Figure 2.

Effects of serum deprivation on basal and glucose-stimulated insulin secretion. INS-1 832/13 cells were grown in RPMI 1640 (11.1 mm glucose) supplemented with 10% FBS (growth medium); at 80% confluence the cells were washed and incubated in growth medium or basal serum-free medium for 16 h. Insulin secretion was measured as described in Materials and Methods. Values represent the means ± sem of six samples in a representative experiment. The figures show the means ± sem of all data from two independent experiments, each of which contained six wells per treatment group. Statistically significant differences between the experimental groups are indicated by asterisks. *, P < 0.05; **, P < 0.01; ***, P < 0.001.