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Daurio NA, Wang Y, Chen Y, Zhou H, Carballo-Jane E, Mane J, Rodriguez CG, Zafian P, Houghton A, Addona G, McLaren DG, Zhang R, Shyong BJ, Bateman K, Downes DP, Webb M, Kelley DE, Previs SF. Spatial and temporal studies of metabolic activity: contrasting biochemical kinetics in tissues and pathways during fasted and fed states. Am J Physiol Endocrinol Metab 2019; 316:E1105-E1117. [PMID: 30912961 DOI: 10.1152/ajpendo.00459.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The regulation of nutrient homeostasis, i.e., the ability to transition between fasted and fed states, is fundamental in maintaining health. Since food is typically consumed over limited (anabolic) periods, dietary components must be processed and stored to counterbalance the catabolic stress that occurs between meals. Herein, we contrast tissue- and pathway-specific metabolic activity in fasted and fed states. We demonstrate that knowledge of biochemical kinetics that is obtained from opposite ends of the energetic spectrum can allow mechanism-based differentiation of healthy and disease phenotypes. Rat models of type 1 and type 2 diabetes serve as case studies for probing spatial and temporal patterns of metabolic activity via [2H]water labeling. Experimental designs that capture integrative whole body metabolism, including meal-induced substrate partitioning, can support an array of research surrounding metabolic disease; the relative simplicity of the approach that is discussed here should enable routine applications in preclinical models.
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Affiliation(s)
- Natalie A Daurio
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Yichen Wang
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Ying Chen
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Haihong Zhou
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Ester Carballo-Jane
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Joel Mane
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Carlos G Rodriguez
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Peter Zafian
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Andrea Houghton
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - George Addona
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - David G McLaren
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Rena Zhang
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Bao Jen Shyong
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Kevin Bateman
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Daniel P Downes
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Maria Webb
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - David E Kelley
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
| | - Stephen F Previs
- Merck Research Laboratories, Merck & Company, Incorporated, Kenilworth, New Jersey
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Jarak I, Barosa C, Martins FO, Silva JCP, Santos C, Belew GD, Rito J, Viegas I, Teixeira J, Oliveira PJ, Jones JG. Sources of hepatic glycogen synthesis in mice fed with glucose or fructose as the sole dietary carbohydrate. Magn Reson Med 2018; 81:639-644. [PMID: 30058123 DOI: 10.1002/mrm.27378] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/16/2018] [Accepted: 05/05/2018] [Indexed: 11/07/2022]
Abstract
PURPOSE The positional analysis of hepatic glycogen enrichment from deuterated water (2 H2 O) by 2 H NMR has been applied previously to resolve the contributions of glucose and fructose to glycogen synthesis in rodents fed a high sucrose diet. To further validate this method, this analysis was applied to mice fed with synthetic diets whose carbohydrate components consisted solely of either glucose or fructose. METHODS Eight glucose-fed and 12 fructose-fed mice were given 2 H2 O followed by ad libitum feeding overnight. Mice were then euthanized, hepatic glycogen was isolated and derivatized to monoacetone glucose, and 2 H-enrichment of positions 2, 5, and 6S were measured by 2 H NMR. From these data, the fraction of overnight glycogen appearance from the direct pathway and/or glycogen cycling and indirect pathway were estimated. Indirect pathway fractions were resolved into Krebs cycle and triose-phosphate sources-the latter including contributions from fructose metabolism. RESULTS After overnight feeding, the fraction of overnight glycogen appearance derived from direct pathway and/or glycogen cycling in glucose-fed-mice was 63 ± 1%. For the indirect pathway, Krebs cycle and triose-phosphate sources contributed 22 ± 1% and 15 ± 1%, respectively. For fructose-fed-mice, glycogen appearance was dominated by triose-phosphate sources (60 ± 2%) with lesser contributions from Krebs cycle (14 ± 1%) and direct and/or glycogen cycling (26 ± 2%). CONCLUSIONS 2 H NMR analysis of hepatic glycogen 2 H enrichment from 2 H2 O provides realistic profiles of dietary glucose and fructose contributions to hepatic glycogen synthesis in mice fed with diets containing 1 or the other sugar as the sole carbohydrate source.
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Affiliation(s)
- Ivana Jarak
- Center for Functional Ecology, Department of Life Sciences, University of Coimbra, Portugal
| | - Cristina Barosa
- Center for Neurosciences and Cell Biology, UC-Biotech, University of Coimbra, Portugal
| | - Fatima O Martins
- Center for Neurosciences and Cell Biology, UC-Biotech, University of Coimbra, Portugal
| | - Joao C P Silva
- Center for Neurosciences and Cell Biology, UC-Biotech, University of Coimbra, Portugal
| | - Cristiano Santos
- Center for Neurosciences and Cell Biology, UC-Biotech, University of Coimbra, Portugal
| | - Getachew Debas Belew
- Center for Neurosciences and Cell Biology, UC-Biotech, University of Coimbra, Portugal
| | - Joao Rito
- Center for Neurosciences and Cell Biology, UC-Biotech, University of Coimbra, Portugal
| | - Ivan Viegas
- Center for Functional Ecology, Department of Life Sciences, University of Coimbra, Portugal.,Center for Neurosciences and Cell Biology, UC-Biotech, University of Coimbra, Portugal
| | - Jose Teixeira
- Center for Neurosciences and Cell Biology, UC-Biotech, University of Coimbra, Portugal
| | - Paulo J Oliveira
- Center for Neurosciences and Cell Biology, UC-Biotech, University of Coimbra, Portugal
| | - John G Jones
- Center for Neurosciences and Cell Biology, UC-Biotech, University of Coimbra, Portugal.,Portuguese Diabetes Association, Lisbon, Portugal
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Rito J, Viegas I, Pardal MA, Metón I, Baanante IV, Jones JG. Disposition of a Glucose Load into Hepatic Glycogen by Direct and Indirect Pathways in Juvenile Seabass and Seabream. Sci Rep 2018; 8:464. [PMID: 29323287 PMCID: PMC5765127 DOI: 10.1038/s41598-017-19087-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 12/19/2017] [Indexed: 02/06/2023] Open
Abstract
In carnivorous fish, conversion of a glucose load to hepatic glycogen is widely used to assess their metabolic flexibility towards carbohydrate utilization, but the activities of direct and indirect pathways in this setting are unclear. We assessed the conversion of an intraperitoneal glucose load (2 g.kg-1) enriched with [U-13C6]glucose to hepatic glycogen in juvenile seabass and seabream. 13C-NMR analysis of glycogen was used to determine the contribution of the load to glycogen synthesis via direct and indirect pathways at 48-hr post-injection. For seabass, [U-13C6]glucose was accompanied by deuterated water and 2H-NMR analysis of glycogen 2H-enrichment, allowing endogenous substrate contributions to be assessed as well. For fasted seabass and seabream, 47 ± 5% and 64 ± 10% of glycogen was synthesized from the load, respectively. Direct and indirect pathways contributed equally (25 ± 3% direct, 21 ± 1% indirect for seabass; 35 ± 7% direct, 29 ± 4% indirect for seabream). In fasted seabass, integration of 2H- and 13C-NMR analysis indicated that endogenous glycerol and anaplerotic substrates contributed an additional 7 ± 2% and 7 ± 1%, respectively. In fed seabass, glucose load contributions were residual and endogenous contributions were negligible. Concluding, direct and indirect pathways contributed equally and substantially to fasting hepatic glycogen repletion from a glucose load in juvenile seabream and seabass.
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Affiliation(s)
- João Rito
- CNC - Center for Neuroscience and Cell Biology, Rua Larga, 1° Piso da FMUC, University of Coimbra, 3004-504, Coimbra, Portugal
- CFE - Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456, Coimbra, Portugal
| | - Ivan Viegas
- CNC - Center for Neuroscience and Cell Biology, Rua Larga, 1° Piso da FMUC, University of Coimbra, 3004-504, Coimbra, Portugal
- CFE - Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456, Coimbra, Portugal
| | - Miguel A Pardal
- CFE - Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456, Coimbra, Portugal
| | - Isidoro Metón
- Secció de Bioquímica i Biologia Molecular, Departament de Bioquímica i Fisiologia, Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona (UB), Joan XXIII 27, 08028, Barcelona, Spain
| | - Isabel V Baanante
- Secció de Bioquímica i Biologia Molecular, Departament de Bioquímica i Fisiologia, Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona (UB), Joan XXIII 27, 08028, Barcelona, Spain
| | - John G Jones
- CNC - Center for Neuroscience and Cell Biology, Rua Larga, 1° Piso da FMUC, University of Coimbra, 3004-504, Coimbra, Portugal.
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Abstract
Gluconeogenesis is a complex metabolic process that involves multiple enzymatic steps regulated by myriad factors, including substrate concentrations, the redox state, activation and inhibition of specific enzyme steps, and hormonal modulation. At present, the most widely accepted technique to determine gluconeogenesis is by measuring the incorporation of deuterium from the body water pool into newly formed glucose. However, several techniques using radioactive and stable-labeled isotopes have been used to quantitate the contribution and regulation of gluconeogenesis in humans. Each method has its advantages, methodological assumptions, and set of propagated errors. In this review, we examine the strengths and weaknesses of the most commonly used stable isotopes methods to measure gluconeogenesis in vivo. We discuss the advantages and limitations of each method and summarize the applicability of these measurements in understanding normal and pathophysiological conditions.
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Affiliation(s)
- Stephanie T Chung
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
| | - Shaji K Chacko
- U.S. Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Agneta L Sunehag
- U.S. Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Morey W Haymond
- U.S. Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX
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5
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Mallad A, Hinshaw L, Dalla Man C, Cobelli C, Basu R, Lingineni R, Carter RE, Kudva YC, Basu A. Nocturnal Glucose Metabolism in Type 1 Diabetes: A Study Comparing Single Versus Dual Tracer Approaches. Diabetes Technol Ther 2015; 17:587-95. [PMID: 26121060 PMCID: PMC4528985 DOI: 10.1089/dia.2015.0011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Understanding the effect size, variability, and underlying physiology of the dawn phenomenon is important for next-generation closed-loop control algorithms for type 1 diabetes (T1D). SUBJECTS AND METHODS We used an iterative protocol design to study 16 subjects with T1D on individualized insulin pump therapy for two successive nights. Endogenous glucose production (EGP) rates at 3 a.m. and 7 a.m. were measured with [6,6-(2)H(2)]glucose as a single tracer, infused from midnight to 7 a.m. in all subjects. To explore possibility of tracer recycling due to prolonged [6,6-(2)H(2)]glucose infusion, which was highly probable after preplanned interim data analyses, we infused a second tracer, [6-(3)H]glucose, from 4 a.m. to 7 a.m. in the last seven subjects to measure EGP at 7 a.m. RESULTS Cortisol concentrations increased during both nights, but changes in glucagon and insulin concentration were inconsistent. Although the plasma glucose concentrations rose from midnight to 7 a.m. during both nights, EGP measured with [6,6-(2)H(2)]glucose between 3 a.m. and 7 a.m. did not differ during Night 1 but fell in Night 2. However, EGP measured with [6-(3)H]glucose at 7 a.m. was higher than that measured with [6,6-(2)H(2)]glucose during both nights, thereby suggesting tracer recycling probably underestimating EGP calculated at 7 a.m. with [6,6-(2)H(2)]glucose. Likewise, EGP was higher at 7 a.m. with [6-(3)H]glucose than at 3 a.m. with [6,6-(2)H(2)]glucose during both nights. CONCLUSIONS The data demonstrate a consistent overnight rise in glucose concentrations through increased EGP, mediated likely by rising cortisol concentrations. The observations with the dual tracer approach imply significant tracer recycling leading to underestimation of EGP measured by longer-duration tracer infusion.
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Affiliation(s)
- Ashwini Mallad
- Department of Endocrinology, Mayo Clinic, Rochester, Minnesota
| | - Ling Hinshaw
- Department of Endocrinology, Mayo Clinic, Rochester, Minnesota
| | - Chiara Dalla Man
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Claudio Cobelli
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Rita Basu
- Department of Endocrinology, Mayo Clinic, Rochester, Minnesota
| | - Ravi Lingineni
- Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota
| | - Rickey E. Carter
- Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota
| | - Yogish C. Kudva
- Department of Endocrinology, Mayo Clinic, Rochester, Minnesota
| | - Ananda Basu
- Department of Endocrinology, Mayo Clinic, Rochester, Minnesota
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Disposition of [U-2H7]glucose into hepatic glycogen in rat and in seabass. Comp Biochem Physiol A Mol Integr Physiol 2013; 166:316-22. [PMID: 23838145 DOI: 10.1016/j.cbpa.2013.07.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 06/17/2013] [Accepted: 07/01/2013] [Indexed: 11/20/2022]
Abstract
The stimulation of hepatic glycogenesis is a ubiquitous response to a glucose challenge and quantifying its contribution to glucose uptake informs its role in restoring euglycemia. Glycogenesis can be quantified with labeled water provided that exchange of glucose-6-phosphate hydrogen 2 (G6P-H2) and body water via glucose-6-phosphate isomerase, and exchange of positions 4, 5 and 6 hydrogens (G6P-H456) via transaldolase, are known. These exchanges were quantified in 24-h fasted rats (Rattus norvegicus; n=6) and 21-day fasted seabass (Dicentrarchus labrax; n=8) by administration of a glucose load (2000mg·kg(-1)) enriched with [U-(2)H7]glucose and by quantifying hepatic glycogen (2)H-enrichments after 2h (rats) and 48h (seabass). Direct pathway contributions of the glucose load to glycogenesis were also estimated. G6P-H2 and body water exchange was 61±1% for rat and 47±3% for seabass. Transaldolase-mediated exchange of G6P-H456 was 5±1% for rat and 10±1% for seabass. Conversion of the glucose load to hepatic glycogen was significant in seabass (249±54mg·kg(-1)) but negligible in rats (12±1mg·kg(-1)). Preload plasma glucose levels were similar for seabass and rats (3.3±0.7 and 4.4±0.1mmol·L(-1), respectively) but post-load plasma glucose was significantly higher in seabass compared to rats (14.6±1.8 versus 5.8±0.3mmol·L(-1), p<0.01). In conclusion, G6P-H2 and body water exchange is incomplete for both species and has to be accounted for in estimating hepatic glycogen synthesis and direct pathway activities with labeled water tracers. Transaldolase-mediated exchange is insignificant. Hepatic direct pathway glycogenesis plays a prominent role in seabass glucose load disposal, but a negligible role in the rat.
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7
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Barosa C, Silva C, Fagulha A, Barros L, Caldeira MM, Carvalheiro M, Jones JG. Sources of hepatic glycogen synthesis following a milk-containing breakfast meal in healthy subjects. Metabolism 2012; 61:250-4. [PMID: 21862086 DOI: 10.1016/j.metabol.2011.06.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Revised: 06/08/2011] [Accepted: 06/26/2011] [Indexed: 11/20/2022]
Abstract
During feeding, dietary galactose is a potential source of hepatic glycogen synthesis; but its contribution has not been measured to date. In the presence of deuterated water ((2)H(2)O), uridine diphosphate (UDP)-glucose derived from galactose is not enriched, whereas the remainder derived from glucose-6-phosphate (G6P) is enriched in position 2 to the same level as body water, assuming complete G6P-fructose-6-phosphate (F6P) exchange. Hence, the difference between UDP-glucose position 2 and body water enrichments reflects the contribution of galactose to glycogen synthesis relative to all other sources. In study 1, G6P-F6P exchange in 6 healthy subjects was quantified by supplementing a milk-containing breakfast meal with 10 g of [U-(2)H(7)]glucose and quantifying the depletion of position 2 enrichment in urinary menthol glucuronide. In study 2, another 6 subjects ingested (2)H(2)O and acetaminophen followed by an identical breakfast meal with 10 g of [1-(13)C]glucose to resolve direct/indirect pathways and galactose contributions to glycogen synthesis. Metabolite enrichments were determined by (2)H and (13)C nuclear magnetic resonance. In study 1, G6P-F6P exchange approached completion; therefore, the difference between position 2 and body water enrichments in study 2 (0.20% ± 0.03% vs 0.27% ± 0.03%, P < .005) was attributed to galactose glycogenesis. Dietary galactose contributed 19% ± 3% to glycogen synthesis. Of the remainder, 58% ± 5% was derived from the direct pathway and 22% ± 4% via the indirect pathway. The contribution of galactose to hepatic glycogen synthesis was resolved from that of direct and indirect pathways using a combination of (2)H(2)O and [1-(13)C]glucose tracers.
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Affiliation(s)
- Cristina Barosa
- Biophysics and Biomedical NMR, Center for Neurosciences and Cell Biology, University of Coimbra, 3001-401 Coimbra, Portugal
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8
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Kacerovsky M, Jones J, Schmid AI, Barosa C, Lettner A, Kacerovsky-Bielesz G, Szendroedi J, Chmelik M, Nowotny P, Chandramouli V, Wolzt M, Roden M. Postprandial and fasting hepatic glucose fluxes in long-standing type 1 diabetes. Diabetes 2011; 60:1752-8. [PMID: 21562079 PMCID: PMC3114392 DOI: 10.2337/db10-1001] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Intravenous insulin infusion partly improves liver glucose fluxes in type 1 diabetes (T1D). This study tests the hypothesis that continuous subcutaneous insulin infusion (CSII) normalizes hepatic glycogen metabolism. RESEARCH DESIGN AND METHODS T1D with poor glycemic control (T1Dp; HbA(1c): 8.5 ± 0.4%), T1D with improved glycemic control on CSII (T1Di; 7.0 ± 0.3%), and healthy humans (control subjects [CON]; 5.2 ± 0.4%) were studied. Net hepatic glycogen synthesis and glycogenolysis were measured with in vivo (13)C magnetic resonance spectroscopy. Endogenous glucose production (EGP) and gluconeogenesis (GNG) were assessed with [6,6-(2)H(2)]glucose, glycogen phosphorylase (GP) flux, and gluconeogenic fluxes with (2)H(2)O/paracetamol. RESULTS When compared with CON, net glycogen synthesis was 70% lower in T1Dp (P = 0.038) but not different in T1Di. During fasting, T1Dp had 25 and 42% higher EGP than T1Di (P = 0.004) and CON (P < 0.001; T1Di vs. CON: P = NS). GNG was 74 and 67% higher in T1Dp than in T1Di (P = 0.002) and CON (P = 0.001). In T1Dp, GP flux (7.0 ± 1.6 μmol ⋅ kg(-1) ⋅ min(-1)) was twofold higher than net glycogenolysis, but comparable in T1Di and CON (3.7 ± 0.8 and 4.9 ± 1.0 μmol ⋅ kg(-1) ⋅ min(-1)). Thus T1Dp exhibited glycogen cycling (3.5 ± 2.0 μmol ⋅ kg(-1) ⋅ min(-1)), which accounted for 47% of GP flux. CONCLUSIONS Poorly controlled T1D not only exhibits augmented fasting gluconeogenesis but also increased glycogen cycling. Intensified subcutaneous insulin treatment restores these abnormalities, indicating that hepatic glucose metabolism is not irreversibly altered even in long-standing T1D.
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Affiliation(s)
- Michaela Kacerovsky
- Karl-Landsteiner Institute for Endocrinology and Metabolism, Vienna, Austria
| | - John Jones
- Department of Life Sciences and Center for Neurosciences and Cell Biology, University of Coimbra, Coimbra, Portugal
- Portuguese Diabetes Association, Rua do Salitre, Lisbon, Portugal
| | - Albrecht I. Schmid
- Karl-Landsteiner Institute for Endocrinology and Metabolism, Vienna, Austria
- MR Center of Excellence, Medical University of Vienna, Vienna, Austria
| | - Cristina Barosa
- Department of Life Sciences and Center for Neurosciences and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Angelika Lettner
- Karl-Landsteiner Institute for Endocrinology and Metabolism, Vienna, Austria
| | - Gertrud Kacerovsky-Bielesz
- Karl-Landsteiner Institute for Endocrinology and Metabolism, Vienna, Austria
- 1st Medical Department, Hanusch Hospital, Vienna, Austria
| | - Julia Szendroedi
- Karl-Landsteiner Institute for Endocrinology and Metabolism, Vienna, Austria
- 1st Medical Department, Hanusch Hospital, Vienna, Austria
- Institute for Clinical Diabetology, German Diabetes Center (Leibniz Center for Diabetes Research), Düsseldorf, Germany
- Department of Metabolic Diseases, Heinrich-Heine University and University Clinics Düsseldorf, Düsseldorf, Germany
| | - Marek Chmelik
- Karl-Landsteiner Institute for Endocrinology and Metabolism, Vienna, Austria
- MR Center of Excellence, Medical University of Vienna, Vienna, Austria
| | - Peter Nowotny
- Institute for Clinical Diabetology, German Diabetes Center (Leibniz Center for Diabetes Research), Düsseldorf, Germany
| | - Visvanathan Chandramouli
- Department of Medicine, University Hospitals Case Medical Center, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Michael Wolzt
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Michael Roden
- Karl-Landsteiner Institute for Endocrinology and Metabolism, Vienna, Austria
- 1st Medical Department, Hanusch Hospital, Vienna, Austria
- Institute for Clinical Diabetology, German Diabetes Center (Leibniz Center for Diabetes Research), Düsseldorf, Germany
- Department of Metabolic Diseases, Heinrich-Heine University and University Clinics Düsseldorf, Düsseldorf, Germany
- Corresponding author: Michael Roden,
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9
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Soares AF, Carvalho RA, Veiga FJ, Jones JG. Effects of galactose on direct and indirect pathway estimates of hepatic glycogen synthesis. Metab Eng 2010; 12:552-60. [PMID: 20797446 DOI: 10.1016/j.ymben.2010.08.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Revised: 07/07/2010] [Accepted: 08/16/2010] [Indexed: 11/15/2022]
Abstract
Hepatic glycogen is formed by direct and indirect pathways whose activities reflect altered nutrition or disease. Direct/indirect pathway measurements often involve test meals where ∼ 10% of carbohydrate is galactose, but its effects on direct/indirect pathway estimates are unknown. Therefore, direct/indirect pathway contributions in 24-h fasted rats given 2g/kg 100% glucose (GLU, n=6) or 90% glucose-10% galactose (GLU+GAL, n=6) were measured by [U-(13)C]glucose dilution and by position-5/position-2 glycogen enrichment (H5/H2) from 2H(2)O. For GLU+GAL, galactose glycogenesis was independently measured with [1-(13)C]galactose. Glycogenesis was equivalent in both groups but for GLU+GAL, 23 ± 4% of glycogen was derived from galactose. [U-(13)C]glucose reported a 30 ± 3% direct pathway contribution to glycogenesis for GLU but only 20 ± 3% for GLU+GAL (p=0.012 vs. GLU). H5/H2 yielded identical direct pathway estimates (32 ± 3% GLU, 29 ± 6% GLU+GAL). Thus, galactose glycogenesis was undetected by H5/H2 while [U-(13)C]glucose reported a reduced direct/indirect pathway ratio. With [1-(13)C]galactose also present, correct glycogenic source contributions were obtained.
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Affiliation(s)
- Ana F Soares
- Department of Life Sciences and Center for Neurosciences and Cell Biology, University of Coimbra, Rua dos Estudos, Apartado 3126, 3001-401 Coimbra, Portugal
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10
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Luengo C, Azzout-Marniche D, Fromentin C, Piedcoq J, Lemosquet S, Tomé D, Gaudichon C. [13C] GC-C-IRMS analysis of methylboronic acid derivatives of glucose from liver glycogen after the ingestion of [13C] labeled tracers in rats. J Chromatogr B Analyt Technol Biomed Life Sci 2009; 877:3638-44. [PMID: 19775945 DOI: 10.1016/j.jchromb.2009.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2009] [Revised: 08/28/2009] [Accepted: 09/02/2009] [Indexed: 11/26/2022]
Abstract
We developed a complete method to measure low [(13)C] enrichments in glycogen. Fourteen rats were fed a control diet. Six of them also ingested either [U-(13)C] glucose (n=2) or a mixture of 20 [U-(13)C] amino acids (n=4). Hepatic glycogen was extracted, digested to glucose and purified on anion-cation exchange resins. After the optimization of methylboronic acid derivatization using GC-MS, [(13)C] enrichment of extracted glucose was measured by GC-C-IRMS. The accuracy was addressed by measuring the enrichment excess of a calibration curve, which observed values were in good agreement with the expected values (R=0.9979). Corrected delta values were -15.6+/-1.6 delta(13)C (per thousand) for control rats (n=8) and increased to -5 to 8 delta(13)C (per thousand) per thousand and 12-14 delta(13)C (per thousand) per thousand after the ingestion of [U-(13)C] amino acids or [U-(13)C] glucose as oral tracers, respectively. The method enabled the determination of dietary substrate transfer into glycogen. The sequestration of dietary glucose in liver glycogen 4 h after the meal was 35% of the ingested dose whereas the transfer of carbon skeletons from amino acids was only 0.25 to 1%.
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Affiliation(s)
- Catherine Luengo
- INRA, CNRH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, F-75005 Paris, France
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11
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Delgado T, Barosa C, Castro M, Geraldes C, Bastos M, Baptista C, Fagulha A, Barros L, Mota A, Carvalheiro M, Jones J, Merritt M. Sources of hepatic glucose production by2H2O ingestion and Bayesian analysis of2H glucuronide enrichment. Magn Reson Med 2008; 60:517-23. [DOI: 10.1002/mrm.21681] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Jones JG, Garcia P, Barosa C, Delgado TC, Caldeira MM, Diogo L. Quantification of hepatic transaldolase exchange activity and its effects on tracer measurements of indirect pathway flux in humans. Magn Reson Med 2008; 59:423-9. [DOI: 10.1002/mrm.21451] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Bock G, Schumann WC, Basu R, Burgess SC, Yan Z, Chandramouli V, Rizza RA, Landau BR. Evidence that processes other than gluconeogenesis may influence the ratio of deuterium on the fifth and third carbons of glucose: implications for the use of 2H2O to measure gluconeogenesis in humans. Diabetes 2008; 57:50-5. [PMID: 17934142 DOI: 10.2337/db07-0694] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE The deuterated water method uses the ratio of deuterium on carbons 5 and 2 (C5/C2) or 3 and 2 (C3/C2) to estimate the fraction of glucose derived from gluconeogenesis. The current studies determined whether C3 and C5 glucose enrichment is influenced by processes other than gluconeogenesis. RESEARCH DESIGN AND METHODS Six nondiabetic subjects were infused with [3,5-(2)H(2)]glucose and insulin while glucose was clamped at approximately 5 mmol/l; the C5-to-C3 ratio was measured in the in UDP-glucose pool using nuclear magnetic resonance and the acetaminophen glucuronide method. RESULTS Whereas the C5-to-C3 ratio of the infusate was 1.07, the ratio in UDP-glucose was <1.0 in all subjects both before (0.75 +/- 0.07) and during (0.67 +/- 0.05) the insulin infusion. CONCLUSIONS These data indicate that the deuterium on C5 of glucose is lost more rapidly relative to the deuterium on C3. The decrease in the C5-to-C3 ratio could result from exchange of the lower three carbons of fructose-6-phosphate with unlabeled three-carbon precursors via the transaldolase reaction and/or selective retention of the C3 deuterium at the level of triosephosphate isomerase due to a kinetic isotope effect. After ingestion of (2)H(2)O, these processes would increase the enrichment of C5 and decrease the enrichment of C3, respectively, with the former causing an overestimation of gluconeogenesis using the C2-to-C5 ratio and the latter an underestimation using the C3-to-C2 ratio. Future studies will be required to determine whether the impact of these processes on the measurement of gluconeogenesis differs among the disease states being evaluated (e.g., diabetes or obesity).
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Affiliation(s)
- Gerlies Bock
- Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Department of Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA
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Sena CM, Barosa C, Nunes E, Seiça R, Jones JG. Sources of endogenous glucose production in the Goto–Kakizaki diabetic rat. DIABETES & METABOLISM 2007; 33:296-302. [PMID: 17553720 DOI: 10.1016/j.diabet.2007.03.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2006] [Accepted: 03/18/2007] [Indexed: 10/23/2022]
Abstract
Plasma glucose, insulin and glucose tolerance were quantified in diabetic Goto-Kakizaki (GK) rats (342+/-45 g, n = 5) and compared with weight-matched non-diabetic Wistars (307+/-30 g, n = 8). Compared to Wistars, GK rats had higher fasting plasma insulin (219+/-50 versus 44+/-14 pmol/l, P<0.002) and glucose (9.2+/-2.3 versus 5.5+/-0.5 mmol/l, P<0.025). GK rats showed impaired glucose tolerance (IPGTT 2 h plasma glucose=14+/-1.5 versus 6.4+/-0.1 mmol/l, P<0.001). Endogenous glucose production (EGP) from glycogenolysis, phosphoenolpyruvate (PEP) and glycerol after 6 hours of fasting was quantified by a primed infusion of [U-(13)C]glucose and (2)H(2)O tracers and (2)H/(13)C NMR analysis of plasma glucose. EGP was higher in GK compared to Wistar rats (191+/-16 versus 104+/-27 mumol/kg per min, P<0.005). This was sustained by increased gluconeogenesis from PEP (85+/-12 versus 35+/-4 mumol/kg per min, P<0.02). Gluconeogenesis from glycerol was not different (20+/-3 in Wistar versus 30+/-6 mumol/kg per min for GK), and glycogenolysis fluxes were also not significantly different (76+/-23 mumol/kg per min for GK versus 52+/-19 mumol/kg per min for Wistar). The Cori cycle accounted for most of PEP gluconeogenesis in both Wistar and GK rats (85+/-15% and 77+/-10%, respectively). Therefore, increased gluconeogenesis in GK rats is largely sustained by increased Cori cycling while the maintenance of glycogenolysis indicates a failure in hepatic autoregulation of EGP.
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Affiliation(s)
- C M Sena
- Institute of Physiology, Faculty of Medicine, University of Coimbra, Rua Larga, 3004-504 Coimbra, Portugal.
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Staehr P, Hother-Nielsen O, Beck-Nielsen H, Roden M, Stingl H, Holst JJ, Jones PK, Chandramouli V, Landau BR. Hepatic autoregulation: response of glucose production and gluconeogenesis to increased glycogenolysis. Am J Physiol Endocrinol Metab 2007; 292:E1265-9. [PMID: 17213474 DOI: 10.1152/ajpendo.00411.2006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effect of increased glycogenolysis, simulated by galactose's conversion to glucose, on the contribution of gluconeogenesis (GNG) to hepatic glucose production (GP) was determined. The conversion of galactose to glucose is by the same pathway as glycogen's conversion to glucose, i.e., glucose 1-phosphate --> glucose 6-phosphate --> glucose. Healthy men (n = 7) were fasted for 44 h. At 40 h, hepatic glycogen stores were depleted. GNG then contributed approximately 90% to a GP of approximately 8 micromol.kg(-1).min(-1). Galactose, 9 g/h, was infused over the next 4 h. The contribution of GNG to GP declined from approximately 90% to 65%, i.e., by approximately 2 micromol.kg(-1).min(-1). The rate of galactose conversion to blood glucose, measured by labeling the infused galactose with [1-(2)H]galactose (n = 4), was also approximately 2 micromol.kg(-1).min(-1). The 41st h GP rose by approximately 1.5 micromol.kg(-1).min(-1) and then returned to approximately 9 micromol.kg(-1).min(-1), while plasma glucose concentration increased from approximately 4.5 to 5.3 mM, accompanied by a rise in plasma insulin concentration. Over 50% of the galactose infused was accounted for in blood glucose and hepatic glycogen formation. Thus an increase in the rate of GP via the glycogenolytic pathway resulted in a concomitant decrease in the rate of GP via GNG. While the compensatory response to the galactose administration was not complete, since GP increased, hepatic autoregulation is operative in healthy humans during prolonged fasting.
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Affiliation(s)
- Peter Staehr
- Medical Endocrinological Department, Odense University Hospital, Odense, Denmark
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Jones JG, Fagulha A, Barosa C, Bastos M, Barros L, Baptista C, Caldeira MM, Carvalheiro M. Noninvasive analysis of hepatic glycogen kinetics before and after breakfast with deuterated water and acetaminophen. Diabetes 2006; 55:2294-300. [PMID: 16873693 DOI: 10.2337/db06-0304] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The contributions of hepatic glycogenolysis to fasting glucose production and direct pathway to hepatic glycogen synthesis were quantified in eight type 1 diabetic patients and nine healthy control subjects by ingestion of (2)H(2)O and acetaminophen before breakfast followed by analysis of urinary water and acetaminophen glucuronide. After overnight fasting, enrichment of glucuronide position 5 relative to body water (G5/body water) was significantly higher in type 1 diabetic patients compared with control subjects, indicating a reduced contribution of glycogenolysis to glucose production (38 +/- 3 vs. 46 +/- 2%). Following breakfast, G5/body water was significantly higher in type 1 diabetic patients, indicating a smaller direct pathway contribution to glycogen synthesis (47 +/- 2 vs. 59 +/- 2%). Glucuronide hydrogen 2 enrichment (G2) was equivalent to body water during fasting (G2/body water 0.94 +/- 0.03 and 1.02 +/- 0.06 for control and type 1 diabetic subjects, respectively) but was significantly lower after breakfast (G2/body water 0.78 +/- 0.03 and 0.82 +/- 0.05 for control and type 1 diabetic subjects, respectively). The reduced postprandial G2 levels reflect incomplete glucose-6-phosphate-fructose-6-phosphate exchange or glycogen synthesis from dietary galactose. Unlike current measurements of human hepatic glycogen metabolism, the (2)H(2)O/acetaminophen assay does not require specialized on-site clinical equipment or personnel.
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Affiliation(s)
- John G Jones
- NMR Research Unit, Department of Biochemistry and Center for Neurosciences and Cell Biology, Faculty of Sciences and Technology, University of Coimbra, 3001-401 Coimbra, Portugal.
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