FIG. 6.

Islet preservation under the different mitochondrial treatments. A: To exclude a damaging and nonspecific oxidative stress, lipid peroxidation was evaluated. Hydroperoxides were evaluated on islets treated in static incubation for 30 min with 100 μmol/l rotenone, 1 μmol/l CCCP, or 20 μmol/l antimycine compared with basal conditions, 5.5 mmol/l glucose. No difference in these groups compared with glucose was observed. B: Insulin resecretion after the 100 μmol/l rotenone or 20 μmol/l antimycin treatment consisted to expose islets to GSIS after they were stimulated with the mitochondrial blockers for 30 min and insulin was measured in the milieu. They were replaced in basal glucose (5.5 mmol/l) for 30 min further, and insulin was reevaluated before a GSIS was done. In these conditions, insulin release was absent in the milieu in basal conditions, and the ability of glucose to restimulate insulin secretion was totally maintained after the pharmacological treatments. Three independent experiments, n = 6; ***P < 0.001, glucose 16.7 vs. 5.5 mmol/l. Bars represent SE in all figures. They were not represented for perifused-islet experiments. Ant, antimycin; rot, rotenone.