Fig. 5

GLUT4 immunofluorescence in skeletal muscle. The diabetic Sprague–Dawley rats model was induced by feeding HFD for 8 weeks, followed by a single STZ injection (30 mg/kg). The rats were either provided HFD ab libitum (HFD + AL + STZ group) or fed HFD with a 30% restriction regimen (HFD + CR + STZ group). Rats given free access to normal chow diet served as a blank control (ND + AL group). All interventions lasted for 20 weeks. a Representative images of GLUT4 immunofluorescence in skeletal muscle (× 100). b Densitometric measurements of the average fluorescence were performed by ImageJ 1.52q. Data were from at least three independent experiments and presented as the mean ± standard deviation (SD). *p < 0.05 between the two groups; CR, calorie restriction; HFD, high-fat diet; STZ, streptozotocin; ND + AL, normal diet provided ad libitum (BCT group); HFD + AL + STZ, HFD provided ad libitum and STZ injection (MCT group); HFD + CR + STZ, HFD with 30% CR and STZ injection (CR group)