Figure 5.

Role of Ib1 in impaired glucose-induced insulin secretion caused by palmitate. For measurement of insulin secretion, MIN6 cells were transiently transfected with the control siRNA (open bar) or siIB1 (filled bar) or the plasmids coding for the wild type HA-tagged IB1 (IB1). 48 hrs after transfection, insulin secretion was stimulated by preincubating the cells for 30 min in Krebs-Ringer buffer containing 2 mmol/L glucose and, thereafter, incubating the cells with glucose 20 mmol/L. The amounts of insulin release and cellular contents during the incubation period were measured by EIA. The results are expressed as the ratio between the amounts of insulin released over the content and are the mean ± SEM of three independent experiments.