DT mice display abnormal insulin secretion during treadmill exercise. Male mice were subjected to treadmill exercise at a
5% incline (see research design and methods). A and B: The maximum running speed (A) and blood glucose after a 4-h fast (B) of each genotype before (−Dox) and after (+Dox) doxycycline treatment. C–G: After fasting, mice were run at 80% of maximum running speed for 20 min. Blood glucose levels (C) were measured during exercise. Plasma insulin (D), lactate (F), and pyruvate (G) were measured before and immediately after exercise. HOMA2-B% values (E) were calculated from the glucose and insulin levels. Data are presented as mean ± SEM (ST n = 10, DT n = 8). *P < 0.05 within genotypes; **P < 0.001 within genotypes; #P < 0.05 between genotypes.