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. Prior eccentric contractions impair maximal insulin action on muscle glucose uptake in the conscious rat.J. Appl. Physiol. 82(4):1327-1332, 1997.Our aim was to examine the effect of prioreccentric contractions on insulin action locally in muscle in theintact conscious rat. Anesthetized rats performed one-leg eccentriccontractions through the use of calf muscle electrical stimulationfollowed by stretch of the active muscles. Two days later, basal andeuglycemic clamp studies were conducted with the rats in the awakefasted state. Muscle glucose metabolism was estimated from2-[¹⁴C(U)]deoxy-D-glucoseandD-[3-³H]glucose administration, and comparisons were made between the eccentrically stimulated and nonstimulated (control) calfmuscles. At midphysiological insulin levels, effects ofprior eccentric exercise on muscle glucose uptake were notstatistically significant. Maximal insulin stimulation revealed reducedincremental glucose uptake above basal(P < 0.05 in the red gastrocnemius;P < 0.1 in the white gastrocnemiusand soleus) and impaired net glycogen synthesis in all eccentricallystimulated muscles (P < 0.05). Weconclude that prior eccentric contractions impair maximal insulin action (responsiveness) on local muscle glucose uptake and glycogen synthesis in the conscious rat.