Determination of plasma [6,6-2H2]glucose enrichment by a simple and accurate gas chromatographic-mass spectrometric method.
An improved method for the evaluation of glucose turnover rate in humans, using a prime-continuous infusion of [6,6-2H2]glucose, was developed. Deproteinization of plasma and conversion of glucose into the aldononitrile pentaacetate derivative are the only sample manipulations required prior to the gas chromatographic-mass spectrometric analysis. In six normal adults (prime = 5 mg kg-1; continuous infusion = 0.05 mg kg-1 min-1) the hepatic glucose output calculated at steady state by the procedure described here was 2.1 +/- 0.2 mg kg-1 min-1, the isotopic enrichment being determined with a coefficient of variation of ca. 2%. In six additional subjects, with half of the above-mentioned doses of labelled glucose, the mean hepatic glucose output was exactly the same (3.2% coefficient of variation for the isotopic enrichment measurement). The method described allows the hepatic glucose output to be precisely determined with savings both of time and of labelled glucose.
Magni
F
F
Department of Medicine, Scientific Institute S. Raffaele, Milan, Italy.
Monti
L
L
Brambilla
P
P
Poma
R
R
Pozza
G
G
Galli Kienle
M
M
D001786:Blood Glucose / Q000032:analysis*; D003903:Deuterium; D008401:Gas Chromatography-Mass Spectrometry; D005947:Glucose / Q000378:metabolism; D006801:Humans; D008099:Liver / Q000378:metabolism
D001786:Blood Glucose; D003903:Deuterium; D005947:Glucose