Quantitation of plasma 13C-galactose and 13C-glucose during exercise by liquid chromatography/isotope ratiomass spectrometry

Morrison, D.J. , O'Hara, J.P., King, R.D.G. and Preston, T. (2011) Quantitation of plasma 13C-galactose and 13C-glucose during exercise by liquid chromatography/isotope ratiomass spectrometry. Rapid Communications in Mass Spectrometry, 25(17), pp. 2484-2488. (doi: 10.1002/rcm.5139)

Abstract

The utilisation of carbohydrate sources under exercise conditions is of considerable importance in performance sports. Incorporation of optimal profiles of macronutrients can improve endurance performance in athletes. However, gaining an understanding of the metabolic partitioning under sustained exercise can be problematical and isotope labelling approaches can help quantify substrate utilisation. The utilisation of oral galactose was investigated using 13C-galactose and measurement of plasma galactose and glucose enrichment by liquid chromatography/isotope ratio mass spectrometry (LC/IRMS). As little as 100 mL plasma could readily be analysed with only minimal sample processing. Fucose was used as a chemical and isotopic internal standard for the quantitation of plasma galactose and glucose concentrations, and isotopic enrichment. The close elution of galactose and glucose required a correction routine to be implemented to allow the measurement, and correction, of plasma glucose d13C, even in the presence of very highly enriched galactose. A Bland-Altman plot of glucose concentration measured by LC/IRMS against glucose measured by an enzymatic method showed good agreement between the methods. Data from seven trained cyclists, undergoing galactose supplementation before exercise, demonstrate that galactose is converted into glucose and is available for subsequent energy metabolism.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Preston, Professor Tom and Morrison, Professor Douglas
• Authors: Morrison, D.J., O'Hara, J.P., King, R.D.G., and Preston, T.
• Subjects: Q Science > QP Physiology
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Rapid Communications in Mass Spectrometry
• ISSN: 0951-4198
• Published Online: 04 August 2011