Application of deuterium oxide (D 2 O) to metabolic research: just D 2 O it? Depends just how you D 2 O it!
2015; American Physiological Society; Volume: 308; Issue: 9 Linguagem: Inglês
10.1152/ajpendo.00581.2014
ISSN1522-1555
AutoresDaniel J. Wilkinson, Philip J. Atherton, Bethan E. Phillips, Paul L. Greenhaff, Kenneth Smith,
Tópico(s)Pharmacology and Obesity Treatment
ResumoLetter to the EditorApplication of deuterium oxide (D2O) to metabolic research: just D2O it? Depends just how you D2O it!Daniel J. Wilkinson, Philip J. Atherton, Bethan E. Phillips, Paul L. Greenhaff, and Kenneth SmithDaniel J. WilkinsonDivision of Medical Sciences and Graduate Entry Medicine, Medical Research Council-Arthritis Research United Kingdom Centre of Excellence for Musculoskeletal Ageing Research, Royal Derby Hospital Centre, University of Nottingham, Derby, United Kingdom; and , Philip J. AthertonDivision of Medical Sciences and Graduate Entry Medicine, Medical Research Council-Arthritis Research United Kingdom Centre of Excellence for Musculoskeletal Ageing Research, Royal Derby Hospital Centre, University of Nottingham, Derby, United Kingdom; and , Bethan E. PhillipsDivision of Medical Sciences and Graduate Entry Medicine, Medical Research Council-Arthritis Research United Kingdom Centre of Excellence for Musculoskeletal Ageing Research, Royal Derby Hospital Centre, University of Nottingham, Derby, United Kingdom; and , Paul L. GreenhaffSchool of Life Sciences, Queens Medical Centre, Nottingham, United Kingdom, and Kenneth SmithDivision of Medical Sciences and Graduate Entry Medicine, Medical Research Council-Arthritis Research United Kingdom Centre of Excellence for Musculoskeletal Ageing Research, Royal Derby Hospital Centre, University of Nottingham, Derby, United Kingdom; and Published Online:01 May 2015https://doi.org/10.1152/ajpendo.00581.2014MoreSectionsPDF (32 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations to the editor: the recent article by Lambert et al. (4) reports the effects of aquatic vs. land-based aerobic treadmill exercise combined with resistance exercise in the context of muscle anabolism. These authors quantified muscle protein synthesis (MPS) over 24 h using a method that has garnered a great deal of interest over the past few years, i.e., deuterium oxide (D2O), or “heavy water.” We are ardent advocates of the application of stable isotope tracers to the study of physiology and metabolism; nonetheless, we feel it is imperative that such specialist techniques are scrutinized carefully to ensure that they have been applied and analyzed with rigor. If not, then erroneous conclusions could and no doubt have been drawn. In Fig. 3 of the article by Lambert et al. (4), rates of MPS (myofibrillar) were reported as ∼8–15%/day. This is approximately five to 10 times greater than what is normally observed in healthy human skeletal muscles when conventional amino acid tracers are employed (0.07–0.15%/h, 1.6–3%/day) (3, 6). Moreover, utilizing the same D2O tracer techniques (albeit more sensitive, accurate mass spectrometric techniques, i.e., gas chromatography-pyrolysis-isotope ratio mass spectrometry), we recently demonstrated rates of MPS, even after resistance exercise in the fed state, of ∼2%/day (7). Lambert et al. (4) provide limited details of their analytical methods but reference previously coauthored papers detailing past work using this approach. In one such paper (1), they describe similarly high MPS (∼0.7–0.9%/h) again eight to 10 times that typically observed; this time, however, they acknowledge the discrepancy in the discussion without providing a convincing explanation (1). Moreover, earlier work by the same authors reports MPS of ∼0.2–0.9%/h in 6- to 8-mo-old (i.e., growing) exercising rats (2). Although these MPS rates are more consistent with those reported for rat muscles (5), how do these authors explain humans and rats having similar rates of MPS?Based on the information provided in Lambert et al. (4) and previous (1, 2) papers, we believe that any analytical related shortfalls leading to such incongruent rates of MPS should be reconciled. For example, Gasier et al. (1) reported that, due to low levels of enrichment ( Volume 308Issue 9May 2015Pages E847-E847 Copyright & PermissionsCopyright © 2015 the American Physiological Societyhttps://doi.org/10.1152/ajpendo.00581.2014PubMed25934906History Received 10 December 2014 Accepted 13 January 2015 Published online 1 May 2015 Published in print 1 May 2015 Metrics
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