Effects of vildagliptin treatment on glycaemic variables in mice. (a, b) OGTT before and after vildagliptin treatment in mice. Circles, non-treated mice; squares, vildagliptin-treated mice. White symbols, littermate insulin-receptor-floxed control mice; black symbols, βIRKO mice. In (a), n=23 in control group and n=38 in βIRKO group; in (b), n=11–19 in each group. Plasma (c) DPP-4 activity, (d) GLP-1 and (e) insulin 5 min after oral glucose load, after vildagliptin (VIL) treatment of mice (n=11–19). Mice were fasted for 16 h and glucose (1 g/kg body weight) was administered orally. Data are expressed as mean ± SEM. *p<0.05, **p<0.01, βIRKO vs control or as indicated