title: Contribution of 3-hydroxyisobutyrate to the measurement of 3-hydroxybutyrate in human plasma: comparison of enzymatic and gas-liquid chromatography-mass spectrometry assays in normal and in diabetic subjects.
abstract: In this study we employed a capillary gas-liquid chromatographic-mass spectrometric (GLC-MS) method to measure the plasma concentrations of 3-hydroxybutyrate (3-OHB) and 3-hydroxyisobutyrate (3-OHIB) in overnight fasted diabetic subjects and in normal subjects. Plasma contents of 3-hydroxybutyrate measured in this fashion were identical to those obtained by enzymatic assay using a commercial preparation of beta-hydroxybutyrate dehydrogenase, indicating no significant contamination of this enzyme preparation with 3-hydroxyisobutyrate dehydrogenase. In normal individuals, plasma 3-OHIB concentration was 21 +/- 2 microM in the overnight fasted state and was higher in diabetic subjects (38 +/- 5 microM) and in subjects fasted for 72 h (97 +/- 4 microM). In the postabsorptive state, 3-OHIB was 33% the concentration of 3-OHB in normals and 17% that of 3-OHB in the diabetics.
authors.affiliation: Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110.
authors.forename: A
authors.initials: A
authors.lastname: Avogaro
authors.forename: D M
authors.initials: DM
authors.lastname: Bier
mesh_terms: D020155:3-Hydroxybutyric Acid; D000328:Adult; D003920:Diabetes Mellitus / Q000097:blood*; D005189:False Positive Reactions; D005215:Fasting; D005470:Fluorometry; D005502:Food; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D006884:Hydroxybutyrate Dehydrogenase; D006885:Hydroxybutyrates / Q000097:blood*; D011786:Quality Control
chemical_list: D006885:Hydroxybutyrates; D006884:Hydroxybutyrate Dehydrogenase; C020757:3-hydroxyisobutyric acid; D020155:3-Hydroxybutyric Acid