respectively, indicating that it contributed to a minor fraction of lipogenic acetyl-CoA under these conditions.
authors.affiliation: Center for Neurosciences and Cell Biology, Department of Zoology, University of Coimbra, Coimbra 3004-517, Portugal.
authors.forename: Filipa
authors.initials: F
authors.lastname: Carvalho
authors.forename: Joao
authors.initials: J
authors.lastname: Duarte
authors.forename: Ana Rita
authors.initials: AR
authors.lastname: Simoes
authors.forename: Pedro F
authors.initials: PF
authors.lastname: Cruz
authors.forename: John G
authors.initials: JG
authors.lastname: Jones
mesh_terms: D000105:Acetyl Coenzyme A / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002250:Carbon Radioisotopes / Q000737:chemistry; D003600:Cytosol / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D005632:Fructose / Q000008:administration & dosage / Q000378:metabolism*; D005947:Glucose / Q000008:administration & dosage / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D051379:Mice
chemical_list: D001786:Blood Glucose; D002250:Carbon Radioisotopes; D005227:Fatty Acids; D005632:Fructose; D000105:Acetyl Coenzyme A; D005947:Glucose