Fasting decreases the content of D-chiroinositol in human skeletal muscle.
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 approximately 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.
Shashkin
Pavel N
PN
Department of Internal Medicine, University of Virginia Charlottesville, Charlottesville, Virginia, USA.
Huang
Laura C
LC
Larner
Joseph
J
Vandenhoff
George E
GE
Katz
Abram
A
D000328:Adult; D005215:Fasting / Q000378:metabolism*; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007294:Inositol / Q000378:metabolism*; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D012016:Reference Values; D013237:Stereoisomerism; D013848:Thigh; D013997:Time Factors
D007294:Inositol