Prior eccentric contractions impair maximal insulin action on
muscle glucose uptake in the conscious rat.
Asp, Sven, Allan Watkinson, Nicholas D. Oakes, and Edward. W. Kraegen.
Copenhagen Muscle Research Centre, August Krogh Institute,
University of Copenhagen, DK-2100 Copenhagen, Denmark, Garvan
Institute of Medical Research, St. Vincent's Hospital, Sydney, NSW
2010, Australia
APStracts 3:0568A, 1996.
Our aim was to examine the effect of prior eccentric contractions on
insulin action locally in muscle in the intact conscious rat.
Anaesthetized rats performed one-legged eccentric contrac tions using
calf muscle electrical stimulation followed by stretch of the active
muscles. Two days later, basal and euglycemic clamp studies were
conducted in the awake fasted state. Muscle glucose metabolism was
estimated from 2-[14C(U)]-Deoxy-D-Glucose and [3-3H] glucose
administration, and comparisons were made between the eccentrically
stimulated and non-stimulated (control) calf muscles. At mid
-physiological insulin levels effects of prior eccentric exercise on
muscle glucose uptake were not statistically significant. Maximal
insulin stimulation revealed reduced incremental glucose uptake above
basal (P<0.05 in the red gastrocnemius, P<0.1 in the
white gastrocnemius and soleus) and impaired net glycogen synthesis
in all eccentrically stimulated muscles (P<0.05). We conclude
that prior eccentric contractions impair maximal insulin action
(responsiveness) on local muscle glucose uptake and glycogen
synthesis in the conscious rat.
Received 9 July 1996; accepted in final form 5 December 1996.
APS Manuscript Number A641-6.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996