Fig. 1.

Men1 excision does not affect insulin secretion by islets and peripheral insulin sensitivity. Men1^l/l or Men1^l/l;Cre-ER mice at the age of 12 wk were fed tamoxifen (TAM) at 200 mg/kg of body weight per day. (A) Men1 mRNA levels in islets isolated from Men1^l/l and Men1^l/l;Cre-ER mice 30 d after TAM treatment (n = 10 mice). (B and C) Immunostaining for menin and insulin in islets from Men1^l/l (B) and Men1^l/l;Cre-ER mice (C) 30 d after TAM treatment (n = 6 mice). (Scale bar: 25 μm.) (D) Insulin release from islets isolated from Men1^l/l and Men1^l/l;Cre-ER mice 30 d after TAM treatment. One hundred size-matched islets of each genotype were hand-picked and cultured for 3 d. Insulin secretion stimulated by glucose (0–25 mM) and potassium chloride (KCl, 30 mM) were measured as described in SI Appendix. (E) Insulin tolerance test (ITT; insulin at 0.75 U/kg of body weight, i.p.) was performed in Men1^l/l and Men1^l/l;Cre-ER (n = 4–5 mice) 4 mo after TAM treatment. Test results were expressed as the percentage of baseline nonfasting blood glucose levels. ***P < 0.001.