Improved glucose tolerance and increased insulin secretion in Mitfce/ce mice. A: Blood glucose levels from random-fed and 6-h-fasted wild-type (wt/het) and Mitf mutant mice, n ≥ 9. B: Plasma glucagon levels from random-fed and 6-h-fasted wild-type and Mitfce/ce animals, n ≥ 3. C and D: IPGTT (with overnight, 12-h fasting) of 12-week (C) and 6-month-old (D) Mitf mutant and wild-type mice. Blood glucose measurements were taken at 0, 5, 15, 30, 60, and 120 min after the intraperitoneal
glucose injection (2 g of D(+) glucose/kg body wt). E: In vivo glucose-stimulated insulin secretion: intraperitoneal glucose injection with 2 g D(+) glucose/kg body wt. Insulin
levels were measured 0, 2, 5, and 15 min after injection; n ≥ 10. t test, *P value <0.05, **P value < 0.01. F: Insulin secretion profile of Mitfce/ce mice. Islets isolated from Mitfce/ce and control mice treated with different glucose concentrations (2.8, 8.3, and 16.7 mmol/L glucose and 16.7 mmol/L glucose
plus 35 mmol/L KCl). Insulin levels were assessed with insulin ELISA; n ≥ 3. **P value < 0.01 with two-way ANOVA.