Encontrados 20 documentos, a visualizar página 1 de 2
Disposition of [U-2H7]glucose into hepatic glycogen in rat and in seabass
Martins, Fátima O.; Rito, João; Jarak, Ivana; Viegas, Ivan; Pardal, M. A.; Macedo, M. Paula; Jones, John G.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 trans...
Hepatic anaplerotic outflow fluxes are redirected from gluconeogenesis to lacta...
Jones, John G.; Garcia, Paula; Barosa, Cristina; Delgado, Teresa C.; Diogo, Luisahttp://www.sciencedirect.com/science/article/B6WN3-4VJ0DT5-1/2/787b10f4d5c8351d470d0ee77de680d4
Elimination of glucose contamination from adipocyte glycogen extracts
Nunes, Patricia M.; Carvalho, Eugénia; Jones, John G.Glycogen was quantified in rat adipocytes by isolation using conventional KOH digestion and ethanol precipitation, followed by hydrolysis and spectrophotometric assay of the glucose product. A concentration of 0.193 ± 0.020 [mu]mol glucosyl units/106 cells was recorded. When this procedure was modified by including a 4 h incubation with glucose oxidase prior to glycogen hydrolysis, the glycogen concentration wa...
Quantification of hepatic transaldolase exchange activity and its effects on tr...
Jones, John G.; Garcia, Paula; Barosa, Cristina; Delgado, Teresa C.; Caldeira, M. Madalena; Diogo, LuisaExchange of hepatic glucose-6-phosphate (G6P) and glyceraldehyde-3-phosphate via transaldolase modifies hepatic G6P enrichment from glucose or gluconeogenic tracers. Transaldolase exchange was quantified in five healthy, fed subjects following an oral bolus of [1,2,3-13C3]glycerol (25-30 mg/kg) and paracetamol (10-12 mg/kg). 13C Isotopomers of hepatic G6P were quantified by 13C NMR spectroscopy of urinary glucu...
Metabolic characterisation of plasma in juveniles with glycogen storage disease...
Duarte, Iola F.; Goodfellow, Brian J.; Barros, António; Jones, John G.; Barosa, Cristina; Diogo, Luisa; Garcia, Paula; Gil, Ana M.This paper reports the first application of high-resolution 1H NMR spectroscopy to the plasma of five juveniles with glycogen storage disease type 1a (GSD1a), permitting the characterisation of the plasma metabolic profile and the identification of alterations relative to a set of control samples. The relaxation-weighted spectra allowed changes in low molecular weight compounds to be detected more clearly, wher...
Hepatic UDP-glucose 13C isotopomers from [U-13C]glucose: A simple analysis by 1...
Mendes, Ana C.; Caldeira, M. Madalena; Silva, Cláudia; Burgess, Shawn C.; Merritt, Matthew E.; Gomes, Filipe; Barosa, Cristina; Delgado, Teresa C.Menthol glucuronide was isolated from the urine of a healthy 70-kg female subject following ingestion of 400 mg of peppermint oil and 6 g of 99% [U-13C]glucose. Glucuronide 13C-excess enrichment levels were 4-6% and thus provided high signal-to-noise ratios (SNRs) for confident assignment of 13C-13C spin-coupled multiplet components within each 13C resonance by 13C NMR. The [U-13C]glucuronide isotopomer derived...
Noninvasive analysis of hepatic glycogen kinetics before and after breakfast wi...
Jones, John G.; Fagulha, Ana; Barosa, Cristina; Bastos, Margarida; Barros, Luisa; Baptista, Carla; Caldeira, M. Madalena; Carvalheiro, ManuelaThe 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...
Uptake and metabolic effects of insulin mimetic oxovanadium compounds in human ...
Delgado, Teresa C.; Tomaz, A. Isabel; Correia, Isabel; Pessoa, João Costa; Jones, John G.; Geraldes, Carlos F. G. C.; Castro, M. Margarida C. A.The uptake of the oxidation products of two oxovanadium(IV) compounds, [N,N'-ethylenebis(pyridoxylaminato)]oxovanadium(IV), VIVO(Rpyr2en), and bis-[3-hydroxy-1,2-dimethyl-4-pyridinonato]oxovanadium(IV), VIVO(dmpp)2, by human erythrocytes was studied using 51V and 1H NMR and EPR spectroscopy. VIVO(Rpyr2en) in aerobic aqueous solution is oxidized to its VV counterpart and the neutral form slowly enters the cells ...
Comparison of [3,4-13C2] glucose as a tracer for glucose turnover by nuclear m...
Jin, Eunsook S.; Jones, John G.; Burgess, Shawn C.; Merritt, Matthew E.; Sherry, A. Dean; Malloy, Craig R.A recently introduced tracer, [3,4-13C2] glucose, was compared to the widely used tracer, [6,6-2H2]glucose, for measurement of whole-body glucose turnover. The rate of glucose production (GP) was measured in rats after primed infusions of [3,4-13C2]glucose, [6,6-2H2]glucose, or both tracers simultaneously followed by a constant infusion of tracer(s) over 90 min. Blood glucose was purified and converted into mon...
Simple measurement of gluconeogenesis by direct 2H NMR analysis of menthol gluc...
Ribeiro, Angela; Caldeira, M. Madalena; Carvalheiro, Manuela; Bastos, Margarida; Baptista, Carla; Fagulha, Ana; Barros, Luisa; Barosa, CristinaThe contribution of gluconeogenesis to fasting glucose production was determined by a simple measurement of urinary menthol glucuronide (MG) 2H enrichment from 2H2O. Following ingestion of 2H2O (0.5% body water) during an overnight fast and a pharmacological dose (400 mg) of a commercial peppermint oil preparation the next morning, 364 mumol MG was quantitatively recovered from a 2-h urine collection by ether e...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||