Genetic selection of mice for high voluntary wheel running: effect on skeletal muscle glucose uptake

Effects of genetic selection for high wheel-running activity (17th generati on) and access to running wheels on skeletal muscle glucose uptake were stu died in mice with the following treatments for 8 wk: 1) access to unlocked wheels; 2) same as 1, but wheels locked 48 h before glucose uptake measurem ent; or 3) wheels always locked. Selected mice ran more than random-bred (n onselected) mice (8-wk mean +/- SE 5 8,243 +/- 711 vs. 3,719 +/- 233 revolu tions/day). Body weight was 5-13% lower for selected vs. nonselected groups . Fat pad/body weight was similar to 40% lower for selected vs. nonselected and unlocked vs. locked groups. Insulin-stimulated glucose uptake and fat pad/body weight were inversely correlated for isolated soleus (r = 0.333; P < 0.005) but not extensor digitorum longus (EDL) or epitrochlearis muscles. Insulin-stimulated glucose uptake was higher in EDL (P< 0.02) for selected vs. nonselected mice. Glucose uptake did not differ by wheel group, and am ount of running did not correlate with glucose uptake for any muscle. Wheel running by mice did not enhance subsequent glucose uptake by isolated musc les.