In vivo nmr evidence for moderate glucose accumulation in human
skeletal muscle during hyperglycemia.
Roussel, Ronan, Gilberto Velho, Pierre G. Carlier, Laurence Jouvensal,
and Gilles Bloch.
CEA, Service Hospitalier Fr[acute]ed[acute]eric Joliot,
D[acute]epartement de Recherche M[acute]edicale, Orsay, France and
*INSERM U-358, H[circumflex]opital Saint-Louis, Paris, France
APStracts 3:0090E, 1996.
While the absence of intracellular (IC) free glucose is direct
evidence of glucose transport being the rate-limiting step for muscle
glucose disposal at euglycemia, the scarcity of data in humans during
hyperglycemia precludes any definitive conclusion. In the present
study, 13C and 31P in vivo NMR data from two separate groups of
subjects were combined to measure IC free glucose in the human
skeletal muscle. Using these non-invasive tools with an infusion of
[1-13C]glucose, a steady-state concentration of 1.2+/-0.2 mmol IC
glucose/l IC water was observed at the end of a 2-hour hyperglycemic
clamp with somatostatin infusion, during which glycemia was
maintained at nearly equal to 22 mmol/l and insulinemia at nearly
equal to 5 mU/l. In spite of this moderate glucose accumulation, the
persistence of a large transmembrane glucose gradient suggests that
the post-transport steps do not play a significant role in the
control of muscle glucose disposal in these specific conditions,
relevant to insulinopenic diabetic patients.
Received 19 January 1996; accepted in final form 9 April 1996.
APS Manuscript Number E28-6.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 1 May 96