Glucose transport with brief dietary restriction: heterogenous responses in muscles
Cartee, G.D.; Dean, D.J.
American Journal of Physiology 266(6 Pt 1): E946-E952
1994
ISSN/ISBN: 0002-9513 PMID: 8023926 Document Number: 423147
The time course (1, 5, or 20 days) for the effect of dietary restriction (DR; 25% reduction below ad libitum intake) on epitrochlearis and flexor digitorum brevis (FDB) muscle glucose transport activity was studied in female Fischer 344 rats (8 mo old). Epitrochlearis glucose transport activity with 100 mU/ml insulin was increased by 38% after 5 days of DR (P < 0.05) despite no change in glucose transport activity with 0 or 20,000 mU/ml insulin. The increase with 100 mU/ml insulin was not further enhanced by 20 days of DR. DR did not result in a significant increase in the glucose transport activity of the FDB with 0, 100, or 20,000 mU/ml insulin. Abdominal fat content was significantly (P < 0.01) reduced below ad libitum levels only after 20 days of DR. These results demonstrate that DR-induced improvement in epitrochlearis glucose transport activity with a physiological insulin concentration can occur very rapidly, preceding detectable changes in basal or maximal insulin-stimulated glucose transport activity or abdominal fat pad mass, and the enhancement of insulin action does not occur simultaneously in all muscles. Reprinted by permission of the publisher.