Fig. 3. Effect of the proportion of free fatty acids (FFAs) on the function and viability of MIN6 (mouse insulinoma). The concentration of fatty acids corresponding to the lipid profile of obese adolescents with metabolic syndrome (OWMS) adolescents was adjusted to the total quantity of FFAs present in the serum of normal weight (NW) adolescents (103.25 mg/dL), but the original proportions were conserved (Table 2). MIN6 cells were treated for 24 (A, C) or 48 hours (B, D) with the NW or OWMS profiles. Control cells were grown without adding fatty acids. (A, B) The cells were maintained in baseline conditions of insulin secretion (2 mmol/L glucose in phosphate-buffered saline) and then stimulated with 25 mmol/L glucose in culture medium lacking both FFAs and fetal bovine serum. The percentage change in glucose-stimulated insulin secretion (GSIS) is shown. (C, D) Cellular viability was determined using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, normalized to the control and expressed as the viability percentage. ^aIndicates P<0.05, ^bP<0.01, using analysis of variance followed by Tukey test of multiple comparisons. The cells were treated with methanol as negative control for viability.