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Comment
. 2008 Jun;104(6):1852-3; author reply 1854-5.
doi: 10.1152/japplphysiol.90406.2008.

Complicating factors in the application of the "average method" for determining the contribution of gluconeogenesis

Shawn C Burgess, Visvanathan Chandramouli, Jeffrey D Browning, William C Schumann, Stephen F Previs
Comment

Complicating factors in the application of the "average method" for determining the contribution of gluconeogenesis

Shawn C Burgess et al. J Appl Physiol (1985). 2008 Jun.
No abstract available

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Figures

Fig. 1
Fig. 1
2H NMR spectra of plasma glucose (monoacetone glucose derivative) taken from a single human subject 24 and 48 h into a fast demonstrates nonequal deuterium enrichment in H1, H3, H4, H5, H6R, and H6S positions. The protocol and consent form were approved by the Institutional Review Board of the University of Texas Southwestern Medical Center, and all participants provided written informed consent before enrollment. Healthy lean male subjects (n = 4, average body mass index = 23.3) were administered enough 70% 2H2O in 3 divided doses to enrich body water to 0.5% at 12 h into the fast. Thereafter, subjects were allowed free access to 0.5% 2H2O as drinking water. The table shows the enrichments (means ± SE) relative to H2 after 24 and 48 h of fasting. In all cases, H1 was more enriched than H5, while H3, H6R, and H6S were always less enriched than H5; only H4 was similarly enriched as H5. Fractional gluconeogenesis was determined either by H5/H2 or by taking the average (H1, H3, H5, H6R, H6S)/H2, analogous to Chacko et al. (3). The 2 methods gave similar results after a 24-h but not a 48-h fast, indicating that under some conditions, overenrichment of H1 in combination with the underenrichment of H3, H6R, and H6S, when taken as an average, can provide similar values of gluconeogenesis as the H5/H2 method. However, when gluconeogenesis approaches 100%, the “average” method fails to match the H5/H2. Significant differences between H5 enrichment and other positions or between the 2 methods were tested using a paired Student's t-test. NA, not applicable.
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References

    1. Burgess SC, Nuss M, Chandramouli V, Hardin DS, Rice M, Landau BR, Malloy CR, Sherry AD. Analysis of gluconeogenic pathways in vivo by distribution of 2H in plasma glucose: comparison of nuclear magnetic resonance and mass spectrometry. Anal Biochem. 2003;318:321–324. - PubMed
    1. Burgess SC, Weis BC, Jones JG, Smith E, Merritt ME, Margolis D, Sherry AD, Malloy CR. Noninvasive evaluation of liver metabolism by 2H and 13C NMR isotopomer analysis of human urine. Anal Biochem. 2003;312:228–234. - PubMed
    1. Chacko SK, Sunehag AL, Sharma S, Sauer PJJ, Haymond MW. Measurement of gluconeogenesis using glucose fragments and mass spectrometry after ingestion of deuterium oxide. J Appl Physiol. 2008;104:944–951. - PubMed
    1. Chandramouli V, Ekberg K, Schumann WC, Wahren J, Landau BR. Origins of the hydrogen bound to carbon 1 of glucose in fasting: significance in gluconeogenesis quantitation. Am J Physiol Endocrinol Metab. 1999;277:E717–E723. - PubMed
    1. Jones JG, Solomon MA, Cole SM, Sherry AD, Malloy CR. An integrated 2H and 13C NMR study of gluconeogenesis and TCA cycle flux in humans. Am J Physiol Endocrinol Metab. 2001;281:E848–E856. - PubMed