International Journal of Experimental Diabetes Research
Volume 3 (2002), Issue 3, Pages 163-169
doi:10.1080/15604280214280
Fasting Decreases the Content of D-Chiroinositol in Human Skeletal Muscle
1Department of Internal Medicine, University of Virginia Charlottesville, Charlottesville, Virginia, USA
2Department of Pharmacology, University of Virginia Charlottesville, Charlottesville, Virginia, USA
3Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm 171 77 , Sweden
Received 28 October 2001; Accepted 21 February 2002
Copyright © 2002 Pavel N. Shashkin et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Two classes of inositol phosphoglycans have been implicated as
second messengers of insulin, one that activates pyruvate dehydrogenase
and contains D-chiroinositol, and one that inhibits cyclic
AMP–dependent protein kinase and contains myoinositol. We examined
the effects of a 3-day fast on muscle contents of inositols
in healthy humans. An oral glucose tolerance test was performed
and a biopsy was obtained from the quadriceps femoris muscle
after an overnight fast and after a 72-hour fast. The 72-hour fast
significantly increased plasma glucose (1.5- to 2-fold) and insulin
(2- to 4-fold) after glucose ingestion versus the values after the
overnight fast, indicating the manifestation of peripheral insulin
resistance. The 72-hour fast resulted in an ∼20% decrease in the
muscle content of D-chiroinositol (P < 0.02), but no change in the
myoinositol content. These data demonstrate that fasting specifically
decreases the muscle content of D-chiroinositol in human muscle
and this may contribute to the finding that insulin-mediated activation
of pyruvate dehydrogenase is attenuated after short-term
starvation.