Arterial and hepatic sinusoidal plasma insulin levels in conscious dogs during the basal (−40 to 0 min) and experimental (0–240 min) periods treated with vehicle (○) or vildagliptin (▪) (means ± SE; n = 6 per group). Arterial and hepatic sinusoidal plasma insulin levels in conscious dogs during the basal (−40 to 0 min) and experimental (0–240 min) periods treated with vehicle (○) or vildagliptin (▪) (means ± SE; n = 6 per group). Dale S. Edgerton et al. Diabetes 2009;58:243-249 ©2009 by American Diabetes Association