Metabolic profiles of the experimental groups. (A) Blood glucose levels for the rats treated with STZ and vehicle. Each marker represents the value measured in each rat belonging to different groups (shown in the inset). The horizontal bars indicate the mean of blood glucose levels for each group. Left, values measured at 1 week (wk) after STZ injection; ***P < 0.001 (Mann–Whitney U-test) between STZ-treated (open circles) and vehicle-treated (open squares) groups. Each experimental group was composed of 20 rats. Right, values measured at 6 weeks (wks) after STZ injection; ***P < 0.001 (Mann–Whitney U-test) between STZ-treated (circles and triangles) and vehicle-treated (squares and diamonds) groups; NS, not significantly different (Kruskal-Wallis one-way ANOVA) between saline + DW, saline + DLX, DSP-4 + DW and DSP-4 + DLX groups in the rats treated with STZ and vehicle. Each experimental group was composed of 5 rats. (B) Time course of body weights of the rats treated with STZ and vehicle. At week 0, the rats received i.v. injection of STZ (n = 20 rats) or vehicle (n = 20) (arrow on the left-bottom). At 4 weeks after STZ injection, the rats received i.p. injection of DSP-4 (n = 10 rats) or saline (n = 10) (black arrowhead). The mean and SEM (vertical bars) values of 10 rats for each experimental group are shown. **P < 0.01; ***P < 0.001 (ANOVA repeated-measures) between STZ-treated (circles) and vehicle-treated (squares) groups; ###P < 0.001 (ANOVA repeated-measures) between vehicle + saline (open squares) and vehicle + DSP-4 (filled squares) groups; NS, not significantly different (ANOVA repeated-measures) between STZ + saline (open circles) and STZ + DSP-4 (filled circles) groups.