Horm Metab Res 1996; 28(10): 545-548
DOI: 10.1055/s-2007-979849
Originals Clinical

© Georg Thieme Verlag Stuttgart · New York

No Change in Insulin Mediators in Human Skeletal Muscle During Isometric Contraction or Recovery

A. Katz1 , E. Hultma2 , L. Huang3 , C. Villar-Palasi3 , J. Larner3
  • 1Department of Surgical Sciences, Division of Clinical Physiology, Karolinska Institute, Karolinska Hospital, Stockholm, Sweden
  • 2Department of Clinical Chemistry II, Karolinska Institute, Huddinge Hospital, Huddinge, Sweden
  • 3Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, Virginia, U.S.A.
Further Information

Publication History



Publication Date:
23 April 2007 (online)


The rapid activation of glycogen synthase in human skeletal muscle during recovery from isometric contraction is dependent on an intact circulation, which suggests the requirement of an activating humoral factor. To determine whether the activating factor is insulin, muscle biopsies were obtained from subjects at rest, at fatigue, 3 min postexercise with an intact circulation, and 3 min postexercise during which circulation to the muscle was occluded. Two inositol phosphoglycan mediators of insulin action were isolated from the biopsies, and bioactivity was measured by determining the effects of the isolated mediators on the activities of purified cyclic AMP-dependent protein kinase, pyruvate dehydrogenase phosphatase and glycogen synthase phosphatase in vitro. Bioactivity was not altered by any condition compared with rest. These data suggest that changes in inositol phosphoglycans are not responsible for the circulation-dependent activation of glycogen synthase during recovery from exercise.