Figure 3

Effect of 30 mM glucose or 2.5 mM fructose on NAD(P)H autofluorescence and mitochondrial electrical membrane potential. INS-1 cells incubated in RPMI 1640 medium supplemented or not with 1 μM CsA for 1 h or 100 μM metformin for 24 h were then incubated in complete RPMI 1640 medium supplemented or not (control) with glucose (30 mM, final concentration) or 2.5 mM fructose during 24 h. Cells were then loaded with 20 nM TMRM for 30 min and the fluorescence of NAD(P)H (blue) and TMRM (red) were imaged and quantified as in Figure 2. Results are mean±S.E. of at least five different experiments. For each experiment, the four conditions were imaged with exactly the same microscope setting. To facilitate day to day comparisons, NAD(P)H/TMRM surface distribution ratio were normalized (i.e., in order that the NAD(P)H/TMRM surface distribution ratio in control condition was 1); ^*P<0.05 versus control, ^#P<0.05 versus 30 mM glucose, ^§P<0.05 versus 2.5 mM fructose, unpaired Student's t-test. Scale bar, 47 μm